Background: The use of complementary medicines in those with mental health problems is well documented. However, their effectiveness is often not established and they may be less harmless than commonly assumed.
Aims: To review the complementary medicines routinely encountered in psychiatric practice, their effectiveness, potential adverse effects and interactions.
Method: Electronic and manual literature search on the effectiveness and safety of psychotropic complementary medicines.
Results: Potentially useful substances include ginkgo and hydergine as cognitive enhancers, passion flower and valerian as sedatives, St John's wort and s-adenosylmethionine as antidepressants, and selenium and folate to complement antidepressants. The evidence is less conclusive for the use of omega-3 fatty acids as augmentation treatment in schizophrenia, melatonin for tardive dyskinesia and 18-methoxycoronaridine, an ibogaine derivative, for the treatment of cocaine and heroin addiction.
Conclusions: Systematic clinical trials are needed to test promising substances. Meanwhile, those wishing to take psychotropic complementary medicines require appropriate advice.