Rationale and objective: Preliminary data have shown that St John's wort might possess some specific efficacy in patients with somatoform complaints. Therefore, the efficacy of the Hypericum extract LI 160 in patients with somatoform disorders should be studied in a double-blind placebo-controlled fashion.
Methods: This was a multicentre, randomised, placebo controlled, 6-week trial comparing the efficacy of LI 160 (600 mg/day) and placebo in 151 out-patients suffering from somatization disorder (ICD-10: F45.0), undifferentiated somatoform disorder (F45.1), or somatoform autonomic dysfunctions (F45.3). The primary outcome measure was the decrease of the Hamilton Anxiety Scale, subfactor somatic anxiety (HAMA-SOM), during the trial period.
Results: LI 160 was superior effective concerning the primary outcome criterion HAMA-SOM [decrease from 15.39 (SD 2.68) to 6.64 (4.32) in the Hypericum group and from 15.55 (2.94) to 11.97 (5.58) in the placebo group (statistically significant difference, P=0.001)]. This was corroborated by the result of a statistically significant superior efficacy in the outcome criteria additionally used such as Clinical Global Impression, HAMA-total score, HAMA, subscore psychic anxiety, Hamilton Depression Scale, Self-Report Symptom Inventory 90 items - revised (SCL-90-R), and SCL-90-R, subscore somatic anxiety. The efficacy of LI 160 was preserved after splitting the population in those with and those without mild depressive symptoms [corrected]. Tolerability of LI 160 was excellent.
Conclusion: The data from this trial show excellent efficacy and tolerability for LI 160 in somatoform disorders. The efficacy is independent of an existing depressive mood. This is the first study showing the efficacy of a drug in patients with somatisation disorder independent of depressive symptomatology.