Long-term sertraline treatment and peripheral biochemical markers in female depressed patients

Serotonergic system is implicated in the pathogenesis of depression. Peripheral biochemical markers, platelet serotonin (5-HT) and platelet monoamine oxidase (MAO) activity, were determined spectrofluorimetrically at baseline and after 4 and 24 weeks of sertraline (a selective serotonin reuptake inhibitor) treatment in 15 female nonsuicidal, nonpsychotic patients with major depression, and compared with 15 drug free healthy women. The aim of the study was to determine the effects of 4 and 24 weeks of sertraline treatment on platelet 5-HT concentration and platelet MAO activity in depressed patients subdivided according to the treatment response into remitters, responders and nonresponders after 4 and 24 weeks of sertraline treatment, based on the 70%, 50-69% and less than 49% reductions in baseline Montgomery-Asperg Depression Rating Scale (MADRS) scores, respectively. Platelet 5-HT concentration was significantly lower in all depressed patients at baseline than in healthy subjects. Among patients platelet 5-HT concentration or platelet MAO activity did not differ before treatment. There was no significant correlation between MADRS scores and peripheral biochemical markers. The limitation of the study was in a small number of patients, but its advantage was in a long-term (24 weeks) follow-up of both patients and healthy controls. Our results show that long-term sertraline treatment induced remission and response in 87% patients, decreased platelet 5-HT concentration after 4 and 24 weeks of treatment and decreased platelet MAO activity after 24 weeks, and suggest that pretreatment values of platelet 5-HT and platelet MAO might not predict therapeutic outcome to sertraline treatment in female depressed patients.