Therapeutic effects of escitalopram and reboxetine in seasonal affective disorder: a pooled analysis.

The monoaminergic neurotransmitters serotonin and noradrenaline have both been implicated in the pathogenesis of seasonal affective disorder (SAD). However, the differential therapeutic value of selective serotonin reuptake inhibitors (SSRI) and selective noradrenaline reuptake inhibitors (NARI) in SAD has not been assessed until now. This study compares data from two open-label trials with similar methodology investigating the SSRI escitalopram and the NARI reboxetine. 20 SAD patients were treated with escitalopram (10-20mg) and 15 patients received treatment with reboxetine (fixed dosage: 8mg) over 6 weeks. Ratings included the structured interview guide for the Hamilton depression rating scale, SAD version (SIGH-SAD), the clinical global impression of severity (CGI-S) and improvement (CGI-I) and the UKU side effect rating scale. Treatment led to a significant reduction in SIGH-SAD score, CGI-S and CGI-I after one week in the reboxetine group and after two weeks in the escitalopram group. SIGH-SAD score was significantly lower in the reboxetine group at weeks 1, 2 and 4 but not at the end of the study. The response rate (SIGH-SAD <50% of baseline value) and the remission rate (SIGH-SAD <8) were not significantly different after 6 weeks of treatment, but the time to response and to remission was significantly shorter in the reboxetine group. The number and severity of side effects were higher in patients treated with reboxetine at all time points. Thus escitalopram and reboxetine were equally effective in treating SAD on all primary and secondary outcome measures. Reboxetine displayed a faster onset of action, but was associated with more pronounced side effects. Further studies comparing SSRI and NARI in SAD are warranted.