A study in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging reports that individuals with a family history of alcohol use disorder (AUD) release more dopamine in the brain's main reward centre in response to the expectation of alcohol than people diagnosed with the disorder, or healthy people without any family history of AUD.
The study included 34 healthy participants with no family history of AUD, 16 healthy participants with a family history of the disorder (referred to as the family-history positive, or FHP, group), and 15 participants diagnosed with AUD. PET brain scanning was used to measure the amount of dopamine released in areas of the brain important for reward and addiction. Brain scans were carried out after receiving either an alcohol drink or a placebo drink. The participants didn't know the order in which they would receive the drinks.
All three groups had similar dopamine releaselevels in response to the alcohol, suggesting that alcohol-induced dopamine release is normal in AUD. However, the FHP participants had a much more pronounced response to the placebo drink than the other groups, indicating that expectation of alcohol caused the FHP group to release more reward center dopamine. The release of dopamine into the reward center is thought to reinforce alcohol consumption and possibly contribute to risk of AUD.
"This exaggerated reward centre stimulation by expectation of alcohol may put the [individuals with family history] at greater risk of alcohol use disorder, and could be a risk factor in itself," said first author Lawrence Kegeles, MD, PhD, of Columbia University. The authors state that further research is need to investigate whether an exaggerated dopamine response predicts a higher risk for the development of AUD.
Source: Enhanced Striatal Dopamine Release to Expectation of Alcohol: A Potential Risk Factor for Alcohol Use Disorder. LS. Kegeles, G Horga, Rl Ghazzaoui, R Rosengard, N Ojeil, X Xu, M Slifstein, I Petrakis, S S. O’Malley, JH. Krystal, A Abi-Dargham. Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, 2018; DOI:10.1016/j.bpsc.2018.03.018