Alcohol Use Disorder and Chronic Pain: An Overlooked Epidemic

Abstract

Alcohol use disorder (AUD) and chronic pain disorders are pervasive, multifaceted medical conditions that often co-occur. However, their comorbidity is often overlooked, despite its prevalence and clinical relevance. Individuals with AUD are more likely to experience chronic pain than the general population. Conversely, individuals with chronic pain commonly alleviate their pain with alcohol, which may escalate into AUD. This narrative review discusses the intricate relationship between AUD and chronic pain. Based on the literature available, the authors present a theoretical model explaining the reciprocal relationship between AUD and chronic pain across alcohol intoxication and withdrawal. They propose that the use of alcohol for analgesia rapidly gives way to acute tolerance, triggering the need for higher levels of alcohol consumption. Attempts at abstinence lead to alcohol withdrawal syndrome and hyperalgesia, increasing the risk of relapse. Chronic neurobiological changes lead to preoccupation with pain and cravings for alcohol, further entrenching both conditions. To stimulate research in this area, the authors review methodologies to improve the assessment of pain in AUD studies, including self-report and psychophysical methods. Further, they discuss pharmacotherapies and psychotherapies that may target both conditions, potentially improving both AUD and chronic pain outcomes simultaneously. Finally, the authors emphasize the need to manage both conditions concurrently, and encourage both the scientific community and clinicians to ensure that these intertwined conditions are not overlooked given their clinical significance.

Keywords: Alcohol; Alcohol Intoxication; Alcohol Use Disorder; Alcohol Withdrawal; Analgesics; Chronic Pain; Pain; Pain Measurement; Substance-Related and Addictive Disorders.

FIGURE 1.. The cycle of alcohol addiction and chronic pain^a

^a Acutely, during intoxication, pain threshold is initially elevated, with transient analgesia during the alcohol ascending limb and the eventual development of analgesic tolerance at the descending limb. As withdrawal develops, the pain threshold may lower, potentially intensifying the experience of pain. This, in turn, may lead to an increased preoccupation with alcohol as a means to alleviate pain.

FIGURE 2.. Convergent neuroadaptations produced by co-occurring alcohol addiction and chronic pain over time^a

^a Neuroadaptive changes result from repeated cycles of alcohol intoxication and withdrawal and chronic pain. Individuals with alcohol addiction experience escalating cravings and withdrawal symptoms over time. Concurrently, increased activity occurs in ascending nociceptive pathways that enhance bottom-up pain facilitation while the descending inhibitory pathways responsible for top-down pain modulation are also influenced, potentially disrupting their normal function. Attention and salience system dysfunction may contribute to pain and maladaptive patterns of alcohol use by increasing the salience of alcohol- and pain-related cues and reinforcing the cycle of pain and addiction.

FIGURE 3.. Future directions for understanding and treating alcohol addiction and chronic pain^a

^a Three synergistic future strategies for comprehending and addressing alcohol use disorder and chronic pain.