Scientists at the University of Granada have found that drug-abusers have difficulty in identifying negative emotions by their facial expression: wrath, disgust, fear and sadness.
Further, regular abuse of alcohol, cannabis and cocaine usually affects abusers' fluency and decision-making. Consuming cannabis and cocaine negatively affects work memory and reasoning. Similarly, cocaine abuse is associated to alterations in inhibition.
For the purpose of this study, researchers carried out a neuropsychological evaluation out of a total of 123 polysubstance abusers and 67 no-drug users with similar social and demographical variables (age and schooling).
The target population were individuals who consumed drugs as cocaine, cannabis, heroin, alcohol, MDMA and methamphetamine, and who were enrolled in two rehabilitation projects Proyecto Hombre and Cortijo Buenos Aires in the province of Granada.
The main author of this research was Maria Jose Fernandez Serrano -supervised by professors Miguel Perez García and Antonio Javier Verdejo García- of the Department of Personality and Psychological Treatment and Evaluation, University of Granada.
The study revealed that 70 percent of drug abusers presented some type of neuropsychological deterioration, regardless the type of substance consumed. Deterioration was registered in major degree in the working memory, and in fluency, flexibility, planning, multitask ability and interference.
Fernandez Serrano thinks that the results obtained "should be employed to develop political and social policies aimed at promoting adequate rehab programs adapted to the neuropsychological profile of drug-abusers".