ABSTRACT
Selective serotonin (5-HT) reuptake inhibitors (SSRIs) and the tricyclic antidepressant drug clomipramine are the only agents thus far demonstrated to be effective in the treatment of obsessive-compulsive disorder (OCD; Fineberg, Bullock, Montgomery, & Montgomery, 1992). Because most of these medications belong to different chemical families and the only common property they share is their capacity to potently block the 5-HT transporter (Hyttel, 1994), it is undisputable that they exert their therapeutic effect in OCD via the 5-HT system. However, SSRIs are also effective antidepressant agents. Consequently, they must also exert their antidepressant effect via the 5-HT system. Because not all antidepressant drugs are effective in OCD but most of these have been shown to increase 5-HT neurotransmission (Blier & de Montigny, 1994), then the obvious question is what specific progressive modification of the 5-HT system do SSRIs induce that accounts for their apparently unique anti-OCD effect. If this peculiar property of SSRIs were known, an alternative treatment strategy could mimic this action by administering a pharmacological agent that would produce the same net effect on the 5-HT system (Fig. 27.1).
