Obsessive-compulsive disorder (OCD) is characterized by sudden, recurrent, upsetting thoughts or images that intrude into consciousness (obsessions) and/or rule-governed acts that the person feels driven to perform. OCD is a prevalent life-long condition that frequently is associated with marked impairment and disability. Historically, a vast array of treatments has been tried in OCD with variable success. Although clinical care has improved, a significant number of patients fail to respond adequately to either cognitive-behavioral or pharmacological treatments or they experience troublesome side effects. A long-term objective of many research programs is the safe and effective treatment of OCD and related disorders. However, the effectiveness of these interventions depends largely on the extent and quality of our knowledge base. It is essential that we understand the natural history of these disorders over the course of development (from childhood onset through adolescence and into adulthood) and the patho-physiological mechanisms that mediate symptom expression in vulnerable individuals. We expect that this information will extend to an understanding at the molecular level of how specific genetic factors confer vulnerability, as well as how developmental changes in the hormonal and neurochemical microenvironment influence the course of these disorders.
Symptom Profile and Phenomenology
OCD is characterized by either obsessions (recurrent and persistent ideas, thoughts, or images) or compulsions (repetitive behaviors performed according to certain rules or in a stereotyped fashion; American Psychiatric Association, 1994). In addition, these obsessions or compulsions cause marked distress or significantly interfere with the patient's function. Symptomatically, both compulsivity and impulsivity have in common the inability to inhibit or delay repetitive behaviors. The difference between the two lies in the driving foci. In compulsivity, it is the need to decrease the discomfort associated with rituals, and in impulsivity, it is the need for the maximization of pleasure. It should also be noted, however, that not all compulsions reduce anxiety.
