Measuring Alcohol-Induced Striatal Dopamine Release in Healthy Humans With [11C]-Raclopride: A Meta-Analysis.

Alcohol consumption is known to affect dopamine (DA) release in the brain, with significant implications for understanding addiction and its neurobiological underpinnings. This meta-analysis examined the effects of acute alcohol administration on striatal DA release in healthy humans as measured with [¹¹C]-raclopride positron emission tomography (PET). Oral alcohol administration was associated with a significant reduction in [¹¹C]-raclopride binding potential (BP_ND) in the ventral striatum (Cohen's d = -0.76), indicative of increased DA release, particularly at lower blood alcohol concentration (BAC) levels (0.08 gm%; Z = 2.34, p = 0.02). That oral alcohol may increase DA release in the ventral striatum at lower doses, and decrease DA release at higher doses, warrants further investigation but appears consistent with other known biphasic, hermetic dose-response effects of alcohol. Additionally, larger effect-sizes in the ventral striatum were observed among those studies which sampled more males than females (Z = -2.08, p = 0.04). While oral alcohol administration was associated with reduced [¹¹C]-raclopride BP_ND in the caudate (Cohen's d = -0.39) and putamen (Cohen's d = -0.37), these findings in the dorsal striatum were more variable and less robust. Our analyses suggests that study design (i.e., counterbalanced versus fixed order) may moderate effect sizes observed in the putamen across studies (Z = -2.27, p = 0.02). By identifying gaps in the current literature and proposing directions for future research, this study hopes to inform the design of future PET studies aimed at quantifying alcohol-induced dopamine release in the striatum of humans.