Altered striatal reward processing in abstinent dependent cannabis users: Social context matters

Area of Science:

• Neuroscience
• Addiction Research
• Psychiatry

Background:

• Cannabis legalization is increasing, but long-term effects of cannabis dependence remain unclear.
• Addictive drugs typically alter striatal reward processing, affecting responses to both the drug and natural rewards.
• Understanding these changes is crucial for public health and addiction treatment.

Purpose of the Study:

• To investigate lasting behavioral and neural changes in social reward processing in abstinent cannabis-dependent men.
• To compare these responses with matched non-using controls using functional magnetic resonance imaging (fMRI).

Main Methods:

• Utilized an interpersonal pleasant touch fMRI paradigm involving male and female experimenters.
• Assessed subjective pleasantness ratings and neural activation patterns during social interactions.
• Correlated findings with lifetime cannabis exposure.

Main Results:

• Cannabis-dependent individuals reported less pleasantness from female touch compared to male touch, unlike controls.
• Controls showed increased striatal activation to female vs. male interactions; users showed the opposite pattern.
• Stronger alterations in striatal response correlated with higher lifetime cannabis exposure.

Conclusions:

• Cannabis dependence is associated with blunted striatal processing of non-drug rewards.
• These neurobiological alterations may underlie social processing deficits observed in cannabis dependence.
• Findings highlight the need for further research into the social consequences of cannabis use disorder.