OCD is a Treatable Medical Condition
What Causes OCD?

Everyone’s brain churns out random and strange thoughts. Most people simply dismiss them and move on, but they get “stuck” in the brains of people with OCD.  These random thoughts are like the brain’s junk mail. Most people have a spam filter and can simply ignore junk mail that comes their way. But having OCD is like having a spam filter that has stopped working—the junk mail just keeps coming and you cannot make it stop. Soon, the junk mail seriously outnumbers the wanted mail, and you become overwhelmed. So why does the brain of individuals with OCD work this way? In other words, what causes OCD?

Unfortunately, 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.

OCD is an anxiety disorder that has a neurobiological basis.  Using neuroimaging technologies in which pictures of the brain and its functioning are taken, scientists have shown that functioning in some areas of the brain is different in individuals who have OCD compared to those who don’t. 

Research shows that the disorder may involve communication errors that take place between the orbitofrontal cortex (front part of the brain), the striatum, and the thalamus (deeper parts of the brain).  Abnormalities in the serotonin and other neurotransmitter systems—chemicals that send messages between brain cells – also are involved in the disorder.

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—about 25% of OCD sufferers have an immediate family member with 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 symptoms after a severe infection such as strep throat.  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.


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