Project Summary Chronic Temporomandibular Disorder (TMD) is associated debilitating pain and dysfunction of the muscles of the jaw, the temporomandibular joints, and related structures. TMD pain is highly prevalent, impacting ~5-12% of the general population and over 20% of individuals seeking treatment for alcohol use disorder. Moreover, treatments for chronic pain conditions like TMD, such as opioid analgesics, are relatively ineffective, rarely meet patients’ own criteria for successful treatment, and are associated with significant risk. Therefore, many patients seek alternative, maladaptive methods for pain relief, including self-medication with alcohol. Twenty- five percent of treatment seeking people with alcohol use disorder (AUD) report past-month pain, and 25% of chronic pain patients report heavy drinking. However, the effects of pain on alcohol consumption behavior in heavy drinkers with chronic TMD pain are poorly understood. Despite the need for empirical investigations of the effect of pain on naturalistic drinking behavior, previous work has not directly addressed this question. We address this gap in knowledge by assessing the effect of pain on the microstructure of individual drinking bouts, known as drinking topography (DT). The primary objective of this study is to determine the impact of pain on DT in community-dwelling heavy drinkers with and without chronic TMD pain both in the laboratory and in daily life using ecological momentary assessment (EMA). In the laboratory, we will use the Integrated Topography and Consumption Tracking in Virtual Reality (INTACT VR) platform to provide a highly-controlled drinking environment, increasing study rigor and reproducibility. In contrast, EMA provides high ecological validity and the ability to ascertain whether pain-related DT patterns in the laboratory are also observed in the real world. Importantly, our approach is informed by the Catastrophizing, Anxiety, Negative Urgency, and Expectancy (CANUE) model, a theoretical moderated-mediation model regarding modifiable psychosocial factors underlying pain as an antecedent for substance use. The results of this study will provide mechanistic information regarding the effect of pain on alcohol consumption in heavy drinking individuals with chronic TMD pain, as well as actionable information regarding modifiable and non-modifiable risk factors for potentially hazardous alcohol use associated with pain self-management. This knowledge will facilitate optimization of interventions to reduce alcohol-related consequences in people with chronic TMD pain. Such interventions can potentially also have indirect benefits on chronic pain given evidence that hangover and alcohol withdrawal are associated with increased pain severity.