Twenty nondepressed outpatients with DSM-III obsessive-compulsive disorder entered a 10-week placebo-controlled study of clomipramine and underwent a 1-mg dexamethasone suppression test (DST) at baseline; 11 had a repeat DST at the end of treatment. Nonsuppression was rare. When compared to 82 previously described outpatients with panic disorder studied in a similar fashion, OCD patients had postdexamethasone cortisol values that were substantially lower and more stable over time. Results within the OCD group closely resembled those from a group of never-ill controls.