Impairments of facial emotion recognition and theory of mind in methamphetamine abusers

Chronic use of methamphetamine is related to behavioral disturbances including depression, aggressive behavior, and social isolation. These alterations of social behavior may be attributable to impairments in social cognition. However, few studies have evaluated social cognition in methamphetamine (MA) abusers. Therefore, the aim of the present study was to investigate whether MA abusers exhibit social cognition deficits in terms of facial emotion recognition and theory of mind (ToM). We also assessed cognitive flexibility by using the Wisconsin Card Sorting Test (WCST) to evaluate the impact of this function on social cognition. Twenty-eight MA abusers and twenty-seven healthy subjects enrolled in this study. All participants performed the Facial Emotion Recognition Task and advanced ToM tasks such as the Eye Test and Hinting Task. The Korean Wechsler Adult Intelligence Scale-Revised and computerized versions of the WCST were also administrated. The performances of MA abusers on the Facial Emotion Recognition Task and Eyes Test were lower than those of healthy subjects. In the WCST, MA abusers completed significantly fewer categories and made more total and perseverative errors than healthy subjects did. In addition, impairments in cognitive flexibility are correlated with impairments in facial emotion recognition and ToM within MA abusers. These findings lend further support to the assertion that the capacity to identify emotions from facial expression and infer mental state of others is impaired in MA abusers. Therefore, treatment and rehabilitation for MA abusers must consider role of social cognition and include relearning social interactions and behaviors.