Obsessions and Compulsions

After Anxiety Disorders, the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, 5th Edition) continues with Obsessive-Compulsive and Related Disorders. To understand these disorders, we need to know what an obsession is—distinguishing it from other forms of repetitive thoughts—and what a compulsion is. As usual, I will try to explain this in my own words.

An obsession is a frequent and constant thought experienced as an "unwanted guest" (intrusive). The individual does not want to have this thought and tries to ignore, suppress, or neutralize it. Here are some examples of obsessions:

• Contamination obsessions: "Did I wash my hands enough?"
• Doubt obsessions: "Did I turn off the gas?", "Did I lock the car?"
• Aggressive obsessions: "Could I kill him?", "Could I kill myself?"
• Relationship obsessions: "Is he/she cheating on me?"

Very similar to an obsession, but qualitatively different, is overthinking. Rumination is again a repetitive and constant thought. A primary difference from an obsession is that people often overthink about past events (though not exclusively), perhaps replaying conversations with the goal of making them go differently. Overthinking, while annoying, is not always intrusive—sometimes people want to overthink. Additionally, overthinking is partially controllable.

A fixation is also a repetitive and constant thought, but not intrusive. "Having a fixation" is not necessarily a negative thing. Even though someone might spend a lot of time on their fixation, it does not cause distress.

Compulsions are repetitive behaviors or thoughts that the individual feels compelled to perform in response to an obsession or according to rigid and scrupulous rules. Compulsions are meant to reduce anxiety or prevent situations that cause fear (due to obsessive thoughts), but compulsions do not realistically address the fear or are clearly excessive.

Let's use an example. Suppose an individual has an obsession with contamination from germs due to contact. Washing hands repeatedly could be a compulsion that responds to the fear of contamination. But does washing hands (even thoroughly) mean there are no more germs on the hands? Realistically, no. Even washing hands a certain number of times in a row does not eliminate all germs. The compulsion, therefore, does not address the fear that is the core of the obsession.

The diagnostic manual describes five main disorders in the category of obsessive-compulsive and related disorders:

1. Obsessive-Compulsive Disorder (OCD)
2. Body Dysmorphic Disorder (BDD)
3. Hoarding Disorder
4. Trichotillomania (Hair-Pulling Disorder)
5. Excoriation (Skin-Picking) Disorder.

Sources:

• American Psychiatric Association (2013) - Diagnostic and Statistical Manual of Mental Disorders (5th ed.).
• Bernhill, J. W. (2014) - DSM-5 Clinical Cases.

If you want me to describe a psychology topic in my own words, please write it in the comments.