Erythrocyte cation transport in endogenous depression: clinical and psychophysiological correlates

Clinical (psychometric), psychophysiological and biochemical (erythrocyte membrane transport) variables were studied in 44 patients with endogenous depression (unipolar/bipolar) during acute depressive episode and in remission. All parameters studied showed paralleled and unidirectional changes when depression was compared with remission period. During a depressive episode, unipolar patients had greater intensity of depression than bipolar patients. Ouabain-dependent sodium fluxes were significantly lower in female than in male patients during depression than in remission. In male bipolar patients, the indexes of active transport in erythrocytes showed significant correlations with clinical ratings and with results of psychophysiological tests. The results point to a possible relationship between various levels of physiological functioning in endogenous depression. This suggests a generalised "background" defect of energy-dependent membrane transport pertaining to both erythrocytes and nerve cells, which may be linked to disturbances of activational processes within the central nervous system.