Biological Mechanisms and Treatment of Obsessive-Compulsive Disorder.

This review provides an overview of biological processes that contribute to obsessive-compulsive disorder (OCD). It encourages nonreductionist integration of biological findings with psychological and social constructs. OCD runs in families; studies are beginning to identify genetic variants that contribute to risk, though these findings are not yet clinically actionable. A robust body of neuroimaging research implicates hyperactivity in certain brain circuits in the pathophysiology of OCD, which often normalizes following successful treatment. The efficacy of serotonin reuptake inhibitors is well-established; however, evidence does not support a simple serotonin deficit model. The role of the neurotransmitter glutamate in pathophysiology and treatment is under investigation. Emerging research is exploring the contributions of immune system dysregulation and of hormones to pathophysiology. Pharmacological treatment strategies are reviewed, as are anatomically targeted interventions for refractory cases. Future treatments will likely synergistically deploy somatic and psychotherapeutic interventions, leveraging biological tools to enhance mechanisms of psychological change.