Drug Abuse Weakens the Ability to Recognize Emotion in Facial Expressions

From very early ages children can recognize the nuances of facial expressions. Infants and toddlers quickly learn to recognize happiness, sadness, or anger in their guardian’s face. As adults, we can tune in to body language and recognize the complex feelings behind each of these expressions. But some adults have lost this natural ability to recognize emotions in the human face.

Scientists from the University of Granada have found that the effects of drug abuse are robbing abusers of the ability to recognize such common emotions as sadness, wrath, fear, and disgust in facial expressions.

Neuropsychological Deterioration in Drug Abusers

María José Fernández Serrano, lead author of the study, and a team of scientists conducted a neuropsychological evaluation of persons who used drugs such as cocaine, heroin, alcohol, cannabis, Ecstasy (MDMA), and methamphetamine. These persons were also members of the rehabilitation projects, Proyecto Hombre and Cortijo Buenos Aires, in Granada. Professors Miguel Pérez García and Antonio Javier Verdejo García of the University’s Department of Personality and Psychological Treatment and Evaluation, supervised the study.

Researchers compared 123 polysubstance abusers with 67 individuals who did not use drugs. All the individuals were of similar ages and had similar schooling. The researchers used emotional processing tests and neurocognitive evaluation to examine multiple mental tasks of the individuals in their study.

Of the 123 polysubstance abusers, 70 percent exhibited some kind of neuropsychological deterioration. Researchers noted that it didn’t matter if the individual used cocaine, heroin, alcohol, or any of the other drugs previously mentioned; any combinations or individual use of these drugs caused some harm to the brain’s cognitive abilities.

Researchers at the University of Granada discovered that the following neuropsychological abilities were most affected by the regular abuse of drugs:

A Lost Connection

Losing the ability to read someone’s expression is losing a crucial link in communicating with family, friends, and colleagues. Without any words, humans convey their myriad of emotions in the wrinkles on their forehead, angle of an eyebrow, drooping of their chin, and curve of their mouth. Without any words, they still hope that those emotions are recognized and that others would be sensitive to the emotions that they may not be able to convey verbally.

Those individuals who have abused drugs may longer be able to recognize when someone is sad or angry by facial expressions alone, and those individuals who are sad and angry may become bitter and withdrawn if the tenderness, compassion, and reconciliation they need doesn’t ever happen.

Fernández Serrano hopes that the results of their study can advance the efficacy of rehabilitation programs through political and social policies that address the neuropsychological deterioration of drug abusers.