Altered Reward Processing in Abstinent Dependent Cannabis Users: Social Context Matters
Kaeli Zimmermann, Keith M. Kendrick, Dirk Scheele, Wolfgang Dau, Markus Banger, Wolfgang Maier, Bernd Weber, Yina Ma, René Hurlemann, Benjamin Becker
Study at a glance
AI-extracted from the abstract| Characteristics | Case-control study |
|---|---|
| Sample size | 47 |
| Population | Abstinent cannabis-dependent men and matched non-using controls |
| Topics | Cannabis |
| Key findings | Cannabis-dependent men showed attenuated reward experience and opposite striatal activation patterns (decreased rather than increased activation) compared to controls during female versus male social touch, with stronger alterations associated with higher lifetime cannabis exposure. |
Abstract
ABSTRACT Public perception of cannabis as relatively harmless, alongside claimed medical benefits, have led to moves towards its legalization. Yet, long-term consequences of cannabis dependence, and whether they differ qualitatively from other drugs, are still poorly understood. A key feature of addictive drugs is that chronic use leads to adaptations in reward processing, blunting responsivity to the substance itself and other rewarding stimuli. Against this background, the present study investigated whether cannabis dependence is associated with reductions in hedonic representations by measuring behavioral and neural responses to social reward in 23 abstinent cannabis-dependent men and 24 matched non-using controls. In an interpersonal pleasant touch fMRI paradigm, participants were led to believe they were in physical closeness of or touched (CLOSE, TOUCH) by either a male or female experimenter (MALE, FEMALE), allowing the assessment of touch- and social context-dependent (i.e. female compared to male social interaction) reward dynamics. Upon female compared to male touch, dependent cannabis users displayed a significantly attenuated increase of reward experience compared to healthy controls. Controls responded to female as compared to male interaction with increased striatal activation whereas cannabis users displayed the opposite activation pattern, with stronger alterations being associated with a higher lifetime exposure to cannabis. Neural processing of pleasant touch in dependent cannabis users remained intact. These findings demonstrate that cannabis dependence in men is linked to similar lasting neuroadaptations in striatal responsivity to hedonic stimuli as observed for other drugs of abuse. However, reward processing deficits seem to depend on the social context.