Obsessive-compulsive disorder (OCD) and other disorders in the OCD spectrum (e.g., hypochondriasis, body dysmorphic disorder, and eating disorders) are regarded to have complex biological and psychosocial underpinnings.
Obsessional thinking refers to the experience of persistent, intrusive, and unwanted thoughts, which are usually recognized by the person to be irrational. Such thinking dominates the person’s attention and is associated with overwhelming anxiety.
Examples include, but are not limited to a preoccupation with one’s weight, body image, germs, dirt, or illness. Compulsions are actions that a person takes to momentarily reduce, neutralize or eliminate obsessive thought. Examples of compulsions include ritualized bodily movements, repetitive checking or re-doing things, tapping or touching objects, excessive washing or decontaminating, and magical thinking (e.g., counting rituals or excessive superstitious behavior).
With respect to eating disorders, rigid caloric intake, excessive dieting, and use of diuretics are compulsions common to anorexia. The characteristic purges associated with bulimia serve to reduce the intense anxiety experienced following the excessive consumption of food (i.e., a binge) and are compulsive in nature.