Comparative efficacy and tolerability among different selective serotonin re-uptake inhibitors and venlafaxine in a naturalistic setting.

The objective of this study was to compare, in a naturalistic setting, the efficacy and tolerability of currently available Selective Serotonin Reuptake Inhibitors (SSRIs) and venlafaxine in outpatients at a primary psychiatric care centre in Spain. The sample was composed of 194 patients with mood disorders (major depressive disorder or dysthymic disorder according to the DSM-TV criteria) who began treatment either with an SSRI (fluoxetine, fluvoxamine, paroxetine, sertraline, and citalopram) or with venlafaxine. Baseline severity of the mood disorder was assessed using the Hamilton Depression Rating Scale and State-Trait Anxiety Inventory, and therapeutic response was measured with the Clinical Global Impression for Therapeutic Improvement. Tolerability was assessed by recording spontaneously reported adverse experiences. There were no significant differences in the efficacy of the antidepressants under study, but there were differences in the incidence and profiles of adverse events. Fluoxetine was associated with the lowest incidence of adverse effects, in a logistical regression model, but particular events seemed to be associated with certain treatments: gastrointestinal discomfort (fluvoxamine), tremor (sertraline), dry mouth and dizziness (venlafaxine) and sweating and nervousness (citalopram). We conclude that in clinical practice there are differences in the tolerability of these antidepressants. Studies with bigger samples are needed to confirm these findings.