Negative affect heightens opiate withdrawal-induced hyperalgesia in heroin dependent individuals.

This study examined the effect of emotion on opiate withdrawal induced hyperalgesia to determine whether emotional states modulate the magnitude of hyperalgesia. One hundred Hispanic men were recruited into one of three groups: heroin withdrawal, long-term heroin abstinence, and control. Participants were presented with pictures to induce neutral, positive, and negative emotional states. Affective valence, arousal, pain threshold, and tolerance to ischemic pain were measured. When pain threshold and tolerance were compared, the withdrawal group displayed significant heightened pain sensitivity when negative affect was induced. The authors also found that former heroin addicts showed heightened pain sensitivity following months of abstinence.