Abnormal Psychology

302 CHAPTER 7

Understanding Obsessive-Compulsive Disorder

OCD can be understood by considering neuropsychosocial factors and their in-

teractions. As with social phobia, neurological, psychological, and social factors

infl uence one another. With OCD, however, social factors have less infl uence

than neurological and psychological factors do. Howard Hughes had neuro-

logical and psychological vulnerabilities for the disorder that may have been

exacerbated by psychological and social factors. Let’s exam-

ine these factors in more detail.

Neurological Factors

Researchers have made much progress in understanding the

neurological under pinnings of OCD. In the following sec-

tions we’ll review how brain circuits have gone awry in this

disorder, resulting in a loop of neural activity that may pro-

duce intrusive thoughts (obsessions) and lead one to repeat

the same behavior over and over (compulsions); we’ll also see

that abnormalities in how neurotransmitters function (sero-

tonin) play a role in this disorder. However, although genes

also play a role, the genetic story is complex: Genes predis-

pose people toward developing this disorder, but apparently

by having an effect on anxiety disorders in general—not OCD

in particular.

Brain Systems

When the frontal lobes trigger an action, there is feedback

from the basal ganglia—and sometimes this feedback sets up

a loop of repetitive activity, as shown in Figure 7.14 (Breiter

et al., 1996; Jenike, 1984; Rauch et al., 1994, 2001). Many

researchers now believe that this neural loop plays a key role

in obsessive thoughts, which intrude and cannot be stopped

easily. Performing a compulsion might temporarily stop the

obsessive thoughts by reducing the repetitive neural activity

(Insel, 1992; Jenike, 1984; Modell et al., 1989). (But soon

after the compulsive behavior stops, the obsessions typically

resume.)

Consistent with these ideas, Rapoport (1991) proposed

that OCD symptoms can be caused by dysfunctional connec-

tions among the frontal lobes, the thalamus, and the basal

ganglia (see Figure 7.14). Much research has focused on

possible abnormalities in the basal ganglia and frontal lobes

Table 7.15 • Obsessive-Compulsive Disorder

Facts at a Glance

Prevalence

• Approximately 2– 3% of Americans will develop OCD at some point in
  their lives (Burke & Regier, 1994), with generally similar prevalence rates
  worldwide (Horwath & Weissman, 2000).

Comorbidity

• Over 90% of those with OCD have another Axis I disorder, with the
  most frequent categories of comorbid disorders being mood disor-
  ders (81%) and other anxiety disorders (53%) (LaSalle et al., 2004).
  Eating disorders and some personality disorders are also relatively
  commonly diagnosed as comorbid with OCD.

Onset

• Among males with OCD, symptoms typically begin to emerge between
  the ages of 6 and 15.


• Among females, symptoms typically emerge between the ages of 20
  and 29.

Course

• Symptoms typically build gradually until they reach a level that meets
  the diagnostic criteria. Over the course of a lifetime, symptoms wax and
  wane, becoming particularly evident in response to stress.

Gender Differences

• Men and women have an equal risk of developing OCD.

Cultural Differences

• Although the prevalence rates of OCD and the types of symptoms are
  about the same across cultures, the particular content of symptoms
  may differ as a function of cultural or religious prohibitions (Matsunaga
  et al., 2007; Millet et al., 2000).
  Source: Unless otherwise noted, information in the table is from American Psychiatric
  Association, 2000.

All right, I got to the bedroom door without touching anything else, but I better step

through and out again, just to be sure nothing bad will happen. THERE, THAT WAS EASY! Now

to the bathroom. I better turn that light on, NO, off, NO, on, NO, off, NO, on, KNOCK IT OFF! All

right, I’m done using the toilet, better fl ush it. OK, now spin around, wait for the toilet to fi n-

ish a fl ush, now touch the handle, now touch the seat, remember you have to look at every

screw on the toilet seat before you turn around again. OK, now turn around and touch the seat

again, look at all the screws again. OK, now close the cover.

OK, let’s pick out some clothes in the bedroom. First, I have to get out of the bathroom. Step

in, step out, step in, step out, now look at all the hinges on the bathroom door. Do this on each

step, both in and out of the bathroom.

OK, let’s get some underwear. I want to wear the green ones because they fi t the best, but

they’re lying on top of the T-shirt my grandmother gave me, and her husband (my grand-

father) died last year, so I better wash those again before I wear them. If I wear them, some-

thing bad might happen.

(Steketee & White, 1990, pp. 4–5)