Nicotinic Acid Long-Term Effectiveness in a Patient with Bipolar Type II Disorder: A Case of Vitamin Dependency.

Nicotinic acid (NA), often called niacin, a form of vitamin B3, is a water-soluble nutrient found in animal and vegetarian foods. Vitamin B3 for healthy people is considered to be needed in doses of less than 20 mg daily. In higher doses, NA has been described to be beneficial in some patients with psychiatric disorders. This report describes a male patient with bipolar type II disorder who for many years had been treated with lithium and other medications applied in affective disorders. These pharmacological drugs had beneficial effects but were at times insufficient. When the patient was prescribed NA, he experienced a comparatively strong effect. Slowly it was discovered that the patient could lower and cease all medications except NA. For over 11 years he has been stable and calm with NA and currently takes 1 g three times daily. When not taking NA, he consistently became anxious and depressed within 2-3 days. The resumption of NA resulted in a normal state usually within 1 day. This finding has been described as a vitamin dependency. The paper discusses possible mechanisms for the effect of NA in this patient. Further studies are needed to investigate the prevalence of vitamin B3 dependency and the biochemical explanations for this phenomenon.