Serotonergic functioning correlates with positive and negative aect in psychiatrically healthy males

A large animal literature implicates serotonin (5-HT) in the modulation of positive and negative a€ective behavior. In contrast, data from human studies almost exclusively emphasize 5-HT modulation of negative emotional processing. However, no previous studies have directly assessed the relation between 5-HT functioning and positive (PA) and negative (NA) a€ect. The present investigation tested whether individual di€erences in 5-HT functioning correlate with PA and NA ratings in a group of healthy subjects. Thirtyone psychiatrically healthy males completed separate assessments of a€ect and 5-HT functioning. A€ect was examined with the Positive and Negative A€ect Schedule rated three times a day for two work-weeks. 5-HT functioning was indexed by the maximum prolactin response to d,l-fen ̄uramine. The prolactin response to d,l-fen ̄uramine demonstrated a signi®cant inverse correlation with mean ratings of both PA (r=ÿ0.49; p<0.005) and NA (r=ÿ0.42; p<0.05). These data provide evidence that 5-HT exerts an inhibitory in ̄uence over both PA and NA in humans, such that individual di€erences in 5-HT functioning inversely correlate with ratings of a€ect. # 2000 Elsevier Science Ltd. All rights reserved.