[Nutrition and dietary supplements in psychiatric diseases]

Nutrition and specific nutritional supplements can have prophylactic or therapeutic properties with respect to certain psychiatric disorders. A traditional Mediterranean diet, for example, seems to have prophylactic benefits against depression and dementia, whereas overeating and obesity increase the risk for both.Although evidence for nutritional supplements in the treatment of psychiatric disorders is not sufficient for general recommendations, data from observational studies and randomized controlled trials (RCT) seem to point to their use for specific indications. Folate, S-adenosylmethionine (SAM) and eicosapentaenoic acid (EPA), for instance, seem to have antidepressant properties, zinc may be beneficial in attention deficit hyperactivity disorder (ADHD), vitamin B6 (pyridoxine) could reduce extrapyramidal side effects of antipsychotics and N-acetylcysteine (NAC) seems to be effective against negative symptoms, abnormal movements and akathisia in schizophrenia.Psychiatric disorders, in turn, may lead to deficiency of mineral nutrients and vitamins. For instance, vitamin B1 (thiamine) deficiency is common in alcohol-dependent patients and should therefore be considered during withdrawal treatment. Although vitamin malnutrition is uncommon in developed countries, vitamin deficiency syndromes, such as pernicious anemia or Wernicke's encephalopathy are still relevant differential diagnoses.Some psychopharmacological drugs may additionally change the nutritional habits of the patients in an unfavorable way leading to weight gain and obesity and the risk for further psychiatric problems.