Decreased activity of erythrocyte membrane ATPases in depression and schizophrenia.

Erythrocyte ATP-ase activities were determined in 32 drug-free patients with depression in the course of affective illness, during acute episode, in 24 drug-free patients with schizophrenia, during exacerbation of the illness, and in 25 healthy control subjects. In both depression and schizophrenia, the activities of all three ATP-ases studied (Na-K ATPase, Mg ATPase, Ca-Mg ATPase) were significantly lower than in control subjects. No difference was found between patients with depression in the course of bipolar and unipolar affective illness. In patients with schizophrenia, the activity of Na-K ATPase was lower in the paranoid type of the illness. The results are discussed in the light of contemporary biochemical concepts of major psychoses.