13.4 Obsessive-Compulsive Disorder

At age 12, Melissa was diagnosed with obsessive-compulsive disorder (OCD), a psychological disorder characterized by unwanted thoughts, or obsessions, and repetitive, ritualistic behaviors known as compulsions.

An obsession is a thought, urge, or image that occurs repeatedly, is intrusive and unwelcome, and often causes feelings of intense anxiety and distress. Melissa’s recurrent, all-consuming thoughts of disaster and death are examples of obsessions. People with obsessions stop these unwanted thoughts and urges, or at least ignore them, often attempting to “neutralize” them with a replacement thought or activity. This isn’t always helpful, though, because the replacement can become a compulsion, which is a behavior or “mental act” repeated over and over.

For Melissa, these compulsions eventually took over her life. In the morning, for example, she would reapply deodorant and put her clothes on and take them off up to 20 times—because if she failed to execute these procedures just right, she believed something dreadful was bound to happen. On September 11, 2001, when terrorists attacked New York City and Washington, D.C., Melissa blamed herself because she had put on her blouse an odd, rather than even, number of times that day.

People with OCD experience various types of obsessions and compulsions. In many cases, obsessions focus on fears of contamination with germs or dirt, and compulsions revolve around cleaning and sterilizing (Cisler, Brady, Olatunji, & Lohr, 2010). One such OCD sufferer reported washing her hands until her knuckles bled, living in fear that she would kill someone with her germs (Turk, Marks, & Horder, 1990). Other common compulsions include repetitive rituals and checking behaviors. Melissa, for example, developed a compulsion about locking her car. After parking on the street, she would do what any street-smart person does—lock the doors. But unlike most people who lock their cars once and walk away, Melissa felt compelled to lock it twice. Then she would begin to wonder whether the car was really locked, so she would lock it a third time—just in case. But 3 is an odd number, and odd numbers just don’t sit well with Melissa, so she would lock it a fourth time. Yet that didn’t feel quite right either. By the time Melissa finally felt sufficiently comfortable to walk away, she had locked her car eight times. And sometimes that was still not enough.

How do you explain this type of behavior? OCD compulsions often aim to thwart unwanted situations, and thereby reduce anxiety and distress. Melissa was tormented by multiple obsessions ranging from catastrophic (the death of her mother) to minor (someone stealing her iPod). But the compulsive behaviors of OCD are either “clearly excessive” or not logically related to the event or situation the person is trying to prevent (APA, 2013).

Where do we draw the line between obsessive or compulsive behavior and the diagnosis of a disorder? Remember, behaviors or symptoms must be significantly distressing or disabling in order to be considered abnormal and qualify as a disorder. This is certainly the case with OCD, in which obsessions and/or compulsions are very time-consuming (taking more than 1 hour a day) and cause a great deal of distress and disruption in daily life. Everyone has odd thoughts and quirky routines, but they don’t eat up multiple hours of the day and interfere with school, work, and relationships. That’s the key distinction between normal preoccupations and OCD (APA, 2013).

Evidence suggests that the symptoms of OCD are related to abnormal activity of neurotransmitters. Reduced activity of serotonin is thought to play a role, though other neurotransmitters are also being studied (Bloch, McGuire, Landeros-Weisenberger, Leckman, & Pittenger, 2010). Certain areas of the brain have also been implicated, including locations in the basal ganglia, cingulate gyri, and orbital frontal cortex (APA, 2013; Radua & Mataix-Cols, 2009). These regions play a role in planning and regulating movement (Rotge et al., 2009).

Why do these biological differences arise? There appears to be a genetic basis for OCD. If a first-degree relative (parent, sibling, or offspring who shares about 50% of one’s DNA) has an OCD diagnosis, the risk of developing OCD is twice as high as someone whose first-degree relatives do not have the disorder (APA, 2013).

To ease her anxiety, Melissa turned to compulsions—repetitive, ritualistic behaviors aimed at relieving or offsetting her obsessions. Because her greatest fears never came to pass, Melissa assumed that her actions had prevented them. I didn’t die because I touched all the things in my room just the right way, she would think to herself. The more she followed through on her compulsions and saw that her fears never played out, the more convinced she became that her behaviors prevented them. As Melissa put it, “When you feed it, feed it, feed it, it gets stronger.”

Here, we see how learning can play a role in OCD. Melissa’s compulsions were negatively reinforced by the reduction in her fear. The negative reinforcement led to more compulsive behaviors, those compulsions were negatively reinforced, and so on. As you can see, this learning process is ongoing and potentially very powerful. In one study, researchers monitored 144 people with OCD diagnoses for more than 40 years. The participants’ OCD symptoms improved, but almost half continued to show “clinically relevant” symptoms after four decades (Skoog & Skoog, 1999).