Two Possible Reasons People with OCD Perform Compulsions

This is my second post in the series on obsessive-compulsive disorder (OCD)—a mental disorder associated with obsessions (recurrent intrusive urges) and compulsions (mental rituals or repetitive behaviors).¹ In my previous post, I described the nature of obsessive-compulsive disorder, the relationship between obsessions and compulsions, and the consequences of performing compulsions. I also explained the first of three aspects of OCD I was planning to discuss: The need for control.

In today’s article, I explore two other aspects of OCD:

  1. Compulsions appear to work.
  2. The person with OCD is motivated to believe compulsions work.

Compulsions seem to work

According to research, those with OCD—compared to other individuals—feel less in control and/or desire more control

One way people with OCD try to gain control is by performing compulsions.

For example, if an individual has obsessive thoughts about someone breaking into his home when he is asleep, he may conclude he has very little control over his safety. To feel more in control, he might try to check the locks fifty times before going to bed.

Why do compulsions appear to be effective in helping people with OCD feel more in control? To answer this question, I direct your attention to an exchange from the popular TV show, The Simpsons. Humor aside, the scene illustrates a common mistake. Like Homer, we sometimes mistake correlation (an association between two events) for causation.

We join Homer and Lisa in the middle of a conversation about safety.

Lisa: By your logic, I could claim that this rock keeps tigers away.

Homer: Oh, how does it work?

Lisa: It doesn’t work.

Homer: Uh-huh.

Lisa: It’s just a stupid rock.

Homer: Uh-huh.

Lisa: But I don’t see any tigers around, do you?

Homer (looking around, then): Lisa, I want to buy your rock.

The idea that a rock keep tigers away is a correlation: A (Lisa holding a rock) and B (there being no tigers around) are correlated. But just because A and B are true at the same time does not mean that one causes the other.

To see the relevance of correlation/causation distinction to OCD, consider someone who cleans compulsively because she fears getting ill. Her compulsions appear to work because for months she has not caught a serious illness. So A (excessive cleaning) and B (no serious illness) are correlated. Yet she is assuming one causes the other, an assumption that may be challenged if she gets ill.

People with OCD are motivated to believe compulsions work

Individuals with obsessive-compulsive disorder believe compulsions work perhaps not only because compulsions seem to work but also because people with OCD need compulsions to work. If compulsions do not work, one is back to feeling powerless, out of control, and constantly living in fear of something terrible happening. So compulsions have to work.

Let us return to our example of the woman who spends many hours doing her cleaning ritual. What happens if she gets ill? Will she give up her compulsion?

Not likely. She may come up with arguments in favor of keeping the compulsion. To illustrate, here are three such arguments:

  1. “Had I not done my cleaning ritual, I would have become more seriously ill or would have caught the illness a long time ago.”
  2. “I got ill because I did not do my ritual properly. I must have missed a spot.”
  3. “This illness is a wake-up call. I can see that my routine is not as good as it needs to be. I should spend more time cleaning.”

It is difficult to challenge these beliefs. Had this person’s beliefs been completely nonsensical, it would have been much easier to dispute them. But that is not the case; often what the person with OCD believes is possible; it is just not probable.

Concluding thoughts on compulsions

Compulsions are usually understandable but exaggerated reactions to fear; they are also related to the need for control. Compulsions waste a lot of energy and resources, and can never fully protect the person from feared events.

In my next couple of articles, I discuss an effective treatment for OCD. This treatment requires the person to stop doing her compulsion—yes, the very thing that appears to be helping manage her fears and obsessions. This may not be easy. She will have to face her fears and convince herself that the safety provided by compulsions is an illusion. I will say more about this in my next post.


1. American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Arlington, VA: Author.

2. Moulding, R., Kyrios, M. (2007). Desire for control, sense of control and obsessive-compulsive symptoms. Cognitive Therapy and Research, 31, 759–772.