People with cocaine use disorder tend to make riskier decisions than non-addicted people after losing a potential reward, according to a new study published in the journal Biological Psychiatry: Cognitive Neuroscience and Neuroimaging.
This heightened sensitivity to loss correlates with an exaggerated decrease in a part of the brain that processes rewards.
The findings suggest that altered neural processing of risk and reward drives people with cocaine addiction to take further risks to win back a lost reward. This helps researchers better understand why cocaine users tend to make risky decisions despite the potential negative outcomes.
“This paradoxical relationship between how someone acts in response to a loss can give us clues for how to develop better interventions and how to track the recovery of the brain from cocaine addiction,” said first author Dr. Joshua Gowin of the University of California, San Diego and the National Institute on Alcohol Abuse and Alcoholism in Bethesda, Maryland.
For the study, the researchers compared the behavior and studied the neuroimages of 29 participants diagnosed with cocaine use disorder and 40 healthy control participants as they performed a Risky Gains Task. During this task, the participants could earn money by choosing between three monetary values, the lowest value being the safest option and higher values being riskier.
As the potential value of the reward got higher, the control group showed a proportional increase in activity of the ventral striatum, a brain region important for processing reward. This was not observed in the cocaine use disorder group. According to the researchers, this suggests that riskier behavior in people with cocaine use disorder is not motivated by reward.
“In an interesting parallel to their real life behavior, brain activity and choice behavior during a gambling task used in this study indicate an aberrant sensitivity to loss and a tendency to double down and make risky choices,” said Cameron Carter, editor of the journal.
Significantly, both addicted and non-addicted groups of people made risky decisions at a similar frequency overall, and the effect was only observed after participants had lost a gamble in a previous round.
In addition, the researchers found that lifetime cocaine use correlates with activity of the anterior cingulate cortex during a risky decision, which suggests a direct association between neural processing of risk and substance use.
Since the study findings were observed at a single point in time after people had already developed cocaine use disorder, it remains unknown if the differences in behavior and neuroimages were present before cocaine use or were caused by it. Future studies that follow people at high risk for the disorder over time may be able to address this question.