Methamphetamine abusers may have more difficulty than nonabusers in responding with empathy and self-control to people who are experiencing intense emotions, according to Dr. Edythe London and colleagues at the University of California, Los Angeles. Using functional magnetic resonance imaging, the researchers compared the brain patterns of 12 recently abstinent methamphetamine abusers and 12 nonabusers while they viewed images of fearful or angry faces. Compared with the nonabusers, the abusers showed less activity in brain areas related to important socioemotional processes such as interpreting facial expressions, controlling aggressive impulses, and building a concept of another person. The abusers showed greater activity than the others, however, in a region involved in pain processing and social distress. The deficit in socioemotional processing combined with the heightened signaling of negative feelings may contribute to socially inappropriate behaviors among methamphetamine abusers, the researchers say.
Drug and Alcohol Dependence 93(1-2):93-102, 2008. [Abstract]