Pain in alcohol use disorder: Evaluating effects of childhood trauma, perceived stress, and psychological comorbidity

The relationship between pain and alcohol use disorder (AUD) is complex and bidirectional. The current study examines risk factors for pain in a large comprehensively phenotyped sample including individuals from across the spectrum of alcohol use and misuse. Participants (n = 1101) were drawn from the National Institute on Alcohol Abuse and Alcoholism Natural History Protocol and included treatment-seeking AUD inpatients (AUD+Tx, n = 369), individuals with AUD not seeking treatment (AUD+, n = 161), and individuals without AUD (AUD-, n = 571). General linear models were utilized to test the effects of AUD status, history of childhood trauma exposure, perceived stress, and psychological comorbidity on daily percent time in pain, as well as change in daily percent time in pain across the inpatient stay in AUD+Tx individuals. Overall, 60.2% individuals reported any pain, with a significantly higher prevalence in the AUD+Tx group (82.1%) compared to the AUD+ (56.5%) and AUD- (47.1%) groups. Daily percent time in pain was also highest in the AUD+Tx group (30.2%) and was further increased in those with a history of childhood abuse and comorbid posttraumatic stress disorder (PTSD). Years of heavy drinking and craving were also associated with increased percent time in pain in the AUD+Tx group. Percent time in pain decreased following acute withdrawal in the AUD+Tx group but plateaued around 25% just prior to discharge. Individuals seeking inpatient treatment for AUD, especially those with a history of childhood trauma and/or comorbid PTSD, report greater percent time in pain compared to those not seeking treatment and those without AUD. The prolonged experience of pain in abstinent AUD inpatients after the resolution of acute withdrawal may signal the early stages of protracted withdrawal. Integrative treatments targeting pain and other symptoms of protracted withdrawal may be effective in improving overall function in people with severe AUD.

Intermittent Access to Ethanol Induces Escalated Alcohol Consumption in Primates

BACKGROUND

Escalation of voluntary alcohol drinking is characteristic of alcohol addiction and can be induced in rodents using intermittent access to alcohol. This model has been used to evaluate candidate therapeutics, but key systems involved in the transition into alcohol addiction, such as CRF, differ in their organization between rodents and primates. We examined the ability of an intermittent access schedule to induce escalation of voluntary alcohol drinking in non-human primates and used this model to assess the role of corticotropin releasing hormone (CRF) signaling in this process.

METHODS

Four young adult male rhesus macaques were given access to an 8.4% alcohol solution every other weekday (EOD; M, W, F), while four other young adult males were given the same solution every weekday (ED; M-F). Subjects were then administered a CRF1 antagonist, antalarmin.

RESULTS

EOD increased alcohol intake by up to 50% over baseline, with a more pronounced increase immediately following reintroduction of alcohol. For the morning/daytime sessions, EOD subjects increased their consumption by 83% over baseline. Differences between ED and EOD schedules emerged quickly, and EOD-induced escalation resulted in pharmacologically active BAC's. EOD-induced alcohol consumption was insensitive to CRFR1 blockade by antalarmin, but subjects with high CSF levels of CRF were more responsive.

CONCLUSIONS

Similar to what has been observed in rodents, intermittent access results in an escalation of voluntary alcohol drinking in non-human primates. In contrast to findings in rats, recruitment of the CRF system does not seem to be involved in the escalated alcohol drinking observed under these conditions, though individual differences in CRF system activity may play a role.