Abstract
In a study designed to explain conflicting reports of hypermagnesaemia in schizophrenia, significantly higher concentrations of plasma-magnesium were found in phenothiazine-treated schizophrenic women than in normal women of the same age. This did not apply to men. Magnesium levels were inversely related to motor activity in untreated chronic schizophrenic men in hospital as well as in patients of both sexes receiving butyrophenone or phenothiazine derivatives. The magnesium concentration fell significantly when institutionalized schizophrenic and non-schizophrenic men were placed on neuroleptic medication. It is concluded that age, sex, pharmacotherapy, and level of activity all influence the metabolism of magnesium in schizophrenic subjects.