An open-label trial of St. John's Wort (Hypericum perforatum) in obsessive-compulsive disorder

Recent interest in and evidence for the efficacy of St. John's wort (Hypericum perforatum) for the treatment of mild-to-moderate depression has led to speculation about its efficacy in other disorders. Hypericum's mechanism of action is postulated to be via inhibition of the synaptosomal uptake of serotonin. As such, there is a suggestion that Hypericum may be effective for obsessive-compulsive disorder (OCD).

Twelve subjects were evaluated with a primary DSM-IV diagnosis of OCD of at least 12 months' duration. Treatment lasted for 12 weeks, with a fixed dose of 450 mg of 0.3% hypericin (a psychoactive compound in Hypericum) twice daily (extended-release formulation). Weekly evaluations were conducted with the Yale-Brown Obsessive Compulsive Scale (Y-BOCS), the Patient Global Impressions of Improvement Scale, and the Clinical Global Impressions of Improvement scale (CGI) and monthly evaluation with the Hamilton Rating Scale for Depression.

A significant change from baseline to endpoint was found, with a mean Y-BOCS change of 7.4 points (p = .001). Significant change occurred at 1 week (p = .020) and continued to increase throughout the trial. At endpoint, 5 (42%) of 12 were rated "much" or "very much improved" on the clinician-rated CGI, 6 (50%) were "minimally improved," and 1 (8%) had "no change." The most common side effects reported were diarrhea (N = 3) and restless sleep (N = 2).

Significant improvement was found with Hypericum, with a drop-in Y-BOCS score similar to that found in clinical trials. The fact that a significant change was found as early as 1 week into treatment suggests a possible initial placebo response, although improvement grew larger over time. Results warrant a placebo-controlled study of Hypericum in OCD.