The cortical serotonin2 receptors studied with positron-emission tomography and [18F]-setoperone during depressive illness and antidepressant treatment with clomipramine

Background: Changes in serotonin (5-HT)(2) receptor densities were reported in depression by postmortem studies and following treatment with tricyclic antidepressants in animal studies. Here, 5-HT2 receptors were studied in vivo in depressed patients. Methods: Cortical 5-HT2 receptors were investigated prospectively using positron-emission tomography and [F-18]-setoperone in 7 depressed patients, before and after at least 3 weeks of clomipramine (CMI), 150 mg daily. They were compared to 7 age-matched controls, Results: There was no significant difference between the untreated patients and the controls, except in the frontal region, where the [F-18]-setoperone specific binding was slightly lower in patients. After CMI treatment depression scares significantly improved and [F-18]-setoperone specific binding decreased in cortical regions, suggesting receptor occupancy and/or receptor regulation, by CMI, however no clinical score correlated with the 5-HT2 receptor measurements either in the untreated or in the treated conditions. Conclusions: These data substantiate the view that tricyclic antidepressants such as clomipramine significantly interact with cortical 5-HT2 serotoninergic receptors in actual therapeutic situations. (C) 1999 Society of Biological Psychiatry.