Social and physical anhedonia in relation to cerebral laterality and electrodermal habituation in unmedicated psychotic patients.

The neglect of psychophysiological investigation of social anhedonia, in contrast to physical anhedonia, was addressed by examining relations between electrodermal orienting responses and their lateral asymmetry in unmedicated schizophrenic, bipolar/schizoaffective, and unipolar depressive patients and normal control subjects. In support of relations between social withdrawal and right-hemispheric reactivity, social anhedonia was associated with a predominance of right-hemispheric influences in schizophrenic and bipolar/schizoaffective patients but not in depressive patients. Anhedonia in all but the depressive group was also related to responsiveness, particularly when fast habituators were pooled with nonresponders and compared with moderate and slow habituators. Anhedonia was higher in the more responsive group. This was particularly true of physical anhedonia. The results support associations between both types of anhedonia--social and physical--and psychophysiology, and they also suggest that anhedonia is not a unitary concept.