The societal impact of heavy alcohol consumption and chronic pain is substantial and warrants the existing research investment into their etiology and treatment. Moreover, evidence of significant co-occurrence between these conditions offers an opportunity to examine mechanisms in the alcohol-pain connection that may inform the development of novel treatments. Consistent with NIH PA-15-026 (Mechanistic Studies of Pain and Alcohol Dependence), the goal of the proposed study is to examine several complex and potentially bidirectional relations between pain and alcohol in one overarching model, which has never been attempted in a human experimental paradigm. The primary study aims are as follows: (1) to conduct the first test of both pharmacological and expectancy effects in acute alcohol analgesia among humans; (2) to conduct the first test of pain as a proximal antecedent of urge to drink and ad lib alcohol consumption, and to test whether acute analgesic effects predict pain-induced alcohol urge/consumption; (3) to test associations between study outcomes and candidate genetic polymorphisms that have been implicated in pain-alcohol processes; and (4) to conduct exploratory analyses of gender and pain relevant cognitive-affective factors as moderators of these outcomes. Participants will include 280 moderate-to-heavy drinkers recruited from the local community. Experimental methods will include alcohol administration (moderate dose vs. low dose vs. placebo vs. control) and pre/post assessment of static/dynamic pain responses (study visit 1), and capsaicin/heat pain induction (vs. no pain induction) followed by assessment of urge to drink and ad lib alcohol consumption (study visit 2). By employing a novel experimental paradigm, the study results will provide internally valid data with clear and direct implications for translating these findings to clinical applications. Itis our expectation that this work will catalyze future research and inform clinical practice by establishing an experimental platform that allows for the demonstration of causal effects, the evaluation of treatment components prior to conducting costly clinical trials, and the identification of important theory-based biopsychosocial mechanisms that can inform the development of novel integrated treatments for individuals with co-occurring pain and alcohol use disorders.