Expressed emotion and auditory evoked potentials.

The expressed emotion (EE) of key relatives has been shown to predict the course of illness in psychiatric patients. In this study, we examined whether there might be physiological correlates to the EE index in nonbiological key relatives of patients with affective psychoses. High-EE and low-EE relatives were compared concerning their slopes of the amplitude/stimulus intensity function (auditory evoked N1/P2-component). We found that the slopes were clearly steeper in the case of low-EE relatives. In comparing the slopes of all key relatives with those of an age-matched control group without psychiatrically ill partners, we could find no differences. Therefore, the slope differences between high-EE and low-EE relatives do not seem to reflect differences in the illness of partners. We speculated whether a steep slope as well as low EE could be associated with an action-oriented, impulsive communication style, which would prevent the development of an affectively tense communication pattern.