Electrodermal activity in young adults at genetic risk for affective disorder.

Low electrodermal activity has been proposed as a trait marker for affective disorder. We attempted to determine if low electrodermal activity could be a genetic marker by testing subjects at genetic risk for affective disorder. High-risk subjects, 22 offspring of a parent with bipolar affective disorder, and 27 low-risk controls 15 to 25 years old had skin conductance recorded bilaterally during rest periods, presentation of 10 nonsignal tones, and performance of reaction-time and mental arithmetic tasks. There were no significant differences in skin conductance levels under any condition or in the frequency or amplitude of orienting responses to nonsignal tones. During task periods high-risk subjects showed significantly greater electrodermal activity that was lateralized to the left hand. Self-rated depression was higher in the high-risk group during task periods. The results show that low electrodermal activity is not a likely genetic marker for affective disorder but suggest that autonomic hyperresponsivity, atypically lateralized information processing, and depressive affect occur during mild stress in persons at risk for the development of affective disorder.