Impaired fear recognition in regular recreational cocaine users

The ability to read facial expressions is essential for normal human social interaction. The aim of the present study was to conduct the first investigation of facial expression recognition performance in recreational cocaine users.

Three groups, comprised of 21 cocaine naïve participants (CN), 30 occasional cocaine (OC), and 48 regular recreational cocaine (RC) users, were compared. An emotional facial expression (EFE) task consisting of a male and female face expressing six basic emotions (happiness, surprise, sadness, anger, fear, and disgust) was administered. Mean percent accuracy and latencies for correct responses across eight presentations of each basic emotion were derived. Participants were also assessed with the "Eyes task" to investigate their ability to recognize more complex emotional states and the Symptom CheckList-90-Revised to measure psychopathology.

There were no group differences in psychopathology or "eyes task" performance, but the RC group, who otherwise had similar illicit substance use histories to the OC group, exhibited impaired fear recognition accuracy compared to the OC and CN groups. The RC group also correctly identified anger, fear, happiness, and surprise, more slowly than CN, but not OC participants. The OC group was slower than CN when correctly identifying disgust. The selective deficit in fear recognition accuracy manifested by the RC group cannot be explained by the subacute effects of cocaine, or ecstasy, because recent and less recent users of these drugs within this group were similarly impaired. Possible parallels between RC users and psychopaths with respect to impaired fear recognition, amygdala dysfunction, and etiology are discussed.