Can winter depression be prevented by Ginkgo biloba extract? A placebo‐controlled trial

OBJECTIVE: The aim was to test the hypothesis that the Ginkgo biloba extract PN246, in tablet form (brand name Bio-Biloba), may prevent the symptoms of winter depression (WD) in patients with seasonal affective disorder (SAD). METHOD: A total of 27 SAD patients were randomized to receive double-blind placebo or Bio-Biloba for 10 weeks or until they developed symptoms of WD, starting in a symptom-free phase about 1 month before expected WD symptoms. An extended Montgomery-Asberg Depression Rating Scale was completed before and immediately after termination of medication. The patients also self-rated some key symptoms on a visual analogue scale every 2 weeks during the trial. RESULTS: There were no significant differences between the treatment groups in the number of patients who developed treatment-requiring WD, or in the development of single key symptoms during the trial. CONCLUSION: We did not find that Ginkgo biloba was able to prevent the development of the symptoms of winter depression.