Continuation and long-term maintenance treatment with Hypericum extract WS 5570 after recovery from an acute episode of moderate depression--a double-blind, randomized, placebo controlled long-term trial.

The efficacy and safety of Hypericum extract WS 5570 in preventing relapse during 6 months' continuation treatment and 12 months' long-term maintenance treatment after recovery from an episode of recurrent depression were investigated in a double-blind, placebo controlled multicenter trial. Adult out-patients with a recurrent episode of moderate major depression, a 17-item Hamilton Depression Rating Scale (HAMD) total score > or =20 and > or =3 previous episodes in 5 years participated. After 6 weeks of single-blind treatment with 3 x 300 mg/day WS 5570 patients with score < or =2 on item 'Improvement' of the Clinical Global Impressions (CGI) scale and a HAMD total score decrease > or =50% versus baseline were randomized to 3 x 300 mg/day WS 5570 or placebo for 26 weeks. 426 patients were evaluated for efficacy. Relapse rates during continuation treatment were 51/282 (18.1%) for WS 5570 and 37/144 (25.7%) for placebo. Average time to relapse was 177+/-2.8 and 163+/-4.4 days for WS 5570 and placebo, respectively (time-to-event analysis; p=0.034; alpha=0.025 one-sided). Patients treated with WS 5570 showed more favorable HAMD and Beck Depression Inventory time courses and greater over-all improvement (CGI) than those randomized to placebo. In long-term maintenance treatment a pronounced prophylactic effect of WS 5570 was observed in patients with an early onset of depression as well as in those with a high degree of chronicity. Adverse event rates under WS 5570 were comparable to placebo. WS 5570 showed a beneficial effect in preventing relapse after recovery from acute depression. Tolerability in continuation and long-term maintenance treatment was on the placebo level.