When does ocd develop


OCD: Some Facts

  • Symptoms
  • What causes OCD?
  • Why do you have OCD?
  • The two important associations in OCD


It is estimated that six million people in the USA have obsessive-compulsive disorder (OCD). Men and women develop OCD at similar rates and it has been observed in all age groups, from school-aged children to older adults. OCD typically begins in adolescence, but may start in early adulthood or childhood. The onset of OCD is typically gradual, but in some cases it may start suddenly. Symptoms fluctuate in severity from time to time, and this fluctuation may be related to the occurrence of stressful events. Because symptoms usually worsen with age, people may have difficulty remembering when OCD began, but can sometimes recall when they first noticed that the symptoms were disrupting their lives.

As you may already know, the symptoms of OCD include the following:

  • Unwanted or upsetting doubts
  • Thoughts about harm, contamination, sex, religious themes, or health
  • Rituals like excessive washing, checking, praying, repeating routine activities
  • Special thoughts designed to counteract negative thoughts

In addition, you may be aware of certain situations, places, or objects that trigger the distressing thoughts and urges to ritualize. You may find yourself avoiding these situations, places, and objects.

What causes OCD?

The reasons why some people develop obsessions and compulsions while others don’t are unknown. Researchers have considered different types of explanations. Some experts have suggested that some specific “thinking mistakes” about harm occur in OCD. Examples of such thinking mistakes are:

  • Thinking about an action is the same as doing it, or wanting to do it
  • People should control their thoughts
  • If I don’t try to prevent harm, it’s the same as causing harm
  • A person is responsible for harm, regardless of the circumstances

While this theory explains the types of thinking mistakes made by people with OCD, it does not explain why some people develop OCD and others do not.

Many researchers also feel that people with OCD have abnormal brain chemistry involving serotonin, a chemical that is important for brain functioning. Unusual serotonin chemistry has been observed in people with OCD and medications that relieve OCD symptoms also change serotonin levels. However, it is not known whether serotonin chemistry is truly a key factor in the development of OCD. Research results are inconclusive at this point.

There is also evidence that OCD is more prevalent in some families than others. It is difficult to know how much of this is a result of what children learn from their family while growing up, and how much is hereditary.

Why do you have OCD?

Many people would like to know what causes this disorder or how they developed it. There are a number of guesses, but there is as yet no satisfactory theory of its development. Most likely, there is a combination of factors (such as biological/genetic and environmental aspects) that contribute to the development of OCD. It is tempting to be overly concerned with the lack of information about how OCD develops. Fortunately, despite our lack of knowledge, there are effective treatments available that do not require an explanation for why or how a person developed OCD.

Scientists do understand a great deal about the symptoms of OCD and this is very important for the treatment of the disorder. In fact, your learning more about your OCD symptoms will help you get more improvement from this treatment. OCD is a set of habits that, as you know, involves intrusive, unwanted, and upsetting thoughts, ideas, images, or impulses (obsessions). Along with these thoughts, you have unwanted feelings of extreme discomfort or anxiety and string urges to do something to reduce the distress. Because of this, people get into the habit of using various special thoughts or actions to try to get rid of the anxiety (compulsive rituals). These habits of thinking, feeling and acting are extremely unpleasant, wasteful, and difficult to get rid of on your own.

The two important associations in OCD

Two types of associations are a very important part of OCD and understanding both of them will help with your therapy. Therapy is designed to break both types of associations. First is the association between certain objects, thoughts, or situations and anxiety/discomfort. For example, think about a situation, thought, or object that you try to avoid or that you endure with suffering because if makes you feel distressed or uncomfortable. It is likely that you have an association between this situation and anxiety or distress.

The second type of association is an association between carrying out rituals and decreasing the distress. In other words, after you carry out your rituals you temporarily feel less distress. Therefore, you continue to engage in this behavior frequently to achieve more relief. Try to identify the situations that increase discomfort (association #1) and then the behaviors or thoughts that you perform to neutralize the discomfort (association #2). Doing this will help you in your treatment.

Unfortunately, doing rituals to reduce distress doesn’t work all that well. Your distress goes down for a short time and comes back again. Often, you find yourself doing more and more ritualizing to try to get rid of the anxiety. Even then, the rituals do not reduce the distress, and before long, you are putting so much time and energy into rituals that other areas of your life get seriously disrupted.

In order to treat OCD, the associations described above must be weakened or broken. Your therapy is designed to do this and your therapist knows exercises that will be helpful in achieving this goal. These exercises are called exposure and ritual prevention and you will learn more about them from your treatment provider.

By experienced psychologist Fred Penzel, Ph.D.

I have been actively involved in the treatment of OCD since 1982 and have treated over 850 cases of the disorder. During that time, I have come to many valuable understandings that I believe are important tools for anyone planning to take on this disorder. Putting together this type of list always seems arbitrary in terms of what to include, but suffice it to say, however, it is presented, there is a certain body of information that can make anyone’s attempts at recovery more effective.

Some of these points may seem obvious, but it has always struck me as remarkable how little of this information my new patients, who are otherwise intelligent and informed people, are seen to possess coming into therapy.

You may not like some of the things on this list, as they may not be what you wish to hear. You don’t have to like them. However, if you wish to change, you will need to accept them. The concepts of change and acceptance go hand-in-hand and define each other. There are some things you will be able to change, and some you will have to accept. It is important to discriminate between the two, so as to not end up misdirecting your efforts.

My list is as follows:

1. OCD is chronic

This means it is like having asthma or diabetes. You can get it under control and become recovered but, at the present time, there is no cure. It is a potential that will always be there in the background, even if it is no longer affecting your life. The current thinking is that it is probably genetic in origin, and not within our current reach to treat at that level. The things you will have to do to treat it really control, and if you don’t learn to effectively make use of them throughout your life, you will run the risk of relapse. This means that if you don’t use the tools provided in cognitive/behavioral therapy or if you stop taking your medication (in most cases) you will soon find yourself hemmed in by symptoms once again.

2. Two of the main features of OCD are doubt and guilt

While it is not understood why this is so, these are considered hallmarks of the disorder. Unless you understand these, you cannot understand OCD. In the 19th century, OCD was known as the “doubting disease.” OCD can make a sufferer doubt even the most basic things about themselves, others, or the world they live in. I have seen patients doubt their sexuality, their sanity, their perceptions, whether or not they are responsible for the safety of total strangers, the likelihood that they will become murderers, etc. I have even seen patients have doubts about whether they were actually alive or not. Doubt is one of the more maddening qualities of OCD. It can override even the keenest intelligence. It is a doubt that cannot be quenched. It is doubt raised to the highest power. It is what causes sufferers to check things hundreds of times, or to ask endless questions of themselves or others. Even when an answer is found, it may only stick for several minutes, only to slip away as if it was never there. Only when sufferers recognize the futility of trying to resolve this doubt, can they begin to make progress.

The guilt is another excruciating part of the disorder. It is rather easy to make people with OCD feel guilty about most anything, as many of them already have a surplus of it. They often feel responsible for things that no one would ever take upon themselves

3. Although you can resist performing a compulsion, you cannot refuse to think an obsessive thought

Obsessions are biochemically generated mental events that seem to resemble one’s own real thoughts, but aren’t. One of my patients used to refer to them as “My synthetic thoughts.” They are as counterfeit bills are to real ones, or as wax fruit is to real fruit. As biochemical events, they cannot simply be shut off at will. Studies in thought suppression have shown that the more you try to not think about something, the more you will end up thinking about it paradoxically. The real trick to dealing with obsessions I like to tell my patients is, “If you want to think about it less, think about it more.” Neither can you run from or avoid the fears resulting from your obsessions. Fear, too, originates in the mind, and in order to recover, it is important to accept that there is no escape. Fears must be confronted. People with OCD do not stay with the things they fear long enough to learn the truth–that is, that their fears are unjustified and that the anxiety would have gone away anyway on its own, without a compulsion or neutralizing activity.

4. Cognitive/Behavioral Therapy is the best form of treatment for OCD

Cognitive/Behavioral Therapy (CBT) is considered to be the best form of treatment for OCD. OCD is believed to be a genetically-based problem with behavioral components, and not psychological in origin. Ordinary talk therapy will, therefore, not be of much help. Reviewing past events in your life, or trying to figure out where your parents went wrong in raising you have never been shown to relieve the symptoms of OCD. Other forms of behavioral treatment, such as relaxation training or thought-stopping (snapping a rubber band against your wrist and saying the word “Stop” to yourself when you get an obsessive thought) are likewise unhelpful. The type of behavioral therapy shown to be most effective for OCD is known as Exposure and Response Prevention (E&RP).

E&RP consists of gradually confronting your fearful thoughts and situations while resisting the performing of compulsions. The goal is to stay with whatever makes you anxious so that you will develop a tolerance for the thought or the situation, and learn that, if you take no protective measures, nothing at all will happen. People with OCD do not stay long enough in feared situations to learn the truth. I try to get my patients to stay with fearful things to the point where a kind of fatigue with the subject sets in. Our goal is to wear the thought out. I tell them, “You cant be bored and scared at the same time.” Compulsions, too, are part of the system and must be eliminated for the recovery process to occur. There are two things that tend to sustain compulsions. One is that by doing them, the sufferer is only further convinced of the reality of their obsessions, and is then driven to do more compulsions. The other is that habit also keeps some people doing compulsions, sometimes long after the point of doing them is forgotten. The cognitive component of CBT teaches you to question the probability of your fears actually coming true (always very low or practically nil), and to challenge their underlying logic (always irrational and sometimes even bizarre).

5. While medication is a help, it is not a complete treatment in itself

It is human nature to always want quick, easy, and simple solutions to life’s problems. While everyone with OCD would like there to be a magical medicinal bullet to take away their symptoms, there really is no such thing at this time. Meds are not the “perfect” treatment; however, they are a “pretty good” treatment. Generally speaking, if you can get a reduction in your symptoms of from 60 to 70 percent, it is considered a good result. Of course, there are always those few who can say that their symptoms were completely relieved by a particular drug. They are the exception rather than the rule. People are always asking me, “What is the best drug for OCD?” My answer is, “The one that works best for you.” I have a saying about meds: “Everything works for somebody, but nothing works for everybody.” Just because a particular drug worked for someone you know, does not mean that it will work for you.

Relying solely on meds most likely means that all your symptoms will not be relieved and that you will always be vulnerable to a substantial relapse if you discontinue them. Discontinuation studies (where those who have only had meds agreed to give them up) have demonstrated extremely high rates of relapse. This is because drugs are not a cure, but are rather a control. Even where they are working well, when you stop taking them, your chemistry will soon revert (usually within a few weeks) to its former unhealthy state. Meds are extremely useful as part of a comprehensive treatment together with CBT. They should, in fact, be regarded as a tool to help you to do therapy. They give you an edge by reducing levels of obsession and anxiety. While those with mild OCD can frequently recover without the use of meds, the majority of sufferers will need them in order to be successful. One unfortunate problem with meds is the stigma attached to them. Having to use them does not mean that you are weaker than others, only that this is what your particular chemistry requires for you to be successful. You cant always fight your own brain chemistry unaided. Using psychiatric drugs also does not mean that you are “crazy.” People with OCD are not crazy, delusional, or disoriented. When relieved of their symptoms, they are just as functional as anyone.

6. You cannot and should not depend upon the help of others to manage your anxiety or to get well

To begin with, and most obviously, you are always with you. If you come to depend upon others to manage your anxiety by reassuring you, answering your questions, touching things for you, or taking part in your rituals, what will you do when they are not around? My guess is that you will likely be immobilized and helpless. The same is true if you only work on your therapy homework when others are nagging or reminding you. No one can want you to recover more than you do. If your motivation is so poor that you cannot get going on your own (assuming that you are not also suffering from an untreated case of depression), then you will have learned nothing about what it takes to recover from OCD. As mentioned at the beginning, since OCD is chronic, you will have to learn to manage it throughout your life. Since you can find yourself on your own at any point, unpredictably, you will always need to be fully independent in managing it.

7. The goal of any good treatment is to teach you to become your own therapist

In line with the last point, good Cognitive/Behavioral treatment should aim to give you the tools necessary to manage your symptoms effectively. As therapy progresses, the responsibility for directing your treatment should gradually shift from your therapist to you. Whereas the therapist may start out by giving you assignments designed to help you face and overcome your fears, you should eventually learn to spot difficult situations on your own and give yourself challenging homework to do. This will then be a model for how you will need to handle things throughout your life.

8. You cannot rely upon your own intuition in deciding how to deal with OCD

In using your intuition to deal with what obsessions may be telling you, there is one thing you can always count on: it will always lead you in the wrong direction. It is only natural to want to escape or avoid that which makes you fearful. It’s instinctive. It really amazes me how common this is. This may be fine when faced by a vicious dog or an angry mugger but, since the fear in OCD results from recurring thoughts inside your head, it cannot be escaped from. The momentary escape from fear that compulsions give fools people into relying upon them. While compulsions start out as a solution, they soon become the main problem itself as they begin taking over your life. People with OCD never stay with what they fear long enough to find out that what they fear isn’t true. Only by doing the opposite of what instinct tells you will you be able to find this out.

9. Getting recovered takes time

How long does it take? As long as is necessary for a given individual. Speaking from experience, I would say that the average uncomplicated case of OCD takes from about six to twelve months to be successfully completed. If symptoms are severe, if the person works at a slow pace, or if other problems are also present, it can take longer. Also, some people need to work on the rehabilitation of their lives after the OCD is brought under control. Long-term OCD can take a heavy toll on a persons ability to live. It may have been a long time since they have socialized, held a job, or doing everyday household chores, etc. Some people have never done these things. Returning to these activities may add to the time it takes to finish treatment.

However long it takes, it is crucial to see the process through to the finish. There is no such thing as being “partially recovered.” Those who believe they can take on only those symptoms they feel comfortable facing soon find themselves back at square one. Untreated symptoms have a way of expanding to fill the space left by those that have been relieved. When explaining this to my patients, I liken it to getting surgery for cancer. I ask them, “Would you want the surgeon to remove it all, or leave some of it behind?” Or, put another way, it is not a game you can simply drop out of midway with your winnings and expect to keep them.

10. Relapse is a potential risk that must be guarded against

It has always been a favorite saying of mine that, “Getting well is 50 percent of the job, and staying well is the other 50 percent.” We have actually come full-circle back to Point #1, which tells us that OCD is chronic. This tells us that although there is no cure, you can successfully recover and live a life no different from other people. Once a person gets to the point of recovery, there are several things that must be observed if they are to stay that way. As mentioned in Point #7, the goal of proper therapy is to teach people to become their own therapists. It gives them the tools to accomplish this. One of these tools is the knowledge that feared situations can no longer be avoided. The overall operating principle is that obsessions must therefore always be confronted immediately, and all compulsions must be resisted. When people are seen to relapse, it is usually because they avoided an obsessive fear which then got out of hand because they went on to perform compulsions. Another cause can be an individual believing that they were cured and stopping their medication without telling anyone. Unfortunately, the brain doesn’t repair itself while on medications, and so when drugs are withdrawn, the chemistry reverts to its former dysfunctional state. Finally, some people may have fully completed their treatment, but have neglected to tell their therapist about all of their symptoms, or else they did not go as far as they needed to in confronting and overcoming the things they did work on. In pursuing treatment for OCD, it is vital to go the distance in tackling all of your symptoms, so as to be prepared for whatever you may encounter in the future.

It is vital to remember that no one is perfect, nor can anyone recover perfectly. Even in well-maintained recoveries, people can occasionally slip up and forget what they are supposed to be doing. Luckily, there is always another chance to re-expose yourself and so, rather than a person beating themselves up and putting themselves down, they can soon regain their balance if they immediately get back on track by turning again and facing that which is feared, and then not doing compulsions.

Finally, because health is the result of living in a state of balance, it is extremely important, post-therapy, to live a balanced life, with enough sleep, proper diet and exercise, social relationships, and productive work of some type.

Fred Penzel, Ph.D. is a licensed psychologist who has specialized in the treatment of OCD and related disorders since 1982. He is the executive director of Western Suffolk Psychological Services in Huntington, Long Island, New York, a private treatment group specializing in OCD and obsessive-compulsive related problems, and is a founding member of the OCF Science Advisory Board. More of Fred’s work can be found on his website. Dr. Penzel is the author of “Obsessive-Compulsive Disorders: A Complete Guide To Getting Well And Staying Well,” a self-help book covering OCD and other obsessive-compulsive spectrum disorders.

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Living with Pure OCD

How Do I Know it’s OCD?

Everyone gets intrusive thoughts, but having them doesn’t mean you have OCD. For people who do have OCD, these thoughts can be debilitating, causing extreme anxiety and discomfort. No matter how hard you try to get rid of them, they won’t go away.

Having intrusive thoughts does not make you a bad person. They are a misfiring in the brain, not a reflection of your character.

Everyday examples:

  • Your roommates are always touching everything: the refrigerator handle, the faucet, the bathroom light switch. You can’t touch any of those things without putting your sleeve over your hand. See Contamination OCD.
  • Pulling out a kitchen knife and immediately thinking about how it could be used to harm your partner. See Harm OCD.
  • You think your partner has bushy eyebrows. You pinpoint this “flaw” and think that you couldn’t possibly be with someone like this for the rest of your life. You start thinking that it’s time to find someone who has better-looking eyebrows. See Relationship OCD.

How can my family help my Pure OCD?

When it comes to family and friends, your thoughts can be confusing for them to understand. In their minds, the situations you’re obsessing over are clearly unrealistic. Often times, they’ll want to provide reassurance that you are not capable of the things going on in your mind. Unfortunately, enabling you in this way can actually make your OCD worse. It provides momentary relief, but over time, the thoughts strengthen. Involving your family in therapy can be a good way to help them understand the do’s and don’ts of the disorder, and create a game plan for helping you at home.

Is Recovery Possible for Me?

Yes! People with Pure OCD can get much better through Exposure Response Prevention Therapy (ERP). ERP is when you voluntarily expose yourself to the source of your fear over and over and over again, without acting out any compulsion to neutralize or stop the fear. By repeatedly facing something you’re afraid of, you force your brain to recognize how irrational it is. ERP Therapy varies greatly depending on the nature of a person’s Pure OCD. Someone with Harm OCD will need to tackle different fears than someone with Contamination OCD. It is crucial you work with a professional who is well versed in the disorder.

Examples of ERP treatment:

  • To start, a person with Harm OCD may be asked carry a plastic fork or plastic knife in their pocket and create an association with that item. As time goes on, they’ll build on these items until they’re carrying more threatening objects like sharp kitchen knives or scissors.
  • Or, a person with Contamination OCD may start by making a list of things they’re afraid of like touching door handles or not washing hands. Then, they’ll start the exposure exercises starting with the relatively low-level anxiety tasks. The tasks will become more challenging as they move down the list. Soon, they might be doing things like handing a homeless person a quarter or touching the faucet in a public bathroom.

There are other treatment options as well. Mindfulness-based Cognitive Behavioral Therapy, also known as CBT, teaches people to identify, understand and change negative thinking patterns and behaviors. Patients are taught problem-solving skills during therapy lessons and then instructed to practice them on their own time in order to build positive habits.

Can medication help?

Medication can help alongside ERP, but it shouldn’t replace it. Doctors should always be consulted before considering medicinal options.

The main family of medicines used to treat OCD are known as Selective Serotonin Reuptake Inhibitors, or SSRIs. SSRIs enhance your natural serotonin activity and are used to treat major depressive disorders and anxiety conditions. Examples include Lexapro, Prozac, Paxil and Zoloft.

What is the goal of therapy?

Some people with Pure OCD recover completely through ERP. But for many, their obsessions never fully go away. OCD recovery has more to do with managing the condition, than it does with eliminating it. However, that doesn’t mean you can’t lead a healthy, happy life. By prioritizing treatment and positive lifestyle habits, sufferers often gain confidence and freedom. Even if some anxiety is still present by the end of therapy, you’ll no longer feel debilitated by the condition.

If you suffer from OCD, you have a severe anxiety disorder. But it can be treated. Start by getting educated and making healthy living choices. Then find a clinical psychologist in your area who specializes in OCD and Exposure Response Prevention (ERP).

At What Age Does OCD Usually Begin?

Everyday Health: Does obsessive-compulsive disorder usually begin at a certain age? Can someone go through life without having OCD, and then suddenly start showing symptoms as an older person?

Jeff Szymanski, PhD (ocfoundation.org)

OCD can start at any time from preschool to adulthood. Although OCD does occur at earlier ages, there are generally two age ranges when OCD first appears: Between ages 10 and 12 and between the late teens and early adulthood.

Jonathan Abramowitz, PhD (jabramowitz.com)

It typically starts between 18 and 25 but can begin anytime. I’ve met kids as young as 6 or 7 years old with it. It’s less likely to show up for the first time the older you get, except when women become pregnant and deliver babies, they’re at greater risk for developing OCD symptoms.

Steven J. Brodsky, PsyD (OCDHotline.com)

The average age of onset is 7 years old, and there are cases that include infants. Often people think it developed later in life, but that’s just when it was identified. Many times, people mistakenly think their OCD has magically disappeared for years and then it reoccurs. In reality, all that disappeared were their circumstances, routine, setting, and triggers, but it all comes back when circumstances change again. Frequently this can be around life transitions. Sometimes, OCD can be manageable but then become acute due to medical circumstances, such as pregnancy and childbirth.

Charles H. Elliott, PhD, and Laura L. Smith, PhD (psychology4people.com)

OCD often strikes in childhood, although it’s relatively rare before the ages of four or five. Although people can develop OCD symptoms at any time in their lives, typically symptoms appear by young adulthood, if not before.

Kenneth Schwarz, PhD (DutchessPsychology.com)

OCD symptoms can begin at any age, even in later adulthood. Usual onset is in adolescence, with boys showing a trend to earlier onset than girls. For children younger than adolescence, OCD symptoms are similar to the ones adults experience.

Charlotte M. Scott (custommovesolutions.com)

OCD has no age recognition; trauma and severe grief can trigger the disorder at any age. Although it appears that the fears, obsession, and compulsions can be “learned” by children and teens in the household of a person who suffers from OCD.

Allen H. Weg, EdD (stressandanxiety.com)

Most adults can trace early signs of OCD back to childhood, but plenty of people experience the initial onset at early adolescence. It is believed that a combination of the hormonal changes that take place at that age, together with the growing demands and responsibilities of life might play a role. A much smaller percentage of individuals experience OCD onset after age 30. This is rare, but does seem to happen on occasion.

Controversy Time!

In spite of a range of theories and considerable research, scientists so far have not been able to identify a definitive cause for why a person develops Obsessive-Compulsive Disorder (OCD).

However, there are plenty of theories surrounding the potential causes of OCD, involving one of or a combination of either; neurobiological, genetic, learned behaviours, pregnancy, environmental factors or specific events that trigger the disorder in a specific individual at a particular point in time.

We will summarise some of the suggested theories on this page, but before we begin it’s important we make it clear that this is just theory.

There have been many explanations of why people develop OCD. Some have argued that it is inherited, whilst others have said that life events can cause it. Others have suggested that it’s caused by a chemical imbalance in the brain. Different people, different researchers find different explanations more helpful than others. But here’s the point, we simply don’t know!

So let’s summarise some of those explanations.

Biological Factors

Some mental health researchers have encouraged us to think of research on brain scans and similar as indicating that OCD is linked to a genetic or biological cause. This research is often described in terms of chemical imbalances in the brain, faulty brain circuitry or genetic defects.

However, despite the recognition that certain parts of the brain are different in OCD sufferers, when compared with non-sufferers, it is still not known how these differences relate to the precise mechanisms of OCD.

Brain imaging studies have consistently demonstrated differing blood flow patterns among people with OCD compared with controls, and the cortical and basal ganglia regions are most strongly implicated. However, subsequent meta-analysis studies found that differences between people with OCD and healthy controls were found consistently only in the orbital gyrus and the head of the caudate nucleus.

So yes, whilst it’s true to say that sometimes people with OCD are found to have different brain activity, it could be argued this would be expected.

A brain scan is sensitive to different patterns of activity in the brain and can, for example, detect the difference in terms of the way the brain reacts between expert musicians listening to music and people with no special knowledge of music.

These areas of the brain become relevant and ‘switched on’ in particular environments where the person is worrying. It is therefore not surprising that there are brain activation differences between people with OCD and those without; this does not mean that OCD is a biological disease.


A 1998 finding implicated the basal ganglia as a key brain region in OCD with the discovery that in a sub-group of children with OCD the disorder may have been triggered by infections.

Streptococcal infections trigger an immune response, which in some individuals generates antibodies that cross-react with the basal ganglia. The explanation was that some children begin to exhibit OCD symptoms after a severe strep throat infection. It is thought that the body’s natural response to infection, the production of certain antibodies, when directed to parts of the brain might be linked in some way to Paediatric Autoimmune Neuropsychiatric Disorders associated with Streptococcal Infection (PANDAS).

This mechanism may explain the subgroup of children in whom OCD develops after a streptococcal infection, and worsens with recurrent infections. However, a later 2004 study found no link between subsequent infections and exacerbation of symptoms.

What we do know is that if OCD results from a strep throat infection the symptoms will start quickly, probably within one or two weeks.

So it could be that PANDAS whilst not a cause for OCD, triggers symptoms in children who are already predisposed to the disorder, perhaps through genetics or other causal explanations.

Genetic Factors

Overall, genetic studies indicate some tendency towards anxiety that runs in families, although this is probably only slight.

Some research points to the likelihood that OCD sufferers will have a family member with OCD or with one of the other disorders in the OCD ‘spectrum’. In 2001, a meta-analytic review reported that a person with OCD is 4 times more likely to have another family member with OCD than a person who does not have the disorder.

This and other studies have raised the possibility of familial prevalence of OCD and led to a search to identify specific genetic factors that may be involved. S However, despite a proliferation of studies, and dozens of potential gene candidates suggested, researchers have so far failed to identify a consistent candidate gene responsible for OCD.

It also needs to be remembered that many sufferers do not identify OCD anywhere else in their family, or even other anxiety problems. This theory could be further questioned based on speaking to identical twins where one will have OCD and the other has no anxiety problem at all.

What this suggests is that genetics may not be the only cause of OCD (if at all), and that family prevalence of OCD could be learned behaviours in some cases. So although we cannot rule genetics out, it’s clear that it’s not the whole story and learned or environment factors may play a more significant part.

In summary, there is no obvious benefit to offering biological explanations for the cause of OCD, especially if such suggestions lead those who suffer to dismiss existing psychological treatment methods.

Chemical Imbalance

It’s common to see and hear mental health professionals describing the cause of OCD in terms of a ‘biochemical imbalance’. These approaches have focused on one particular neurotransmitter, serotonin.

Serotonin is the chemical in the brain that sends messages between brain cells and it is thought to be involved in regulating everything from anxiety, to memory, to sleep.

Through the accidental discovery in the late sixties of the effectiveness of the serotonin active tricyclic antidepressant clomipramine, which did not substantially impact on serotonin, led to the serotonin hypothesis.

Initially, it was suggested that there was a gross deficit in serotonin; when this was not actually identified, increasingly subtle abnormalities were suggested, with the evidence overall remaining implausible at best.

In more recent years some researchers have argued that the most robust evidence for the serotonin hypothesis is the specificity of serotonin reuptake inhibitors (SRI) and selective serotonin reuptake inhibitor (SSRI) medication.

However, given that this effect was the observation that generated the hypothesis, it cannot reasonably be considered as evidence for it.

It’s worth noting that relapse is frequently associated with the withdrawal of SSRI medications in OCD, more so than in other conditions, especially where no behavioural therapy is in place, which is yet to be fully understood. This could mean that serotonin is an important neurotransmitter involved in the maintenance of OCD, if not a specific cause.

Overall, there is a place for SSRIs in the treatment of OCD, especially where co-morbidity is present, provided that medication remains part of informed patient choice, and combined with psychological therapy like CBT.

Psychological Theories

Other research has revealed that there may be a number of other factors that could play a role in the onset of OCD, including behavioural, cognitive, and environmental factors.

For example, according to the Learning Theory, OCD symptoms are a result of a person developing learned negative thoughts and behaviour patterns, towards previously neutral situations which can result from life experiences.

Research has revealed a great deal about the psychological factors that maintain OCD, which in turn has led to effective psychological treatment in the form of Cognitive Behavioural Therapy (CBT).

Behavioural Theory – Learned Theory

During the 50s and 60s researchers reported the successful behaviour treatment of two cases of chronic obsessional neurosis (a forerunner for the Obsessive-Compulsive Disorder name), followed by a series of successful case reports.

This discovery and research heralded the application of psychological models to obsessions and the development of effective behavioural treatments.

This research later proposed that ritualistic behaviours were a form of learned avoidance.

Behaviour therapy for phobias had proved successful in the treatment of phobic avoidance through desensitisation, but attempts to generalise these methods to compulsions had been unsuccessful.

Researchers argued that it was necessary to tackle avoidance behaviours directly by ensuring that compulsions did not take place within or between treatment sessions. This thinking anticipated cognitive approaches in that they emphasised the role of the expectations of harm in obsessions and the importance of invalidating these expectations during treatment, but this was subsequently regarded as peripheral to the major task of preventing compulsions.

Around the same time in the early seventies other researchers developed treatment methods in which exposure to feared situations was the central feature. These differing approaches were subsequently incorporated into a highly effective programme of behavioural treatment incorporating the principles of what we now refer to as exposure and response prevention (ERP).

Support for the use of this method came from a series of experiments in which it was demonstrated that, when a ritual is provoked, discomfort and the urge to ritualise spontaneously subside when no rituals (compulsions) take place.

These researchers elegantly specified the behavioural theory of OCD, that behavioural treatment of OCD is based on the hypothesis that obsessional thoughts have through conditioning, become associated with anxiety that has failed to extinguish.

Sufferers have developed avoidance behaviours (such as obsessional checking and washing), which prevent the extinction of anxiety. This leads directly to the behavioural treatment known as ERP, in which the person is: (a) exposed to stimuli that provoke the obsessional response, and (b) helped to prevent avoidance and escape (compulsive) responses.

An important contribution to the development of ERP was the observation that the occurrence of obsessions leads to an increase in anxiety, and that the compulsions lead to its subsequent attenuation. When the compulsions were delayed or prevented, people with OCD experienced a spontaneous decay in anxiety and the urges to perform compulsions. Continued practice led to the extinction of anxiety. The ‘spontaneous decay experiments’ that demonstrated this were crucial both for therapists and patients to be confident that, if they confronted their fears, anxiety and discomfort would diminish and ultimately disappear.

These early behavioural theories and experiments set the stage for later cognitive-behavioural theory and treatment.

Cognitive theory

Many cognitive theorists believe that individuals with OCD have faulty beliefs, and that it is their misinterpretation of intrusive thoughts that leads to OCD.

According to the cognitive model of OCD, everyone experiences intrusive thoughts from time-to-time. However, people with OCD often have an inflated sense of responsibility and misinterpret these thoughts as being very important and significant which could lead to catastrophic consequences.

The repeated misinterpretation of intrusive thoughts leads to the development of the obsessions and because the thoughts are so distressing, the individual engages in compulsive behaviour to try to resist, block, or neutralise the obsessive thoughts.

The cognitive-behavioural theory developed following a focus on the meaning attributed to internal (or external) events. The cognitive-behavioural theory builds on behavioural theory as it begins with an identical proposition that obsessional thinking has its origins in normal intrusive cognitions. However, in the cognitive theory the difference between normal intrusive cognitions and obsessional intrusive cognitions lies not in the occurrence or even the (un)controllability of the intrusions themselves, but rather in the interpretation made by people with OCD about the occurrence and/or content of the intrusions.

If the appraisal is focused on harm or danger, then the emotional reaction is likely to be anxiety. Such evaluations of intrusive cognitions and consequent mood changes may become part of a mood-appraisal negative spiral but would not be expected to result in compulsive behaviour. Cognitive-behavioural models therefore propose that normal obsessions become problematic when either their occurrence or content are interpreted as being personally meaningful and threatening, and it is this interpretation which mediates the distress caused.

Thus, according to the cognitive hypothesis, researchers have hypothesised that OCD would occur if intrusive cognitions were interpreted as an indication that the person may be, may have been, or may come to be, responsible for harm or its prevention.

Central to how threatening this appraisal is the idea of not only how likely the outcome is, but how ‘awful’ this is to the individual. Furthermore, this is set against the individual’s sense of how they might cope in these circumstances.

According to cognitive models, the interpretation of an intrusive thought results in a number of voluntary and involuntary reactions which each in their turn can have an impact on the strength of belief in the original interpretation. Negative appraisals can therefore act as both causal and maintenance agents in OCD.

Some researchers believe that this theory questions the biological theory because people may be born with a biological predisposition to OCD but never develop the full disorder, while others are born with the same predisposition but, when subject to sufficient learning experiences, develop OCD.

Psychoanalytic Theory

Commonly accepted in the past, but nowadays increasingly disregarded, the psychoanalytic theory suggests that OCD develops because of a person’s fixation arising from unconscious conflicts or discomfort they experienced during infancy or childhood, or the way a person interacted with his or her parents during childhood. This theory is now quite rightly disregarded due to the failure of psychoanalytic therapy to treat OCD.


Stress and parenting styles are environmental factors that have been blamed for causing OCD, but no evidence is yet to show that. Stress does not actually cause OCD, but major stresses or traumatic life events may precipitate the onset of OCD. However, these are not thought to cause OCD, but rather trigger it in someone already predisposed to the disorder.

If left untreated, everyday anxiety and stress in a person’s life will worsen symptoms in OCD. Problems at school or work, university exam pressures and normal everyday problems that relationships can bring are all contributory factors to increasing the frequency and severity of a person’s OCD.


Depression is also sometimes thought to cause OCD, although without question depression will make OCD symptoms worse, the majority of experts believe that depression is often a consequence of OCD rather than a cause.


As you can see there is a range of factors have been identified as contributing to the cause of OCD, and there is still a great deal of theoretical contention surrounding the definitive cause.

However, despite most of the above theories offering compelling and highly informative insights, it’s a possibility that a combination of the theories may eventually be identified as the actual cause of OCD and that it is likely that for any given person a number of factors are involved.

Whilst the cause is currently still being debated, sometimes vigorously by the scientists, what is not in contention is the fact that Obsessive-Compulsive Disorder is indeed a chronic (at times), but equally very treatable medical condition.

It’s also important that we don’t become fixated on what causes our OCD at the expense of fighting and tackling it. Even if we think we have identified a cause, it won’t necessarily help us overcome OCD , so our focus must remain on tackling the problem we have right now, today, in the here and now.

What to read next:

Last Checked: 5th June 2018 Next Review Due: December 2020

Additional Reading:

  • NHS Choices (External Website)

  • National Institute for Health Research – Highlight on OCD (External Website)

  • NICE Guidelines for the treatment of OCD and BDD (External Website)


  • Book: Cognitive Behaviour Therapy for OCD (External Website)

Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of Obsessive-Compulsive Disorder or any other medical condition. OCD-UK have taken all reasonable care in compiling this information, but always recommend consulting a doctor or other suitably qualified health professional for diagnosis and treatment of Obsessive-Compulsive Disorder or any other medical condition.


By S. Evelyn Stewart, M.D., Child Psychiatrist, MGH OCD Clinics, Assistant Professor, Harvard Medical School, USA

Reprinted with permission from the OCD Newsletter, Volume 22, Number 3, Summer 2008. Published by the OC Foundation Inc., USA.
Obsessive Compulsive Disorder (OCD) is one of the most common psychiatric illnesses affecting children and adolescents. Previously thought to be rare, OCD is reported to occur in 1-3% of people. It is the fourth most common mental illness after phobias, substance abuse, and major depression. OCD has peaks of onset at two different life phases: pre-adolescence and early adulthood. Around the ages of 10 to 12 years, the first peak of OCD cases occur. This time frequently coincides with increasing school and performance pressures, in addition to biologic changes of brain and body that accompany puberty.
The second peak occurs in early adulthood, also during a time of developmental transition, when educational and occupational stresses tend to be high. It has been argued that childhood-onset OCD may represent a unique subtype of the disorder with distinct characteristics. This article focuses on OCD as it occurs in children and adolescents, compared with OCD in adults.
Numerous OCD-affected adults had childhood-onset of their illness. Sadly, many of these individuals went through childhood before recognizing that they had OCD. Without an alternate explanation, they may have come to believe that they were ‘crazy’ or that they must keep their worries and behaviors as a shameful secret. Efforts are being made to increase awareness and recognition of this treatable illness within schools and in the general population.

OCD symptoms

OCD presentation is very similar across children, adolescents and adults. People with OCD have repetitive thoughts or images that they can’t control, and the anxiety caused by these thoughts leads to impulses or actions that are distressing, time-consuming or limiting to normal functioning. Of special note, the insistence on repetitive or ‘just right’ behaviours that occurs during the ‘terrible twos’ stage in toddlers is distinct from illness-related OCD symptoms. These serve as a part of normal child development, in contrast with OCD symptoms, which impair function and distract the child from learning normal developmental tasks. One way that childhood/adolescent OCD differs from OCD in adults is that youngsters may not always realise that their thoughts, worries or behaviours are excessive. For example, while an OCD affected adult may recognize that stopping a superstitious ritual is desirable, an OCD-affected child may view the ritual as a literally protective act (e.g., a child who doesn’t want to stop being afraid of germs or to stop repetitively washing, compared with an adult who desperately wants to be able to stop and to lose the worries).
A second distinction between OCD symptoms across age groups is the content of the disabling obsessions andcompulsions. All categories of adult OCD symptoms may appear in children and adolescents, including sexual, aggressive and religious obsessions. However, rates of these symptom types tend to differ by age. Religious and somatic (body or health-related) symptoms appear to be more common in child versus adolescent or adult groups and ordering and hoarding symptoms more common in child/adolescent versus adult groups. There are also symptoms that are particularly noted in children, including ‘just right’ obsessions, compulsions involving other persons such as parents, and superstitious rituals. Another OCD symptom in childhood is the intense fear or avoidance of a ‘contaminated’ sibling, leading to marked disruption of family functioning. Across the lifespan, OCD patients often experience more than one symptom type at one time, and symptoms also frequently change over the long-term course. There are groups of symptoms that tend to go together (these symptom groups are also known as symptom dimensions or factors). This is true for children, adolescents and adults. Although a person’s symptoms may change over time, it appears that they often stay within the same symptom group for a given individual. There are four groups commonly described, that include: 1) contamination and cleaning symptoms, 2) hoarding obsessions and compulsions, 3) symmetry/ordering/repeating symptoms and 4) aggressive/religious/sexual/somatic and checking symptoms. It is presently unclear whether childhood and adult-onset OCD differ significantly in terms of their long-term course. In the longest OCD study to date on adults, after an average time of 47 years from initial assessment, 20% of patients had no symptoms and 28% had some symptoms but not full OCD. A child OCD long-term outcome meta-analysis (an analysis of combined past studies) found that 40% had no OCD symptoms and 19% had some symptoms but not full OCD when they were seen at long-term follow-up.
Potential causes of OCD in children and adolescents
OCD is believed to result from a combination of genetic, biological and environmental risk factors that combine within a specific individual at a certain time point to trigger onset of the illness. Biological or environmental triggers may include a child’s immune system response to illnesses such as strep throat. This occurs in a reported OCD subgroup of childhood-onset cases called PANDAS (Paediatric Autoimmune Neuropsychiatric Disorders associated with Streptococcus). Among children, genetic causes are thought to contribute approximately 45-65% of the risk for developing OCD. Studies have suggested that children often have differing OCD symptoms from their parents. This argues against the notion that OCD running in families is a pure a result of children imitating their parents’ OCD symptoms. Having a family history of OCD is currently one of the strongest risk predictors for developing OCD. However, this does not mean that every child of an OCD affected adult will develop this illness. Despite progress in the study of OCD genetics, no single ‘OCD gene’ has been identified as a major cause of OCD. From twin studies and family studies, genetics appear to play a larger role (having higher heritability rates) as a cause of childhood-onset versus adult-onset OCD. For example, relatives of adults with OCD possess a four-fold increased risk of developing the disorder (8%), whereas relatives of those with childhood-onset OCD have a five-to eight-fold increased risk of developing it (10-17%).

Treatment for OCD in children and adolescents

One of the first and most central aspects of OCD management for children is education. Both the child and family should be reassured that symptoms are in keeping with a known and treatable illness, rather than signaling ‘odd habits,’ misbehaviour or defiance. When lasting symptoms cause significant distress or impair family, school or social functioning, they can no longer be attributed to a passing phase. Frequently, learning that these symptoms are part of a known illness brings relief to both the child and family, by ‘demystifying’ the symptoms. Since OCD tends to worsen during times of stress, the relief associated with receiving an accurate diagnosis and treatment plan alone may lead to decreased symptom severity. Central tenets of OCD treatment are similar for childhood/adolescent and adult illness. These treatments include individual and family education, cognitive-behavioural therapy, cognitive therapy and medication management. Psychoeducation about OCD should include encouragement to minimise ritual frequency, family accommodation of symptoms and avoidance of places or activities that may trigger OCD symptoms. Although not formally studied, it is likely that families with OCD-affected children may be more inclined to attempt to ‘rescue’ the child from symptoms. Such behaviour may include conducting rituals for the child, allowing the child to avoid triggers, and responding to excessive reassurance-seeking. Unfortunately, all of these actions lead to worsening rather than improvement of OCD. The management steps beyond diagnosis and family education are to initiate cognitive-behaviour therapy (CBT) and/or a serotonin reuptake inhibitor (SRI) medication trial. Sadly, a majority of OCD affected children do not receive CBT as an initial part of their treatment plan. This is likely due to the limited community and hospital availability of CBT clinicians who are experienced with OCD. Most children who do begin CBT treatment are able to complete this approach (75%), and up to 70% of those doing CBT experience at least some improvement. Of note, treatment with either relaxation training, or ‘talking’ (psychodynamic) psychotherapy alone have not been shown to improve OCD. Serotonin-reuptake inhibitors, including selective serotonin-reuptake inhibitors (SSRI’s), and clomipramine are effective OCD treatments for children/adolescents. Between 60-70% of patients have a satisfactory response during the first two SRI trials. This form of treatment frequently leads to decrease in symptom severity rather than a ‘cure’ from symptoms, however. In addition, recent suggestions that these medications may lead to suicidal thinking in a small group of children require that special monitoring takes place, especially when starting or increasing dosage. Predictors of good response to initial OCD treatment in children (with CBT and/or an SRI) include awareness of having OCD, fewer obsessions and compulsions, less severe obsessions, lower academic and functional impairment, lower accommodation – related parental stress and absence of disruptive behaviour disorders.


Obsessive-compulsive disorder is a mental illness that frequently affects children and adolescents. It may be under-recognised by parents, teachers and other caregivers due to the secretive nature of the disorder and its associated shame. Prompt diagnosis of OCD among affected children and adolescents is necessary to limit suffering directly resulting from OCD, in addition to the distraction from normal childhood development that this illness brings. Fortunately, progress is being made in understanding the genetic and biologic underpinnings of the disorder. These advances will ideally lead to improved approaches for preventing, treating and, eventually, potentially curing this common childhood disorder.



Twenty-one percent (n=92) of the sample was represented by patients with childhood onset, while 36% (n=155) of the sample showed an adolescent onset and 43% (n=184) showed an adult onset. Patients with adult onset showed a significant female prevalence compared to the other two subgroups (χ2=10.92, p<0.05; 28% of females in the adult onset subgroup vs 11% in childhood onset and 18% in adolescent onset subgroup) and showed a significantly lower prevalence of patients receiving cognitive behavioural therapy (CBT) compared to the other two subgroups (χ2=14.5, p<0.01; 28% in adult onset subgroup were not under CBT vs 10% of the childhood onset and 19% of the adolescent onset subgroup). No significant differences among the three onset subgroups were found in terms of Yale-Brown Obsessive Compulsive Scale (Y-BOCS) scores nor in terms of psychopharmacological treatments and presence of comorbidity patterns.

Everyone experiences intrusive, random and strange thoughts. Most people are able to dismiss them from consciousness and move on. But these random thoughts get “stuck” in the brains of individuals with OCD; they’re like the brain’s junk mail. Most people have a spam filter and can simply ignore incoming junk mail. But having OCD is like having a spam filter that has stopped working – the junk mail just keeps coming, and it won’t stop. Soon, the amount of junk mail exceeds the important mail, and the person with OCD becomes overwhelmed. So why does the brain of individuals with OCD work this way? In other words, what causes OCD?

Using neuroimaging technologies in which pictures of the brain and its functioning are taken, researchers have been able to demonstrate that certain areas of the brain function differently in people with OCD compared with those who don’t. Research findings suggest that OCD symptoms may involve communication errors among different parts of the brain, including the orbitofrontal cortex, the anterior cingulate cortex (both in the front of the brain), the striatum, and the thalamus (deeper parts of the brain). Abnormalities in neurotransmitter systems – chemicals such serotonin, dopamine, glutamate (and possibly others) that send messages between brain cells – are also involved in the disorder.

Although it has been established that OCD has a neurobiological basis, research has been unable to point to any definitive cause or causes of OCD. It is believed that OCD likely is the result of a combination of neurobiological, genetic, behavioral, cognitive, and environmental factors that trigger the disorder in a specific individual at a particular point in time. Following is a discussion of how those factors may play a role in the onset of OCD.

A study funded by the National Institutes of Health examined DNA, and the results suggest that OCD and certain related psychiatric disorders may be associated with an uncommon mutation of the human serotonin transporter gene (hSERT). People with severe OCD symptoms may have a second variation in the same gene. Other research points to a possible genetic component, as well. About 25% of OCD sufferers have an immediate family member with the disorder. In addition, twin studies have indicated that if one twin has OCD, the other is more likely to have OCD when the twins are identical, rather than fraternal. Overall, studies of twins with OCD estimate that genetics contributes approximately 45-65% of the risk for developing the disorder.

A number of other factors may play a role in the onset of OCD, including behavioral, cognitive, and environmental factors. Learning theorists, for example, suggest that behavioral conditioning may contribute to the development and maintenance of obsessions and compulsions. More specifically, they believe that compulsions are actually learned responses that help an individual reduce or prevent anxiety or discomfort associated with obsessions or urges. An individual who experiences an intrusive obsession regarding germs, for example, may engage in hand washing to reduce the anxiety triggered by the obsession. Because this washing ritual temporarily reduces the anxiety, the probability that the individual will engage in hand washing when a contamination fear occurs in the future is increased. As a result, compulsive behavior not only persists but actually becomes excessive.

Many cognitive theorists believe that individuals with OCD have faulty or dysfunctional beliefs, and that it is their misinterpretation of intrusive thoughts that leads to the creation of obsessions and compulsions. According to the cognitive model of OCD, everyone experiences intrusive thoughts. People with OCD, however, misinterpret these thoughts as being very important, personally significant, revealing about one’s character, or having catastrophic consequences. The repeated misinterpretation of intrusive thoughts leads to the development of obsessions. Because the obsessions are so distressing, the individual engages in compulsive behavior to try to resist, block, or neutralize them.

The Obsessive-Compulsive Cognitions Working Group, an international group of researchers who have proposed that the onset and maintenance of OCD are associated with maladaptive interpretations of cognitive intrusions, has identified six types of dysfunctional beliefs associated with OCD:

1. Inflated responsibility: a belief that one has the ability to cause and/or is responsible for preventing negative outcomes;

2. Overimportance of thoughts (also known as thought-action fusion): the belief that having a bad thought can influence the probability of the occurrence of a negative event or that having a bad thought (e.g., about doing something) is morally equivalent to actually doing it;

3. Control of thoughts: A belief that it is both essential and possible to have total control over one’s own thoughts;

4. Overestimation of threat: a belief that negative events are very probable and that they will be particularly bad;

5. Perfectionism: a belief that one cannot make mistakes and that imperfection is unacceptable; and

6. Intolerance for uncertainty: a belief that it is essential and possible to know, without a doubt, that negative events won’t happen.

Environmental factors may also contribute to the onset of OCD. For example, traumatic brain injuries have been associated with the onset of OCD, which provides further evidence of a connection between brain function impairment and OCD. And some children begin to exhibit sudden-onset OCD symptoms after a severe bacterial or viral infection such as strep throat or the flu. Studies suggest the infection doesn’t actually cause OCD, but triggers symptoms in children who are genetically predisposed to the disorder.

Stress and parenting styles are environmental factors that have been blamed for causing OCD. But no research has ever shown that stress or the way a person interacted with his or her parents during childhood causes OCD. Stress can, however, be a factor in triggering OCD in someone who is predisposed to it, and OCD symptoms can worsen in times of severe stress.

In sum, although the definitive cause or causes of OCD have not yet been identified, research continually produces new evidence that hopefully will lead to more answers. It is likely, however, that a delicate interplay between various risk factors over time is responsible for the onset and maintenance of OCD.

What doesn’t cause OCD

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