Tic-related versus non-tic-related obsessive-compulsive disorder

Obsessive-compulsive disorder (OeD) 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 (compulsions; American Psychiatric Association, 1994). OeD is a prevalent life-long condition that frequently is associated with marked impairment and disability. Historically, a vast array of treatments have been tried in OeD 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 OeD 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 pathophysiological 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.