Tehran University of Medical Sciences Iranian Journal of Psychiatry 1735-4587 1 2 2006 06 15 54 58 Firoozeh Raisi Psychiatry and Psychology Research Center, Roozbeh Hospital, Tehran University of Medical Sciences, Tehran, Iran Department of Psychiatry, Roozbeh Hospital, Tehran University of Medical Sciences, Tehran, Iran Marzieh Tavakoli Psychiatry and Psychology Research Center, Roozbeh Hospital, Tehran University of Medical Sciences, Tehran, Iran Abbas Ali Nasehi Iran Helal Institute of Applied Science &Technology 2015 10 17 Objective: The fact that some antidepressants with strong effects on serotonin reuptake blockade fail to relieve obsessive-compulsive symptoms has caused growing interest in investigating noradrenergic function in obsessive-compulsive disorder (OCD) . In light of the above, we undertook a trial to investigate whether the combination of citalopram with nortriptyline is more effective in treating obsessive-compulsive symptoms than citalopram alone. Method: 40 patients who met the DSM-IV criteria for OCD were included in the study. Patients were allocated in a random fashion: 20 patients to citalopram 40mg /day plus nortriptyline 50mg /day, and 20 patients to citalopram 40mg /day plus placebo. Results: Both protocols significantly decreased the scores of the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) over the trial period, but the combination of citalopram and nortriptyline showed a significant superiority over citalopram alone in the treatment of OCD. Conclusion: As this study indicates, nortriptyline improves the efficacy of citalopram. In addition, a rapid onset of action is one of the advantages of this combination. This study supports further investigation of the noradrenergic– serotonergic hypothesis in OCD. https://ijps.tums.ac.ir/index.php/ijps/article/view/405 https://ijps.tums.ac.ir/index.php/ijps/article/download/405/400