Niacin-respondent subset of schizophrenia – a therapeutic review.

It is well known that niacin deficiency manifests with several psychiatric manifestations. Also historically evidence has accumulated that niacin augmentation can be used for treatment of schizophrenia. However, the etiopathological associations between niacin deficiency and schizophrenia as well as the mechanism of action of niacin in its treatment. More importantly, the subgroups of schizophrenia which will respond to niacin augmentation has never been highlighted in the literature. In this article, we review three of the mechanisms in which niacin deficiency could lead to schizophrenic symptoms: (1) Niacin deficiency neurodegeneration (2) Membrane phospholipid deficiency hypothesis and (3) Adrenochrome hypothesis. We will further move towards the clinical as well as treatment related associations as reviewed from the literature. Here, we propose a model that a subset of schizophrenia can respond to niacin augmentation therapy better than other subsets because these patients have contributions in their psychotic manifestations from the neural degeneration resulting from niacin deficiency. We present a short description of our case report which showed rapid improvement in schizophrenic psychotic symptoms subsequent to administration of niacin as an augmentation therapy. We, thus, propose that niacin deficiency is a contributory factor in schizophrenia development in some patients and symptom alleviation in these patients will benefit from niacin augmentation, especially in some particular psychotic features.