Predictors of alcohol use among people experiencing chronic pain

Study of the relationship between psychoactive substance use and pain in cancer patients and cancer survivors: A French nationwide cross-sectional study

Pain is a prevalent symptom among cancer patients and survivors. Psychoactive substance use (PSU) is associated with both the presence and severity of pain. However, little is known about this association in the context of cancer. The primary objective was to compare the prevalence of PSU and its relationship with pain during and after cancer. PSU was defined as the use of nonmedication substances (alcohol, tobacco, e-cigarettes, cannabidiol, and cannabis), with frequency categorized as at least yearly, monthly, weekly, or daily. Secondary objectives aimed to explore the relationships between PSU and pain characteristics, health-related quality of life, anxiety, depression, deprivation, and individual characteristics. Among the 1041 individuals included, pain prevalence was 44.7% (95% confidence interval [CI] 41.6%-47.8%). The overall prevalence of PSU at least monthly was 67.0% (95% CI 64.0%-69.8%). The proportions of chronic and neuropathic pains were higher for at least monthly use of cannabidiol compared to nonuse (70.0% vs. 39.3% and 55.7% vs. 28.1%, p < .001). In multivariate analysis, the monthly uses of tobacco and cannabidiol were higher in painful individuals than in nonpainful ones (odds ratio: 2.85 [95% CI 1.22-6.64] and 3.76 [95% CI 1.13-12.44], p < .05). From the point of view of the patient care, the study underscores the need for physicians to prioritize smoking cessation and pay attention to the use of cannabidiol during and after cancer.

Determinants of perceived pain relief from acute alcohol intake in a laboratory setting

Background

Studies of alcohol analgesia often assume that changes in pain sensitivity reflect the negative reinforcing effects of alcohol in pain self-management. However, factors that may influence perceived pain relief due to alcohol use remain incompletely characterized. Thus, the primary aim of this study was to identify which factors are most strongly related to self-reported pain relief in individuals with and without chronic pain after alcohol consumption.

Methods

This study combined data from two studies of alcohol analgesia in individuals who regularly consume alcohol with and without chronic pain. Alcohol analgesia expectancies were assessed during screening. In laboratory sessions, participants received an alcohol-containing (.08 g/dL target BrAC) or placebo beverage and rated subjective intoxication and subjective response (positive/negative aspects of stimulation/sedation). Participants underwent quantitative sensory testing to measure pain intensity, pain threshold, and relief. Paired sample t-tests determined effects of alcohol on pain measures. Hierarchical linear models determined factors associated with pain relief ratings in the alcohol condition.

Results

Pain relief and pain threshold were higher in the alcohol session relative to placebo, but pain intensity did not differ. In a 4-step hierarchical linear model, expectancy of pain relief, subjective intoxication, and high positive affect, but not pain threshold or pain intensity, were significantly and uniquely associated with perceived relief.

Conclusions

Taken together, results suggest the negative-reinforcing effects of alcohol for pain-management are not completely reflected by changes in pain sensitivity in a laboratory setting. Expectancies and subjective response may be important in determining an individual's evaluation of alcohol's efficacy for pain self-management.

Pain Intensity, Pain-Related Anxiety, and Hazardous Drinking Among Individuals With PTSD

OBJECTIVE

Evidence suggests that pain intensity may be indirectly linked to hazardous drinking and PTSD symptom severity via pain-related anxiety. The goal of this analysis was to test the hypotheses in a population with PTSD symptoms that pain intensity would be positively and indirectly associated with hazardous drinking, alcohol dependence, alcohol-related problems, and PTSD symptom severity via pain-related anxiety.

METHODS

Heavy drinkers with probable PTSD were recruited via Qualtrics panels (N = 371, 53% Female, Mage = 39.68, SD = 10.86). Linear regression and conditional process models were conducted to examine indirect associations between pain intensity and primary outcomes via pain-related anxiety.

RESULTS

Pain intensity was found to be indirectly associated with hazardous drinking, alcohol dependence, alcohol-related problems, and PTSD symptom severity via greater pain-related anxiety.

CONCLUSION

These initial findings suggest that pain-related anxiety may play an important role in relations between the experience of pain and hazardous patterns of alcohol consumption among individuals with probable PTSD. Future research is needed to determine the temporal nature of these associations and to examine the potential utility of treatments that address pain-related anxiety in the context of comorbid pain, PTSD, and hazardous drinking.

Associations Between Alcohol and Cannabis Use and Pain Among College Student-Athletes

Background: Pain motivates alcohol and cannabis use, with evidence that pain catastrophizing (i.e., ruminative exaggeration of pain) mediates these associations. Student-athletes represent a unique population who engage in riskier substance use, experience more substance-related consequences, and are more likely to develop chronic pain compared to non-athletes. Objectives: This study examined relationships between pain, catastrophizing, alcohol and cannabis use and consequences. Student-athletes from two Division I universities (N = 549; 51% female) completed a cross-sectional survey. Moderated mediation tested the conditional indirect effect of pain catastrophizing on associations between pain and alcohol- and cannabis- use and consequences, separately, with sex moderating the a and b paths. Results: There was a significant direct effect between pain and alcohol-related consequences (b = 0.11, p = .008). Pain and pain catastrophizing were positively associated in all four models (bs = 0.68-0.72, ps <.001), and this relationship was stronger among female than male athletes. No other direct or conditional indirect effects were observed. Conclusions: Student-athletes experiencing pain report more alcohol-related consequences, and pain catastrophizing may be particularly relevant for student-athletes with greater pain. Future research should examine other factors proposed by theoretical models, such as negative affect, while focusing on athletes with more significant pain (e.g., injured athletes).

Alcohol use severity in relation to pain severity and interference among latinx adults with current pain who smoke cigarettes

Limited research has focused expressly on dual tobacco-alcohol use among the Latinx population. Latinx individuals who smoke represent a tobacco health disparities group and evince elevated rates of pain problems and symptoms. Prior research has consistently linked pain problems and severity to smoking and alcohol prevalence, maintenance, and behavior. Accordingly, the current study sought to build from the limited work that exists among Latinx persons who smoke and evaluate the role of alcohol use severity in terms of pain severity and interference. The current sample consisted of 228 adult Latinx daily cigarette smokers (Mage = 34.95 years; SD = 8.58; 39.0% female) who endorsed current pain. Results indicated that elevated alcohol use problems were associated with greater levels of pain severity (R2 = 0.06) and interference (R2 = 0.06). The present findings suggest that there may be utility in clinical screening for alcohol use problems among Latinx persons who smoke to offset pain problems among this high-risk group.

Lumbar Degenerative Disease and Muscle Morphology Before and After Lower Limb Loss in Four Military Patients

INTRODUCTION

Low back pain (LBP) is highly prevalent after lower limb amputation (LLA). Reports describing longitudinal changes in spine health before and after amputation are rare. This study describes lumbar spine pathology, muscle morphology, and the continuum of care for LBP before and after LLA.

MATERIALS AND METHODS

We queried electronic medical records of patients who sought care for LBP before and after unilateral LLA between January 2002 and April 2020 and who had documented lumbar imaging pre- and post-LLA. Patient demographics, muscle morphology, spinal pathology, premorbid and comorbid conditions, self-reported pain, and treatment interventions were assessed.

RESULTS

Four patients with LBP and imaging before and after LLA were identified. Intervertebral disc degeneration progressed after amputation in three patients, whereas facet arthrosis progressed in both female patients. The fat content of lumbar musculature generally increased after amputation. Conservative management of LBP before and after amputation was standard, with progression to steroidal injections.

CONCLUSIONS

Lumbar spine health may degrade after amputation. Here, lumbar muscle size did not change after LLA, yet the fat content increased in combination with increases in facet and intervertebral disc degeneration.

Inflammatory pain affects alcohol intake in a dose-dependent manner in male rats in the intermittent access model

Introduction

Epidemiological studies have shown that there is a relation between pain and alcohol use disorder (AUD). Persistent pain is directly correlated with an increment in alcohol consumption and an increased risk of developing an AUD. Greater levels of pain intensity and unpleasantness are associated with higher levels of relapse, an increase in alcohol consumption, rates of hazardous drinking, and delay to seek for treatment. However, this interaction has not been deeply studied in the preclinical setting.

Methods

Here, we aim to evaluate how inflammatory pain affects levels of alcohol drinking in male and female rats with a history of alcohol. For that, we used an intermittent access 2-bottle choice paradigm combined with the complete Freund Adjuvant (CFA) model of inflammatory pain.

Results

Our results show that CFA-induced inflammatory pain does not alter total intake of 20% alcohol in male or female rats. Interestingly, in males, the presence of CFA-induced inflammatory pain blunts the decrease of alcohol intake when higher concentrations of alcohol are available, whereas it does not have an effect on intake at any concentration in female rats.

Conclusion

Altogether, this study provides relevant data and constitutes an important contribution to the study of pain and AUD and it highlights the necessity to design better behavioral paradigms in animal models that are more translational and reflect current epidemiological findings.

Benzodiazepine Use and Dependence in Relation to Chronic Pain Intensity and Pain Catastrophizing

Benzodiazepines (BZDs), a class of sedative-hypnotic medications, generated concern as their popularity grew, with particular alarm regarding elevated rates of BZD use among chronic pain populations. Consistent with negative reinforcement/motivational models of substance use, desire for pain alleviation may motivate BZD use. Yet, little is known about relations between pain and addiction-relevant BZD use processes. This cross-sectional survey study aimed to: a) test associations between pain intensity and clinically relevant BZD use patterns, and b) examine the role of pain catastrophizing in hypothesized pain-BZD relations. Participants included 306 adults with chronic musculoskeletal pain and a current BZD prescription who completed an online survey study (Mage = 38.7, 38.9% female). Results indicated that pain intensity was positively associated with past-month BZD use frequency, BZD dependence severity, and likelihood of endorsing BZD misuse behaviors (ps < .05). Pain catastrophizing was positively associated with BZD dependence/likelihood of BZD misuse, covarying for pain intensity (P < .05). These findings build upon an emerging literature by highlighting positive covariation of pain intensity and pain catastrophizing with addiction-relevant BZD use behaviors. Results underscore the need to further investigate high-risk BZD use among individuals with chronic pain, with and without concurrent opioid use, to inform prevention/intervention efforts. PERSPECTIVE: This article presents findings on cross-sectional associations of pain intensity and pain catastrophizing with clinically relevant benzodiazepine (BZD) use outcomes, including dependence and misuse, among individuals with chronic pain. Findings help elucidate the higher burden of BZD misuse/dependence in chronic pain populations and suggest that pain relief may be a common, yet under recognized, self-reported motivation for taking BZDs.

Pain Intensity Moderates the Association between Obsessive-Compulsive Symptoms and Problematic Alcohol Use among Emerging Adults

Objective: Emerging adulthood is a vulnerable period for problematic alcohol use, defined by a pattern of use associated with physical and functional impairment. Obsessive-compulsive psychopathology, which demonstrates high rates of onset in emerging adults, seems to be related to problematic alcohol use in this age group, consistent with research among the general population suggesting an association between emotional disorders and alcohol use in the context of coping drinking motives. Pain intensity, another risk factor of problematic alcohol use, may link obsessive-compulsive symptoms to problematic alcohol use among emerging adults. Therefore, the current study examined the moderating role of pain intensity on the association between obsessive-compulsive symptoms and problematic alcohol use among emerging adults. Methods: Participants were 198 college students (81.30% female, M_age = 22.33, SD = 4.38) who reported problematic alcohol use. Results: Results from the current study supported a significant moderation role of pain intensity for the association between obsessive-compulsive symptoms and problematic alcohol use, whereby the association between obsessive-compulsive symptoms and problematic alcohol use was stronger for emerging adults with high compared to low pain intensity. Conclusions: These results highlighted a clinically-relevant interaction between obsessive-compulsive symptoms and pain intensity concerning the risk of problematic alcohol use among emerging adults as a vulnerable population.

Longitudinal associations between pain and substance use disorder treatment outcomes

INTRODUCTION

Pain is commonly reported among those in treatment for substance use disorders (SUD) and is associated with poorer SUD treatment outcomes. The current study examined the trajectory of pain over the course of SUD treatment and associations with substance use outcomes.

METHODS

This observational study included adults seeking treatment for alcohol, cannabis, or opioid use disorders (N = 811). Participants completed a battery of assessments at treatment admission, 30 days post admission, and at discharge, including measures of demographics, pain, quality of life, abstinence self-efficacy, and craving.

RESULTS

Analyses indicated linear reductions in pain intensity and interference over time. Significant interactive effects were observed for opioid use disorder (OUD) and time, such that participants with OUD had greater reductions in pain intensity and interference over time compared to those without OUD. Elevated pain intensity was associated with negative treatment outcomes, including reduced quality of life and abstinence self-efficacy, and greater craving and negative affect.

CONCLUSIONS

Reductions in pain occur over the course of SUD treatment, particularly for those with OUD. Greater pain was also associated with adverse SUD treatment outcomes. Results suggest that treatment and associated abstinence may be beneficial for those with co-occurring pain and SUD, highlighting an additional benefit of improving access to SUD treatment for patients and health care systems. Future research should replicate these findings among diverse samples and further characterize the trajectory of pain during and after SUD treatment.

Alcohol, Tobacco and Psychotropic Drugs Use Among a Population with Chronic Pain in Southern Spain. A Cross-Sectional Study

BACKGROUND

Substance use seems to be higher among populations with chronic pain.

AIM

The aim of this study is to examine the relationship between the quantity of alcohol, tobacco, and psychotropic drugs consumed and chronic pain among women and men.

METHOD

Linear and logistic regression analyses were carried out using data from the 2015-2016 adults' version of the Andalusian Health Survey which is a representative cross-sectional population-based study (n = 6,569 adults aged >16 years; 50.8% women; 49.2% men).

RESULTS

Disabling chronic pain was statistically associated with higher tobacco consumption among men (β = -30.0, 95% confidenct interval [CI] -59.5 to -0.60; t = -2.0; p < .05). Regarding alcohol, non-disabling chronic pain and a higher quantity of alcohol consumed are statistically associated for both sexes (women: β = 30.4, 95% CI 2.3-58.6; t = 2.12; p < .05 vs. men: β = 164.2, 95% CI 24.3-340.1); t = 2.30; p < .05). For women and men, both disabling chronic pain (women: odds ratio [OR] = 8.7, 95% CI 6.0-12.7); p < .05 vs. men: OR = 3.5, 95% CI 1.5-8.2); p < .05) and non-disabling chronic pain (women: OR = 3.7, 95% CI 2.0-7.0); p <.05 vs. men: OR = 4.7, 95% CI 95% CI 1.5-14.9); p < .05) were statistically significantly associated with a higher consumption of psychotropic drugs.

CONCLUSIONS

Chronic pain may be related to the quantity of alcohol, tobacco, and psychotropic drugs consumed, and disability appears to be one of the factors that modulates this relationship.

Differences in the association between kappa opioid receptors and pain among Black and White adults with alcohol use disorders

BACKGROUND

The relationship between alcohol and pain is complex. Associations between pain and alcohol use disorder (AUD) vary by race, but the underlying biological basis is not understood. We examined the association of the kappa opioid receptor (KOR) with responses to the cold-pressor test (CPT), before and after treatment with the opioid antagonist naltrexone, among individuals with AUD who self-identified as Black or White.

METHODS

Thirty-seven individuals (12 Black, 24 White, and 1 Multiracial) with AUD participated in two CPTs, separated by 1 week during which they received naltrexone 100 mg daily. During each CPT, pain reporting threshold (PRT), average pain increase rate (APIR), relative pain recovery (RPR), and alcohol craving were recorded. KOR availability was measured using [¹¹ C]-LY2795050 positron emission tomography (PET) prior to treatment with naltrexone.

RESULTS

Black participants reported higher PRT and APIR than White participants during the CPT before, but not after, naltrexone treatment. Among Black participants, KOR availability was positively associated with PRT and APIR before, but not after naltrexone. Greater KOR availability was associated with faster RPR for White, but not Black, participants. The CPT induced more alcohol craving in Black than White participants, particularly in individuals with low KOR availability, an effect that was not attenuated by naltrexone.

CONCLUSIONS

KOR involvement and naltrexone effects on responses to the CPT were different between Black and White participants. These preliminary findings suggest that further exploration of the differences in the opioid system and pain among Black and White individuals with AUD and their relationship with naltrexone's effects is warranted.

Does Gender Moderate the Relationship Between Chronic Pain and Substance Use Disorder? Insights From a National Canadian Population Survey

BACKGROUND

Though it has been shown that men have a higher lifetime prevalence of substance use disorder and a lower prevalence of chronic pain than women, there is little research to date focusing on gender differences in the relationship between chronic pain and substance use disorder. This study examined whether gender moderates the relationship of chronic pain and substance use disorder. We also sought to examine the gender differences in the associations between specific pain types-arthritis, migraine, and back pain, and substance use disorder.

METHODS

The data were drawn from the 2012 Canadian Community Health Survey-Mental Health (CCHS-MH 2012) with individuals aged 20 years and older living in the 10 Canadian provinces (N = 23,089). A two-level logistic mixed effects model was used to account for provincial differences.

RESULTS

Our findings indicated gender moderated the association between arthritis as well as migraine, and substance use disorder. However, no moderation effect of gender on the relationship between back pain and substance use disorder was found. Specifically, the strength of the association between arthritis and substance use disorder was stronger among men (OR_interaction = 0.62, 95% CI: 0.53 to 0.73), whereas the strength of the association between migraine and substance use disorder was stronger among women (OR_interaction = 1.45, 95% CI: 1.18 to 1.79). In addition, geographical location was found to explain a small proportion (2.3%-2.4%) of the overall variance in SUD.

CONCLUSIONS

The results suggest that gender moderated the relations between arthritis as well as migraine, and substance use disorder, respectively. Treatment programs for pain and substance misuse might benefit from an approach tailored to gender differences.

Fatigue Severity among Adults with Chronic Low Back Pain: Relations to Opioid Use and Hazardous Alcohol Use

BACKGROUND

Chronic low back pain is the second leading cause of disability in the United States and is related to greater risk of opioid misuse. Research suggests that severe fatigue may be a relevant factor for better understanding the greater rates of opioid and misuse among adults with chronic low back pain. Therefore, the current study sought to examine differences in opioid misuse, risk for opioid use disorder, and hazardous alcohol use in two different groups: one group with clinically significant fatigue, and one group without clinically significant fatigue.

METHODS

Participants were recruited utilizing a validated online survey management system that yielded 1,681 adults (70.0% female, 81.1% White, M _age = 44.5 years, SD = 11.88) with current mild to severe chronic low back pain. One-way analysis of covariance (ANCOVA) models were conducted to examine group differences.

RESULTS

Among adults with chronic low back pain, those with clinically significant fatigue reported significantly greater opioid misuse and risk for opioid use disorder compared to those without clinically significant fatigue. These results were evident after controlling for pain severity and interference. The results for hazardous alcohol use were not significantly different between groups.

CONCLUSIONS

Clinically significant fatigue is a distinguishing characteristic among adults with chronic low back pain in terms of opioid misuse and risk for opioid use disorder. Potential clinical implications of such findings suggest that it may be important for clinicians to assess fatigue levels to better manage opioid misuse potential among adults with chronic low back pain.

A measure of expectancies for alcohol analgesia: Preliminary factor analysis, reliability, and validity

Rates of alcohol consumption are substantially higher among persons with pain, and recent research has focused on elucidating bidirectional pain-alcohol effects. Expectancies for alcohol analgesia could influence the degree to which alcohol confers acute pain-relieving effects, and may amplify the propensity to respond to pain with drinking behavior. However, no validated measures of expectancies for alcohol analgesia are available. Therefore, we developed a five-item measure of Expectancies for Alcohol Analgesia (EAA), which assesses the perceived likelihood that alcohol will reduce pain. The goal of this project was to examine psychometric properties of the EAA among a sample of 273 current alcohol users with chronic pain (M_age = 32.9; 34% female) who completed an online survey of pain and substance use. Confirmatory factor analysis (CFA) results indicated that the hypothesized single-factor structure of the EAA provided good model fit (Bollen-Stine bootstrap p = .13). The EAA also showed excellent internal consistency (α = 0.97), and scores were positively associated with quantity/frequency of alcohol use, alcohol outcome expectancies, coping-related drinking motives, and pain severity (ps < 0.01). These findings provide initial support regarding the single-factor structure, reliability, and validity of the EAA. Examination of predictive utility and further validation are important next steps.

Sex moderates the effects of experimentally induced musculoskeletal pain on alcohol demand in healthy drinkers

BACKGROUND

Pain may serve as an antecedent for alcohol use, increasing risk for hazardous drinking and associated consequences. Delayed onset muscle soreness (DOMS) induction produces clinically relevant but time-limited musculoskeletal pain. This study was conducted to determine whether DOMS induction on the dominant elbow flexors influenced alcohol demand using the Alcohol Purchase Task (APT). We hypothesized DOMS would increase alcohol demand relative to a sham control. Based on existing studies of pain self-medication, we expected DOMS-related increases in alcohol demand would be greatest in men.

METHODS

Participants (N = 53; 57 % women) were randomly assigned to a DOMS (eccentric exercise) or sham condition (concentric exercise). Participants completed the APT pre-exercise and 48 -hs post-exercise. Repeated measures GLM was used to characterize group by sex by time interactions on APT indices, including intensity, breakpoint, essential value (EV), O_max, and P_max.

RESULTS

The DOMS procedure significantly increased pain ratings at the elbow flexors. Men had significantly higher demand intensity than women across groups and time points. Significant interactive effects were detected for breakpoint and EV. From pre- to post-test, breakpoint significantly increased in men in the DOMS group. However, breakpoint and EV significantly decreased in women in the DOMS group.

CONCLUSIONS

Increased alcohol demand in men in the DOMS group was consistent with epidemiological data suggesting men are at higher risk for self-medicating pain with alcohol than women. However, decreased demand in women was unexpected. Taken together, results indicate DOMS induction may be a useful means to characterize pain as an antecedent for alcohol use.

Drug Addiction: Hyperkatifeia/Negative Reinforcement as a Framework for Medications Development

Compulsive drug seeking that is associated with addiction is hypothesized to follow a heuristic framework that involves three stages (binge/intoxication, withdrawal/negative affect, and preoccupation/anticipation) and three domains of dysfunction (incentive salience/pathologic habits, negative emotional states, and executive function, respectively) via changes in the basal ganglia, extended amygdala/habenula, and frontal cortex, respectively. This review focuses on neurochemical/neurocircuitry dysregulations that contribute to hyperkatifeia, defined as a greater intensity of negative emotional/motivational signs and symptoms during withdrawal from drugs of abuse in the withdrawal/negative affect stage of the addiction cycle. Hyperkatifeia provides an additional source of motivation for compulsive drug seeking via negative reinforcement. Negative reinforcement reflects an increase in the probability of a response to remove an aversive stimulus or drug seeking to remove hyperkatifeia that is augmented by genetic/epigenetic vulnerability, environmental trauma, and psychiatric comorbidity. Neurobiological targets for hyperkatifeia in addiction involve neurocircuitry of the extended amygdala and its connections via within-system neuroadaptations in dopamine, enkephalin/endorphin opioid peptide, and γ-aminobutyric acid/glutamate systems and between-system neuroadaptations in prostress corticotropin-releasing factor, norepinephrine, glucocorticoid, dynorphin, hypocretin, and neuroimmune systems and antistress neuropeptide Y, nociceptin, endocannabinoid, and oxytocin systems. Such neurochemical/neurocircuitry dysregulations are hypothesized to mediate a negative hedonic set point that gradually gains allostatic load and shifts from a homeostatic hedonic state to an allostatic hedonic state. Based on preclinical studies and translational studies to date, medications and behavioral therapies that reset brain stress, antistress, and emotional pain systems and return them to homeostasis would be promising new targets for medication development. SIGNIFICANCE STATEMENT: The focus of this review is on neurochemical/neurocircuitry dysregulations that contribute to hyperkatifeia, defined as a greater intensity of negative emotional/motivational signs and symptoms during withdrawal from drugs of abuse in the withdrawal/negative affect stage of the drug addiction cycle and a driving force for negative reinforcement in addiction. Medications and behavioral therapies that reverse hyperkatifeia by resetting brain stress, antistress, and emotional pain systems and returning them to homeostasis would be promising new targets for medication development.

Neurobiological aspects of pain in the context of alcohol use disorder

Alcohol is an effective and widely utilized analgesic. However, the chronic use of alcohol can actually facilitate nociceptive sensitivity over time, a condition known as hyperalgesia. Excessive and uncontrollable alcohol drinking is also a hallmark feature of alcohol use disorder (AUD). Both AUD and chronic pain are typically accompanied by negative affective states that may underlie reinforcement mechanisms contributing to AUD maintenance or progression. Frequent utilization of alcohol to relieve pain in individuals suffering from AUD or other chronic pain conditions may thus represent a powerful negative reinforcement construct. This chapter will describe ties between alcohol-mediated pain relief and potential exacerbation of AUD. We describe neurobiological systems engaged in alcohol analgesia as well as systems recruited in the development and maintenance of AUD and hyperalgesia. Although few effective therapies exist for either chronic pain or AUD, the common interaction of these conditions will likely lead the way for promising new discoveries of more effective and even simultaneous treatment of AUD and co-morbid hyperalgesia. An abundance of neurobiological findings from multiple laboratories has implicated a potentiation of central amygdala (CeA) signaling in both pain and AUD, and these data also suggest that attenuation of stress-related systems (including corticotropin-releasing factor, vasopressin, and glucocorticoid receptor activity) would be particularly effective and comprehensive therapeutic strategies targeting the critical intersection of somatic and motivational mechanisms driving AUD, including alcohol-induced hyperalgesia.

CANUE: A Theoretical Model of Pain as an Antecedent for Substance Use

BACKGROUND

Pain and substance use are frequently comorbid and have been shown to exert bidirectional effects. Self-medication of pain and distress via substance use is common and can be understood via negative reinforcement, ultimately strengthening the pathway between pain to substance use over time. As such, a testable model of the potentially modifiable candidate mechanisms that underlie the pain to substance use pathway is needed.

PURPOSE

This review proposes a testable model of pain as an antecedent to substance use to guide future research and inform clinical practice.

METHODS

An integrative review of current evidence regarding pain, substance use, and associated risk factors (i.e., negative affect, pain-related attitudes, negative urgency, and substance use outcome expectancies) was conducted.

RESULTS

The Catastrophizing, Anxiety, Negative Urgency, and Expectancy (CANUE) model highlights modifiable risk factors for self-medicating pain with substance use, including increased negative affect and maladaptive pain-related attitudes (i.e., pain catastrophizing, pain anxiety, and fear of pain), negative urgency, and substance-related outcome expectancies for pain relief and enhanced pain coping.

CONCLUSIONS

Targeted behavioral and psychological interventions that address these factors may facilitate more adaptive pain-coping responses, thereby reducing the impacts of pain on substance use. Systematic research is needed to evaluate the validity and clinical utility of this model.

The Moderating Role of Fatigue Sensitivity in the Relation between Depression and Alcohol and Opioid Misuse among Adults with Chronic Low Back Pain

OBJECTIVE

Chronic low back pain is the second leading cause of disability in the United States and is frequently related to increased risk of opioid and alcohol misuse. Depression is associated with poor substance use outcomes among persons with chronic low back pain. Theoretically, the influence of depression on opioid and alcohol misuse among those with chronic low back pain may vary as a function of fatigue sensitivity.

METHOD

To empirically test this theorized model, the current study examined fatigue sensitivity as a moderator for the relation between depression and opioid and alcohol misuse among 291 adults (69.1% female, M _age = 45.77 years, SD = 11.22) with chronic low back pain currently using opioids.

RESULTS

Results suggested that fatigue sensitivity moderated the effect of depression on opioid misuse (β=0.60, p= .001, 95%CI [0.02, 0.06]) and alcohol misuse (β=0.45, p= .025, 95%CI [0.002, 0.03]). Examination of simple slopes revealed that the association between depression and opioid and alcohol misuse was statistically significant for those with higher levels of fatigue sensitivity, but not lower levels of fatigue sensitivity.

CONCLUSIONS

Overall, the current investigation provides initial empirical support for the moderating role of fatigue sensitivity in the relation between depression and alcohol and opioid misuse among adults with chronic low back pain.

Pain-induced alterations in the dynorphinergic system within the mesocorticolimbic pathway: Implication for alcohol addiction

Latest studies have revealed that pain negatively impacts on reward processing and motivation leading to negative affective states and stress. These states not only reduce quality of life of patients by increasing the appearance of psychiatric comorbidities, but also have an important impact on vulnerability to drug abuse, including alcohol. In fact, clinical, epidemiological but also preclinical studies have revealed that the presence of pain is closely related to alcohol use disorders (AUDs). All this evidence suggests that pain is a factor that increases the risk of suffering AUD, predicting heavy drinking behavior and relapse drinking in those patients with a previous history of AUD. The negative consequences of chronic pain and its impact on stress and AUD are likely mediated by alterations in the central nervous system, especially in the stress and reward systems. Therefore, pain and stress impact on dopaminergic mesolimbic pathway can lead to an increase in drug abuse liability. In this mini review we analyze the interaction between pain, stress, and alcohol addiction, and how dynamic changes in the kappa opioid system might play a crucial role in the development of compulsive alcohol drinking in chronic pain patients.

Effects of oral alcohol administration on heat pain threshold and ratings of supra-threshold stimuli

Background and aims Evidence for analgesic effects of oral alcohol consumption on heat pain has recently been documented in a placebo-controlled, randomized and double-blind design. We aimed at further investigating these effects and now set the focus on pain threshold and the ratings of supra-threshold pain to cover most of the pain range. Moreover, we now firstly evaluated sex differences in these effects. Methods We investigated 41 healthy participants (22 females) in a randomized, double-blind and placebo-controlled design and targeted two different moderate breath-alcohol levels of 0.06% and 0.08%. Before and after an alcoholic or placebo drink, contact heat was applied at the forearm. Subjects evaluated pain threshold (method of adjustment) and rated pain intensity and pain unpleasantness of supra-threshold stimuli (intensity: threshold +3 °C; duration: 5 s). Results Analgesic effects taking the form of increased pain thresholds were found after both alcohol doses, surprisingly with more pronounced effects for the lower dose. While the high alcohol dose exerted small analgesic effects on pain intensity ratings (i.e. decrease), slightly increased ratings of pain intensity and pain unpleasantness after the low alcohol dose rather suggest pain enhancement. Alcohol did not affect intensity vs. unpleasantness ratings differentially. We found no evidence for sex differences in any of these effects. Conclusions Overall, acute alcohol effects on pain were subtle. Our findings suggest that while low alcohol doses already exert analgesic effects on pain threshold, stronger doses are required for pain reduction on supra-threshold pain levels. Furthermore, sex differences could not be detected within our experimental paradigm but should be further explored in future research. Implications Analgesic effects of sub-toxic alcohol doses - as normally occurring during social drinking - might be weak; however, susceptibility to pain relieving effects of alcohol might be a risk factor for the use of alcohol as self-medication in acute pain states.

Neuropeptide and cytokine regulation of pain in the context of substance use disorders

Substance use disorders (SUDs) are frequently accompanied by affective symptoms that promote negative reinforcement mechanisms contributing to SUD maintenance or progression. Despite their widespread use as analgesics, chronic or excessive exposure to alcohol, opioids, and nicotine produces heightened nociceptive sensitivity, termed hyperalgesia. This review focuses on the contributions of neuropeptide (CRF, melanocortin, opioid peptide) and cytokine (IL-1β, TNF-α, chemokine) systems in the development and maintenance of substance-induced hyperalgesia. Few effective therapies exist for either chronic pain or SUD, and the common interaction of these disease states likely complicates their effective treatment. Here we highlight promising new discoveries as well as identify gaps in research that could lead to more effective and even simultaneous treatment of SUDs and co-morbid hyperalgesia symptoms.

The Influence of Tobacco Use, Alcohol Consumption, and Weight Gain on Development of Secondary Musculoskeletal Injury After Lower Limb Amputation

OBJECTIVES

To evaluate whether tobacco use, alcohol consumption, and weight gain are associated with the diagnosis of overuse musculoskeletal injuries within the first 12 months after lower limb amputation.

DESIGN

Retrospective cohort study.

SETTING

Military treatment facilities.

PARTICIPANTS

Service members (N=681) with a deployment-related lower limb amputation.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Clinical diagnosis codes associated with musculoskeletal overuse injuries of the lower limb, upper limb, and low back regions.

RESULTS

In the first three months after amputation, tobacco use and alcohol consumption were reported in 55.7% and 72.0%, respectively, of the retrospective sample. The overall mean weight change was 22.9±23.6 pounds. The prevalence of reporting at least 1 overuse injury within 4 to 12 months after amputation was 57.0% in the sample, with prevalence rates of lower limb, upper limb and low back pain diagnoses at 28.3%, 21.7%, and 21.1%, respectively. Service members reporting tobacco use in the first 3 months after amputation were nearly twice as likely to be diagnosed with a lower limb musculoskeletal injury 4 to 12 months after amputation. Similarly, service members reporting alcohol consumption within the first 3 months after amputation were more than twice as likely to be diagnosed with at least 1 overuse musculoskeletal injury 4 to 12 months after amputation. However, weight change or maximum weight after amputation were not associated with the diagnosis of an overuse musculoskeletal injury.

CONCLUSIONS

Development of secondary overuse musculoskeletal injury appears to be related to tobacco use and alcohol consumption, but not to weight gain. These findings warrant focused research efforts toward developing preventive interventions.

Pain Severity and Alcohol Use Among Daily Tobacco Cigarette Smokers

BACKGROUND AND OBJECTIVES

Pain is associated with hazardous alcohol use. Drinkers have reported using alcohol for pain-coping, and negative affect may be a key mechanism in pain-induced motivation to drink. However, no previous study has examined pain severity in relation to alcohol consumption, dependence, and alcohol-related consequences. Moreover, no studies have examined pain-alcohol interrelations among tobacco cigarette smokers. These secondary analyses tested the hypotheses that greater past 4-week pain severity would be positively associated with indices of hazardous drinking (ie, quantity/frequency, harmful use, and dependence), and that the current pain intensity would be positively/indirectly associated with the urge to drink via negative affect.

METHODS

Participants included 225 daily smokers (43% female; M_CPD  = 22) who completed the baseline session for a larger experimental study.

RESULTS

Every one-point increase in pain severity was associated with a 47% increased likelihood of hazardous drinking, and pain severity was positively associated with quantity/frequency of alcohol consumption, harmful patterns of drinking, and alcohol dependence level (Ps < .05). Pain intensity was indirectly associated with urge to drink via negative affect (P < .05).

CONCLUSIONS

These findings provide initial evidence that smokers with greater pain severity may also report hazardous patterns of alcohol use.

SCIENTIFIC SIGNIFICANCE

This is the first study to demonstrate that past 4-week pain severity may be one factor that maintains three conceptually distinct patterns of hazardous drinking among smokers. The current results also provide the first evidence that greater pain intensity may be associated with an increased urge to drink alcohol, via negative affect. (Am J Addict 2020;29:134-140).

Pain severity and prescription opioid misuse among individuals with chronic pain: The moderating role of alcohol use severity

BACKGROUND

Chronic pain is a public health problem associated with opioid misuse. Yet, it is important to understand factors underlying opioid misuse in the context of pain. Alcohol use is one factor to consider given past work documenting use of alcohol to manage pain. However, it is unknown whether alcohol use severity exacerbates the relation between pain and opioid misuse. This study sought to examine relations between pain and prescription opioid misuse and the moderating role of alcohol use severity in two online survey studies of individuals with chronic pain.

METHOD

Individuals with chronic pain (study 1, n = 364; study 2, n = 437) were administered measures of pain, alcohol use, and opioid misuse.

RESULTS

In study 1, there was a significant interaction of pain severity and alcohol use (b = 0.16, p < 0.001). Pain was significantly related to opioid misuse among those with higher (b = 1.50, p < 0.001), but not lower (b=-0.26, p = 0.430) alcohol use. In study 2, there was a significant interaction of pain severity and alcohol use (b = 0.03, p < 0.001). Pain was significantly related to opioid misuse among those with higher (b = 0.74, p < 0.001), but not lower (b = 0.07, p = 0.620) alcohol use.

CONCLUSIONS

In two online samples, there was evidence of a novel interaction of pain severity and alcohol use severity in relation to opioid misuse. Although cross-sectional, results replicated in two studies. Pain severity was related to opioid misuse among those with higher but not lower alcohol use. Those who use alcohol, even below suggested cut-offs, may be more likely to misuse opioids when in pain.

Is there a relationship between cannabis use problems, emotion dysregulation, and mental health problems among adults with chronic pain?

Cannabis is often used to manage pain among persons who suffer from chronic pain. Yet, despite much literature suggesting cannabis use problems are associated with mental health problems, little work has examined mechanisms of this relationship among a chronic pain population. Chronic pain is also associated with emotion dysregulation. Individuals with chronic pain who experience cannabis use problems may have less capacity to regulate negative emotions, which could relate to greater anxiety, depression, and suicidal ideation. Thus, the current study explored whether emotion dysregulation explained, in part, the relation between cannabis use problems and anxiety, depression, and suicidal ideation among adults with chronic pain. Participants were 431 opioid-using adults with current moderate to severe chronic pain, 176 were current cannabis users, of which 30.20% reported cannabis use problems. Results indicated a significant indirect relationship between cannabis use problems and anxiety [95% CI (.03, .05)], depression [95% CI (.03, .06)], and suicidal ideation [95% CI (.01, .01)] via emotion dysregulation. Tests of specificity suggested potential for a bi-directional effect for suicidal ideation (p < .001). Initial findings suggest that emotion dysregulation may be an important mechanism in the relationship between cannabis use problems and mental health among adults with chronic pain.

Gender differences in associations between pain-related anxiety and alcohol use among adults with chronic pain

Background: Over 100 million Americans live with chronic pain, and adults with chronic pain may be more likely to experience alcohol-related problems or Alcohol Use Disorder. An evolving conceptual model posits that bidirectional effects between pain and alcohol exacerbate both pain and drinking. Pain has been shown to motivate alcohol urge and consumption, and drinking for pain-coping predicts escalations in alcohol use over time. Pain-related anxiety is a transdiagnostic vulnerability factor that has been implicated in both pain and substance-related (i.e., tobacco, opioids, cannabis) outcomes, but has not yet been studied in relation to alcohol use. Objective: We sought to conduct the first test of cross-sectional associations between pain-related anxiety, gender, and alcohol use. Methods: Adults with chronic pain (N = 234; M_age = 29.54, 67% Female) self-reported pain-related anxiety, gender, and alcohol use (i.e., consumption frequency/quantity, alcohol-related consequences, and dependence symptoms measured with the Alcohol Use Disorders Identification Test; AUDIT). Hierarchical regression and conditional effects models were used to test associations between pain-related anxiety, gender, and alcohol use. Results: Pain-related anxiety was positively associated with alcohol-related consequences and alcohol dependence symptoms measured by the AUDIT among males, but not females. Pain-related anxiety was not associated with the frequency/quantity of alcohol consumption in our sample. Conclusions: These findings are consistent with prior research, which has demonstrated associations between pain-related anxiety and deleterious substance use outcomes. Results provide initial evidence that pain-related anxiety may be a relevant factor to consider in the context of alcohol research and treatment among male drinkers.

A Novel Role for the Endocannabinoid System in Ameliorating Motivation for Alcohol Drinking and Negative Behavioral Affect after Traumatic Brain Injury in Rats

Traumatic brain injury (TBI) is associated with psychiatric dysfunction-including pain, cognitive impairment, anxiety, and increased alcohol use. We previously demonstrated that inhibiting endocannabinoid degradation post-TBI with JZL184 attenuates neuroinflammation and neuronal hyperexcitability at the site of injury and improves neurobehavioral recovery. This study aimed to determine the effect of JZL184 on post-TBI behavioral changes related to psychiatric dysfunction and post-TBI neuroadaptations in brain regions associated with these behaviors. We hypothesized that JZL184 would attenuate post-TBI behavioral and neural changes in alcohol-drinking rats. Adult male Wistar rats were trained to operantly self-administer alcohol before receiving lateral fluid percussion injury. Thirty minutes post-TBI, rats received JZL184 (16 mg/kg, i.p.) or vehicle. Spatial memory (Y-maze), anxiety-like behavior (open field), alcohol motivation (progressive ratio responding), and mechanosensitivity (Von Frey) were measured 3-10 days post-injury, and ventral striatum (VS) and central amygdala (CeA) tissue were collected for western blot analysis of phosphorylated glutamate receptor subunit 1 (GluR1) and glucocorticoid receptor (GR). TBI impaired spatial memory, increased anxiety-like behavior, and increased motivated alcohol drinking. JZL184 prevented these changes. TBI also increased phosphorylated GluR1 and GR in the CeA (but not the VS) compared with sham controls. JZL184 attenuated post-TBI GR phosphorylation in the CeA. These findings suggest that TBI produces comorbid cognitive dysfunction, increased alcohol motivation, and anxiety-like behavior, possibly related to amygdala dysfunction, and these changes are prevented by systemic post-TBI endocannabinoid degradation inhibition. Thus, boosting endocannabinoid tone post-TBI may represent a viable therapeutic strategy for TBI-related psychiatric comorbidities such as alcohol use disorder and anxiety.

Substance-related disorders: A review of prevalence and correlates among patients with chronic pain

Over the past few decades, research has revealed high rates of substance-related disorders among patients with chronic pain. In addition to their potentially deleterious health consequences, substance-related disorders have consistently been associated with negative pain-related outcomes among patients with chronic pain. The goal of this narrative review was to provide an overview of studies that have examined the prevalence and correlates of substance-related disorders among patients with chronic pain. A particular focus was placed on opioids, sedatives/hypnotics, cannabis, tobacco, and alcohol given that these substances have received the bulk of research attention among patients with pain. Research conducted to date suggests that a host of biological and psychological factors are likely to contribute to the elevated rates of substance-related disorders among patients with chronic pain. In this review, in addition to reviewing the prevalence and correlates of substance-related disorders among patients with pain, we briefly discussed the changes that were recently made from the DSM-4 to the DSM-5 in the diagnostic criteria for substance-related disorders, and the implications of these changes for the assessment of patients with chronic pain. We also provided a brief overview of instruments that can be used for the assessment of these disorders in clinical and research settings.

A Reciprocal Model of Pain and Substance Use: Transdiagnostic Considerations, Clinical Implications, and Future Directions

Pain and substance use are highly prevalent and co-occurring conditions that continue to garner increasing clinical and empirical interest. Although nicotine and tobacco, alcohol, and cannabis each confer acute analgesic effects, frequent or heavy use may contribute to the development and progression of chronic pain, and pain may be heightened during abstinence. Additionally, pain can be a potent motivator of substance self-administration, and it may contribute to escalating use and poorer substance-related treatment outcomes. We integrated converging lines of evidence to propose a reciprocal model in which pain and substance use are hypothesized to interact in the manner of a positive feedback loop, resulting in the exacerbation and maintenance of both conditions over time. Theoretical mechanisms in bidirectional pain-substance use relations are reviewed, including negative reinforcement, social cognitive processes, and allostatic load in overlapping neural circuitry. Finally, candidate transdiagnostic factors are identified, and we conclude with a discussion of clinical implications and future research directions.

Dynamic daily associations between insomnia symptoms and alcohol use in adults with chronic pain

Individuals with chronic pain are at risk for sleep disruption and heavy alcohol use, yet the daily associations between these behaviours are not well characterized. This study aimed to determine the extent to which alcohol use affects insomnia symptoms and vice versa in adults reporting symptoms of chronic pain. Participants were 73 individuals (93% women) reporting alcohol use in addition to symptoms of insomnia and chronic pain. They completed daily diaries assessing insomnia symptoms and alcohol use for 14 days. Multilevel modelling was used to evaluate the bidirectional associations between alcohol use and insomnia symptoms at the daily level. Consistent with laboratory-based research, alcohol use was associated with decreased sleep-onset latency the same night but increased sleep-onset latency 2 nights later. Specifically, for every alcoholic drink consumed, time to sleep onset decreased by 5.0 min in the same night but increased by 4.3 min 2 nights later. Alcohol use was not significantly associated with subsequent wake after sleep onset or total sleep time, and insomnia symptoms were not significantly associated with subsequent alcohol use. To our knowledge, these data provide the first evidence that alcohol use negatively affects insomnia symptoms up to 2 days post-consumption in patients reporting symptoms of insomnia and chronic pain. Findings suggest that one drink will have minimal impact on sleep, but heavier drinking (e.g. four-five drinks) may have a clinically significant impact (16-25-min increase in sleep-onset latency). Future studies may assess alcohol use as a point of intervention within this population.

Individual Variation in Pain Sensitivity and Conditioned Pain Modulation in Acute Low Back Pain: Effect of Stimulus Type, Sleep, and Psychological and Lifestyle Factors

Generalized hyperalgesia and impaired pain modulation are reported in chronic low back pain (LBP). Few studies have tested whether these features are present in the acute phase. This study aimed to test for differences in pain presentation in early-acute LBP and evaluate the potential contribution of other factors to variation in sensitivity. Individuals within 2 weeks of onset of acute LBP (n = 126) and pain-free controls (n = 74) completed questionnaires related to their pain, disability, behavior, and psychological status before undergoing conditioned pain modulation (CPM) and pain threshold (heat, cold, and pressure) testing at the back and forearm/thumb. LBP participants were more sensitive to heat and cold at both sites and pressure at the back than controls, without differences in CPM. Only those with high-pain (numeric rating scale ≥4) were more sensitive to heat at the forearm and pressure at the back. Four subgroups with distinct features were identified: "high sensitivity," "low CPM efficacy," "high sensitivity/low CPM efficacy," and "low sensitivity/high CPM efficacy." Various factors such as sleep and alcohol were associated with each pain measure. Results provide evidence for generalized hyperalgesia in many, but not all, individuals during acute LBP, with variation accounted for by several factors. Specific pain phenotypes provide candidate features to test in longitudinal studies of LBP outcome.

PERSPECTIVE

Sensory changes indicative of increased/decreased central processing of pain and nociceptive input presented differently between individuals with acute LBP and were related to factors such as sleep and alcohol. This may underlie variation in outcome and suggest potential for early identification of individuals with poor long-term outcome.

Alcohol and Opioid Use, Co-Use, and Chronic Pain in the Context of the Opioid Epidemic: A Critical Review

The dramatic increase in opioid misuse, opioid use disorder (OUD), and opioid-related overdose deaths in the United States has led to public outcry, policy statements, and funding initiatives. Meanwhile, alcohol misuse and alcohol use disorder (AUD) are a highly prevalent public health problem associated with considerable individual and societal costs. This study provides a critical review of alcohol and opioid misuse, including issues of prevalence, morbidity, and societal costs. We also review research on interactions between alcohol and opioid use, the influence of opioids and alcohol on AUD and OUD treatment outcomes, respectively, the role of pain in the co-use of alcohol and opioids, and treatment of comorbid OUD and AUD. Heavy drinking, opioid misuse, and chronic pain individually represent significant public health problems. Few studies have examined co-use of alcohol and opioids, but available data suggest that co-use is common and likely contributes to opioid overdose-related morbidity and mortality. Co-use of opioids and alcohol is related to worse outcomes in treatment for either substance. Finally, chronic pain frequently co-occurs with use (and co-use) of alcohol and opioids. Opioid use and alcohol use are also likely to complicate the treatment of chronic pain. Research on the interactions between alcohol and opioids, as well as treatment of the comorbid disorders is lacking. Currently, most alcohol research excludes patients with OUD and there is lack of measurement in both AUD and OUD research in relation to pain-related functioning. Research in those with chronic pain often assesses opioid use, but rarely assesses alcohol use or AUD. New research to examine the nexus of alcohol, opioids, and pain, as well as their treatment, is critically needed.

Effects of experimental pain induction on alcohol urge, intention to consume alcohol, and alcohol demand

Research suggests one determinant of alcohol consumption may be physical pain, but there is no empirical evidence that pain has a causal effect on drinking. Therefore, the primary aim of this study was to test experimental pain as a determinant of several alcohol consumption proxies: self-reported urge to drink, intention to consume alcohol, and alcohol demand. This study also was designed to test negative affect as a mediator of the effects of pain on alcohol use proxies. We hypothesized that participants randomized to experimental pain induction (vs. no pain) would report greater urge, intention, and alcohol demand, and that these effects would be mediated by increased negative affect. Participants were healthy undergraduates who were moderate-heavy drinkers (N = 61). Experimental pain was induced using a novel capsaicin-heat model intended to approximate key features of clinical pain. Results indicated that participants in the pain condition subsequently endorsed greater urge and intention to drink. Furthermore, these effects were mediated by pain-induced negative affect. We observed no effect of pain on alcohol demand. This is the first study to demonstrate a causal effect of acute pain on urge and intention to drink. Given the close association between alcohol consumption, urge and intention to drink, these findings suggest that pain may influence alcohol consumption, which can have implications for individuals with co-occurring pain and alcohol use disorder (AUD). Specifically, individuals with co-occurring pain and AUD may drink to alleviate pain-related negative affect. Therefore, improving pain-coping skills may enhance pain-management abilities, subsequently reducing coping-motivated drinking. (PsycINFO Database Record

Analgesic Effects of Alcohol: A Systematic Review and Meta-Analysis of Controlled Experimental Studies in Healthy Participants

Despite the long-standing belief in the analgesic properties of alcohol, experimental studies have produced mixed results. This meta-analysis aimed to clarify whether alcohol produces a decrease in experimentally-induced pain and to determine the magnitude of any such effect. PubMed, PsycINFO, and Embase databases were searched from inception until April 21, 2016 for controlled studies examining the effect of quantified dosages of alcohol on pain response to noxious stimulation. Eighteen studies involving 404 participants were identified providing alcohol versus no-alcohol comparisons for 13 tests of pain threshold (n = 212) and 9 tests of pain intensity ratings (n = 192). Random effects meta-analysis of standardized mean difference (SMD) provided robust support for analgesic effects of alcohol. A mean blood alcohol content (BAC) of approximately .08% (3-4 standard drinks) produced a small elevation of pain threshold (SMD [95% CI] = .35 [.17-.54], P = .002), and a moderate to large reduction in pain intensity ratings (SMD [95% CI] = .64 [.37-.91], P < .0001), or equivalently, a mean reduction of 1.25 points on a 0- to 10-point pain rating scale. Furthermore, increasing BAC resulted in increasing analgesia, with each .02% BAC increment producing an increase of SMD = .11 for pain threshold and SMD = .20 for reduced pain intensity. Some evidence of publication bias emerged, but statistical correction methods suggested minimal impact on effect size. Taken together, findings suggest that alcohol is an effective analgesic that delivers clinically-relevant reductions in ratings of pain intensity, which could explain alcohol misuse in those with persistent pain despite its potential consequences for long-term health. Further research is needed to corroborate these findings for clinical pain states.

PERSPECTIVE

This meta-analysis provides robust evidence for the analgesic properties of alcohol, which could potentially contribute to alcohol misuse in pain patients. Strongest analgesia occurs for alcohol levels exceeding World Health Organization guidelines for low-risk drinking and suggests raising awareness of alternative, less harmful pain interventions to vulnerable patients may be beneficial.

Pain, alcohol use disorders and risky patterns of drinking among people with chronic non-cancer pain receiving long-term opioid therapy

BACKGROUND

The utilisation of pharmaceutical opioids has increased internationally, and there is evidence of increasing risky alcohol consumption with ageing. This study examines the patterns and correlates of risky drinking among people with chronic non-cancer pain (CNCP) prescribed opioids, and the associations between alcohol consumption and pain.

METHODS

The Pain and Opioids IN Treatment cohort comprises 1514 people in Australia prescribed pharmaceutical opioids for CNCP. Participants reported lifetime, past year and past month alcohol use, as well as mental and physical health, other substance use, pain characteristics, and current opioid dose.

RESULTS

Less than one-tenth of the sample were 'lifetime abstainers' (7%); 34% were 'former drinkers'; 34% were 'non-risky drinkers' (i.e., past 12 month use ≤4 standard drinks); 16% were 'occasional risky drinkers'; and 8% were 'regular risky drinkers' (i.e., ≥weekly use of >4 standard drinks). Males reported greater levels of alcohol use, and a third (33%) of the total sample reported a lifetime alcohol use disorder. Controlling for demographics, mental health, physical health and substance use disorder history, 'former drinkers' (cf. 'non-risky drinkers') reported higher pain severity and interference ratings, and lower pain coping. 'Occasional risky drinkers' and 'regular risky drinkers' (cf. 'non-risky drinkers') reported higher levels of pain interference.

CONCLUSIONS

Among people with CNCP, those who abstained from alcohol or drank at risky levels reported poorer pain outcomes compared with moderate drinkers. Early identification and intervention for risky drinking among people is critical, particularly given the risks associated with co-administration of alcohol and opioids.

The effect of nonrecurring alcohol administration on pain perception in humans: a systematic review

Purpose

Alcohol is believed to have pain-dampening effects and is often used as self-medication by persons with pain problems; however, experimental evidence confirming this effect is scarce. We conducted a systematic review of experimental studies on the effects of nonrecurring alcohol administration on pain perception in healthy human subjects and the underlying mechanisms.

Method

Three databases (PubMed, PsycINFO, and Web of Science) were searched for relevant studies using a predefined algorithm. In a next step, irrelevant articles were excluded by screening titles and abstracts. Finally, articles were checked regarding a set of methodological criteria; only publications meeting these criteria were selected for this review. A total of 14 experimental studies were identified.

Results

Overall, most of the studies were able to show a pain-dampening effect of alcohol. However, many of them had methodological shortcomings (eg, lack of placebo control, insufficient blinding, or very small sample sizes). In addition, comparability is limited due to considerable variations in alcohol administration and pain measurement. More importantly, potential mechanisms of action and moderating variables have scarcely been investigated.

Conclusion

Despite the frequent use of alcohol as self-medication by persons with pain problems, there are to date only a few experimental investigations of alcohol effects on pain perceptions. The results of these studies suggest that alcohol does in fact have pain-dampening effects. However, the mechanisms implicated in these effects are still unknown, and experimental research has been limited to pain-free subjects. Future research should provide more knowledge about alcohol effects on pain, especially in chronic pain patients.

Interrelations between pain and alcohol: An integrative review

Pain and alcohol use are both highly prevalent in the general population, and pain-alcohol interrelations are of increasing empirical interest. Previous research has identified associations between pain and alcohol dependence, and the current review provides novel contributions to this emerging domain by incorporating studies that have tested relations between pain and low-to-moderate alcohol consumption, and by identifying potential psychosocial mechanisms of action. Specifically, we sought to integrate evidence of pain-alcohol relations derived from two directions of empirical inquiry (i.e., effects of alcohol on pain and effects of pain on alcohol use) across psychological, social, and biological literatures. We observed converging evidence that associations between alcohol consumption and pain may be curvilinear in nature. Whereas moderate alcohol use was observed to be associated with positive pain-related outcomes (e.g., greater quality of life), excessive drinking and alcohol use disorder appear to be associated with deleterious pain-related outcomes (e.g., greater pain severity). We also observed evidence that alcohol administration confers acute pain-inhibitory effects, and that situational pain may motivate alcohol consumption (e.g., drinking for pain-coping). Future research can inform theoretical and clinical applications through examination of temporal relations between pain and alcohol consumption, tests of hypothesized mechanisms, and the development of novel interventions.

Pain and use of alcohol in later life: prospective evidence from the health and retirement study

OBJECTIVE

To determine whether (a) late-life pain predicts growth in older adults' use of alcohol, and elevated risk of drinking problems; and (b) sociodemographic characteristics moderate these relationships.

METHOD

Five times over an 8-year interval, N = 5,446 Health and Retirement Study (HRS) participants provided information about their pain and alcohol use. Two-part latent growth modeling and logistic regression were used to analyze these data.

RESULTS

Participants with more pain at baseline had lower initial levels and a faster rate of decline over the next 8 years in alcohol consumption, but they also were at elevated risk of having drinking problems. Income and African American background interacted with pain to predict 8-year change in alcohol consumption and presence of drinking problems.

DISCUSSION

Late-life pain does not predict growth in older adults' alcohol consumption, but is nonetheless linked to elevated risk of drinking problems, especially among African Americans.

Predictors of pain among patients with head and neck cancer

OBJECTIVE To determine predictors of pain 1 year after the diagnosis of head and neck cancer. DESIGN Prospective, multisite cohort study. SETTING Three academically affiliated medical centers. PATIENTS The study population comprised 374 previously untreated patients with carcinoma of the upper aerodigestive tract. MAIN OUTCOME MEASURES Participants were surveyed before treatment and 1 year thereafter. Multivariate analyses were conducted to determine predictors of the 36-Item Short-Form Instrument (SF-36) bodily pain score 1 year after diagnosis. RESULTS The mean SF-36 bodily pain score at 1 year was 65, compared with 61 at the time of diagnosis (P = .004), and 75, the population norm (lower scores indicate worse pain). Variables independently associated with pain included pretreatment pain score (P &lt; .001), less education (P = .02), neck dissection (P = .001), feeding tube (P = .05), xerostomia (P &lt; .001), depressive symptoms (P &lt; .001), taking more pain medication (P &lt; .001), less physical activity (P = .02), and poor sleep quality (P = .006). The association between head and neck cancer pain and current smoking and problem drinking did not reach significance (P = .07 and P = .08, respectively). CONCLUSIONS Aggressive pain management may be indicated for patients with head and neck cancer who undergo neck dissections, complain of xerostomia, require feeding tubes, and have medical comorbidities. Treatment of modifiable risk factors such as depression, poor sleep quality, tobacco use, and alcohol abuse may also reduce pain and improve quality of life among patients with head and neck cancer.

Alcohol dependence as a chronic pain disorder

Dysregulation of pain neurocircuitry and neurochemistry has been increasingly recognized as playing a critical role in a diverse spectrum of diseases including migraine, fibromyalgia, depression, and PTSD. Evidence presented here supports the hypothesis that alcohol dependence is among the pathologies arising from aberrant neurobiological substrates of pain. In this review, we explore the possible influence of alcohol analgesia and hyperalgesia in promoting alcohol misuse and dependence. We examine evidence that neuroanatomical sites involved in the negative emotional states of alcohol dependence also play an important role in pain transmission and may be functionally altered under chronic pain conditions. We also consider possible genetic links between pain transmission and alcohol dependence. We propose an allostatic load model in which episodes of alcohol intoxication and withdrawal, traumatic stressors, and injury are each capable of dysregulating an overlapping set of neural substrates to engender sensory and affective pain states that are integral to alcohol dependence and comorbid conditions such as anxiety, depression, and chronic pain.

Painful medical conditions and alcohol use: a prospective study among older adults

OBJECTIVE

To determine associations between older adults' baseline painful medical conditions and their 10-year drinking behavior, and whether personal and life context characteristics moderate these associations.

METHODS

At baseline, then, 1, 4, and 10 years later, late-middle-aged community residents (M = 61 years; N = 1,291) were surveyed regarding their painful medical conditions, use of alcohol, and personal and life context characteristics. Latent growth modeling was used to determine concurrent and prospective relationships between painful medical conditions and 10-year drinking behavior, and moderating effects of personal and life context characteristics on these relationships.

RESULTS

At baseline, individuals reporting more numerous painful medical conditions consumed alcohol less frequently, but had more frequent drinking problems, than did individuals with fewer such conditions. Being female and having more interpersonal social resources strengthened the association between painful medical conditions and less ethanol consumed. For men more so than women, more numerous painful medical conditions were associated with more frequent drinking problems. Baseline painful medical conditions alone had no prospective effect on 10-year change in drinking behavior, but being older and having more interpersonal social resources made it more likely that baseline painful medical conditions would predict decline over time in frequency of alcohol consumption and drinking problems.

CONCLUSIONS

Late-middle-aged individuals who have more numerous painful medical conditions reduce alcohol consumption but nonetheless remain at risk for more frequent drinking problems. Gender, age, and interpersonal social resources moderate the influence of painful medical conditions on late-life alcohol use. These results imply that older individuals with pain are at little immediate or long-term risk for increased alcohol consumption, but clinicians should remain alert to drinking problems among their older pain patients, especially men.