herbal medicines in the treatment of psychiatric and neurological disorders

objective: this review will indicate the quality of the evidence supporting the clinical effects of a number of commonly used types of herbal medicines for psychiatric and neurological disorders. method: we conducted a review of literature to understand the biochemical and evidential bases for the use of herbs in psychiatric and neurological disorders as follow: 1) alzheimer’s disease, 2) depression, 3) anxiety, 4) insomnia, 5) substance use disorders, 6) attention deficit/hyperactivity disorder (adhd), 7) migraine. results: evidences support use of ginkgo biloba, huperzine a, galantamine, melissa officinalis,and salvia officinalis for alzheimer’s disease; st. john’s wort, lavender, and saffron for depression; passionflower, and kava, for anxiety disorders; valerian, and english lavender for sleep disorders; hypericum for substance related disorders; ginkgo biloba, and passionflower for adhd; and feverfew, and butterbur root for migraine. the highest level of confidence derives from well-designed, randomized, double blind controlled studies. conclusion: herbs may have beneficial effects in variety of psychiatric and neurological disorder; however we must consider their potential side effects and drug-drug interactions.