Regular cocaine users have difficulties in feeling empathy for others and exhibit less prosocial behaviour, scientists say.
Researchers at the Psychiatric Hospital of the University of Zurich in Switzerland found that cocaine users have social deficits because social contacts are less rewarding for them.
Chronic cocaine users display worse memory performance, concentration difficulties, and attentional deficits but also their social skills are affected as previous studies at the University of Zurich suggested.
These investigations also found that cocaine users have difficulties to take the mental perspective of others, show less emotional empathy, find it more difficult to recognise emotions from voices, behave in a less prosocial manner in social interactions, and they reported fewer social contacts.
Moreover, worse emotional empathy was correlated with a smaller social network.
The scientists now believe that social cognitive deficits contribute to the development and perpetuation of cocaine addiction.
In the new study published in the Proceedings of the National Academy of Sciences, psychologists Katrin Preller and Boris Quednow, Head of the Division of Experimental and Clinical Pharmacopsychology at the Psychiatric Hospital of the University of Zurich, concluded that impaired social interaction skills of cocaine users could be explained by a blunted response to social reward.
The research team demonstrated that cocaine users perceived joined attention - the shared attentional focus of two persons on an object after gaze contact - as less rewarding compared to drug-naive healthy controls.
In a subsequent functional imaging experiment they showed that cocaine users showed a blunted activation of a crucial part of the reward system - the so called medial orbitofrontal cortex - during this basal kind of social interaction.
A weaker activation of the medial orbitofrontal cortex during social gaze contact was also associated with fewer social contacts in the past weeks.
"Cocaine users perceive social exchange as less positive and rewarding compared to people who do not use this stimulant," Quednow said.
