Worsening of obsessive-compulsive symptoms under methadone tapering.

There is data supporting the hypothesis that the endogenous opioid system may play a role in the pathophysiology of Obsessive Compulsive Disorder (OCD). The authors report a case of worsening of OCD during methadone tapering, which seems to confirm the role of the opioid system in the pathophysiology of OCD. The possible involvement of the cortico–limbic–basal–ganglia–thalamic circuit in the observed phenomenon is discussed.