Causes of OCD

Learn About Biological, Cognitive-Behavioral, and Psychodynamic Causes of OCD

Causes of OCD
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Many theories attempt to explain the causes of OCD. Although biological causes of OCD have come to the forefront, cognitive-behavioral and psychodynamic explanations may also help our understanding of the causes of OCD.

Causes of OCD - Biological |Theories

Biological causes of OCD have focused on a circuit in the brain which regulates primitive aspects of our behavior such as aggression, sexuality, and bodily excretions.

This circuit relays information from a part of the brain called the orbitofrontal cortex to another area called the thalamus and includes other regions such as the caudate nucleus of the basal ganglia. When this circuit is activated, these impulses are brought to your attention and cause you to perform a particular behavior that appropriately addresses the impulse.

For example, after using the restroom, you may begin to wash your hands to remove any harmful germs you may have encountered. Once you have performed the appropriate behavior -- in this case, washing your hands -- the impulse from this brain circuit diminishes and you stop washing your hands and go about your day.

It has been suggested that if you have OCD, your brain has difficulty turning off or ignoring impulses from this circuit. This, in turn, causes repetitive behaviors called compulsions and/or uncontrollable thoughts called obsessions.

For instance, your brain may have trouble turning off thoughts of contamination after leaving the restroom, leading you to wash your hands again and again.

In support of this theory, the obsessions and compulsions associated with OCD often have themes which are related to sexuality, aggression, and contamination -– the very thoughts and impulses this circuit controls.

In addition, neuroimaging studies in which scientists and doctors peer into the living brain have confirmed abnormal activity in this brain circuit among people with OCD. Specifically, people with OCD show abnormal activity in different parts of this circuit including the orbital frontal cortex, cingulate cortex and caudate nucleus of the basal ganglia.

Finally, as many people with OCD respond to treatment with medications including selective serotonin reuptake inhibitors (SSRIs) which boost the neurochemical serotonin, it has been suggested that dysregulation of this brain circuit may be related to a problem with the serotonin system.

Causes of OCD - Cognitive-Behavioral Theories

Almost everyone experiences bizarre or unexpected thoughts throughout the day. According to cognitive-behavioral theories of OCD, if you are vulnerable to OCD you are unable to ignore these thoughts. In addition, you may feel that you should be able to control these thoughts and that these thoughts are dangerous.

For example, you might believe that having these thoughts means you are going crazy or that you might actually carry out the imagined or feared behavior (such as stabbing your partner).

Because these thoughts are labeled as dangerous, you remain vigilant and watchful of them, just as you might constantly look out the window if you heard there was a burglar in the neighborhood.

Constantly noticing these thoughts further reinforces or “proves” the dangerousness of these thoughts. This sets up a vicious cycle where you become trapped monitoring these dangerous thoughts. Being trapped in this cycle can make it difficult -– if not impossible -– to focus on anything else besides the distressing thoughts and an obsession is born.

Compulsions such as hand-washing may be a learned process. For example, in response to feeling contamination, you might wash your hands. This reduces your anxiety which feels good and in turn reinforces the hand-washing behavior. Because of this reinforcement, every time you experiences the obsession (such as contamination), you carry out the compulsion (such as washing their hands) to reduce your anxiety.

Causes of OCD - Psychodynamic Theories

Psychodynamic theories of OCD stress that obsessions and compulsions are signs of unconscious conflict that you might be trying to suppress, resolve or cope with. These conflicts arise when an unconscious wish (usually related to a sexual or aggressive urge) is at odds with socially acceptable behavior.

It has been suggested that when these conflicts are extremely repulsive or distressing, you can only deal with them indirectly by transferring the conflict to something more manageable such as hand-washing, checking or ordering.

Although it has been suggested that making the person aware of these conflicts can reduce symptoms of OCD, there is little scientific evidence that this actually works.


Butcher, J.N., Mineka, S., Hooley, J.M. "Abnormal Psychology, 13th ed." 2007 Toronto, ON: Pearson.

Nolen-Hoeksema, S. "Abnormal Psychology, 4th ed." 2007 New York, NY:​ McGraw Hill.

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