Effects of vitamins, minerals and other dietary supplements on mental health in people with schizophrenia

Key message

Schizophrenia is a serious mental illness. Schizophrenia may be chronic, but partial or complete recovery is possible. The mainstay of treatment for schizophrenia is pharmacological. Vitamins, minerals and other dietary supplements are sometimes used as adjunct therapy, but the effect of such treatment is uncertain.

This review was commissioned by the Health Directorate in June 2010 as part of a larger commission from 2009. The Knowledge Centre was asked to complete a review that could help elucidate the effects of vitamins, minerals and other dietary supplements on mental health in people with schizophrenia.

We included seven systematic reviews of high and moderate methodological quality. The reviews covered the effects of ayurvedic medicine, polyunsaturated fatty acids, and Chinese herbal medicines such as ginkgo. The results of these systematic reviews could be summarized in four main findings:   

• Results do not suggest ayurvedic medicine is more effective than antipsychotics on mental health in people with schizophrenia.  
• Given the limited knowledge base it is unclear to what extent polyunsaturated fatty acids, such as omega-3, as adjunct treatment with antipsychotics are more effective than antipsychotics alone on mental health in people with schizophrenia.  
• It is possible that gingko (a type of Chinese herbal medicine) as adjunct treatment with antipsychotics is more effective than antipsychotics alone in reducing symptoms in people with schizophrenia.
• We did not identify any systematic reviews about the effectiveness of vitamins and minerals on mental health in people with schizophrenia. Our literature search did not include a search for primary studies, and it is possible that methodologically sound primary studies on this topic exist.