Modeling alcohol use disorder severity: an integrative structural equation modeling approach

Alcohol use disorder severity moderates clinical response to varenicline

BACKGROUND

In a multisite clinical trial, varenicline was effective in reducing drinking in both smoking and non-smoking patients with alcohol dependence. Because alcohol use disorder (AUD) is heterogeneous, research aimed at characterizing features associated with treatment response could advance personalized pharmacotherapy. The current study examined the utility of a multidimensional assessment of AUD severity to identify responders to varenicline treatment.

METHODS

The study utilized data from a 13-week, Phase 2, randomized, double-blind, placebo-controlled, multisite trial of varenicline in 200 alcohol-dependent patients. Four hypothesized measures of AUD severity (i.e., DSM-IV criterion count, withdrawal, craving, and alcohol-related consequences) were combined into a single severity factor. A series of multilevel models that included the severity factor were conducted to examine its effects on treatment outcomes.

RESULTS

All hypothesized indices of AUD severity loaded significantly onto a singular severity factor. Among low-severity groups, varenicline treatment significantly reduced drinking (i.e., percent heavy drinking days, drinks per day, and drinks per drinking day) and, in the lowest severity group, it improved the mental health component of quality of life more than placebo. The most severe group showed no differences between the varenicline and placebo groups on drinking or quality of life measures.

CONCLUSIONS

Treatment response to varenicline may be greater among individuals with less-severe AUD, as evidenced by both reductions in drinking outcomes and improvements in psychosocial functioning.

Preliminary study of alcohol problem severity and response to brief intervention

Background

Findings have been mixed as to whether brief intervention (BI) is appropriate and effective for individuals with more severe alcohol use problems. Motivation to change drinking has been supported as a mechanism of behavior change for BI. This exploratory study examined aspects of motivation as mechanisms of clinical response to BI and alcohol problem severity as a moderator of treatment effects.

Methods

Non-treatment-seeking heavy drinkers (average age = 35 years; 57% male) were randomized to receive BI (n = 27) or attention-matched control (n = 24). Three indices of motivation to change were assessed at baseline and post-intervention: importance, confidence, and readiness. Moderated mediation analyses were implemented with treatment condition as the focal predictor, changes in motivation as mediator, 1-month follow-up drinks per day as the outcome, and an alcohol severity factor as second-stage moderator.

Results

Analysis of importance displayed a significant effect of intervention condition on importance (p < 0.003) and yielded a significant index of moderated mediation (CI − 0.79, − 0.02), indicating that the conditional indirect effect of treatment condition on drinking through importance was stronger for those with higher alcohol severity. For all motivation indices, alcohol severity moderated the effect of post-intervention motivation levels on drinking (p’s < 0.05). The direct effect of treatment condition on drinking was not significant in any model.

Conclusions

Findings highlight the relevance of considering one’s degree of alcohol problem severity in BI and alcohol screening efforts among non-treatment seeking heavy drinkers. These nuanced effects elucidate both potential mechanisms and moderators of BI response.

Trial registration Clinicaltrials.gov: NCT04710095. Registered January 14, 2021—retrospectively registered, https://clinicaltrials.gov/ct2/show/study/NCT04710095.

Lifetime heavy drinking years predict alcohol use disorder severity over and above current alcohol use

Background: Preclinical studies demonstrate that chronic and heavy alcohol use facilitates neuroadaptations that perpetuate addiction-like behaviors. In clinical studies, it is unclear whether the extent of heavy alcohol use over the lifetime contributes to alcohol use disorder (AUD) severity over and above current alcohol use patterns (i.e. last 30 days to 3-months). Such information may improve our understanding of the phenomenology of AUD.Objectives: The purpose of this study was to examine lifetime heavy drinking years in relation to a clinical assessment of AUD.Methods: Participants, who were non-treatment-seeking and engaged in heavy drinking (n = 140; 50% male), completed an interview-based assessment of lifetime regular and heavy drinking years along with a battery of measures indexing alcohol use and problems, drinking motives, and depression and anxiety symptomatology.Results: Lifetime heavy drinking years was positively associated with lifetime regular drinking years, current alcohol use, alcohol problems, tonic alcohol craving, drinking for the enhancing effects of alcohol, and drinking to cope (r's = .21-.58). Adjusting for lifetime regular drinking years and current alcohol use, lifetime heavy drinking years predicted higher scores on the Alcohol Use Disorder Identification Test (AUDIT; B = .382; SE = .123). A multivariate logistic regression found that lifetime heavy drinking years predicted greater odds of more severe AUD over and above current alcohol use (OR = 1.147).Conclusion: Our findings suggest that lifetime heavy drinking years are a clinically meaningful indicator of AUD severity that is not redundant with current alcohol use measures.

Evaluation of the Addictions Neuroclinical Assessment (ANA) framework through deep phenotyping of problem drinkers

BACKGROUND

To advance the development of a neuroscience-informed understanding of alcohol use disorder (AUD) through the Addictions Neuroclinical Assessment (ANA) framework, the present study reports on deep phenotyping of a large sample of problem drinkers.

METHODS

Participants (n = 1679) were primarily heavy drinkers with and without AUD, who completed a phenotypic battery of well-validated scales and behavioral measures of alcohol use and problems, mood, attention, and impulsivity. These scales were subjected to sequential factor analytic work in order to derive a factor solution that explains biobehavioral variation in the sample. To assess the construct validity of the resulting factor solution, scores on each factor were associated with demographic and clinical indicators.

RESULTS

Factor analysis techniques using indicators of alcohol use and problems, mood, attention, and impulsivity implicated four functional domains that compliment and extend the proposed ANA domains: negative alcohol-related consequences, incentive salience, negative emotionality, and executive function. Demographic and clinical variables significantly predicted scores on all ANA domains.

CONCLUSIONS

This study provides an independent test of the recently proposed neuroscience-based ANA framework. Results largely support the novel approach in identifying four core constructs in problem drinkers. Future studies can deepen our understanding of how these domains are relevant to AUD by incorporating biomarkers.

Neurocognitive performance in alcohol use disorder using the NIH toolbox: Role of severity and sex differences

AIMS

Sustained heavy alcohol consumption is associated with a range of neurocognitive deficits. Yet, past research centers on a severe profile of alcohol use disorder (AUD), with persons recruited from in-patient settings. The current project aims to compare neurocognitive performance between individuals seeking AUD outpatient treatment with healthy comparisons while considering the association between performance, disorder severity, and sex.

METHODS

Enrollment included two matched groups (N = 125; 34 % female): 77 treatment-seeking individuals with AUD; 48 healthy comparison individuals with low drinking patterns. Neurocognitive performance on NIH Toolbox subtests measuring attention, inhibition, episodic memory, working memory, language, and processing speed were compared across groups. Within the AUD group, analyses examined the relationship between performance, disorder severity, recent alcohol consumption, and sex.

RESULTS

AUD group did not perform significantly lower than healthy comparisons on neurocognition subtests assessed. Within AUD group, females displayed significantly higher processing speeds than males (p = .007). Disorder severity and alcohol consumption were not significantly related to performance. However, a significant interaction between disorder severity and sex emerged (p = .010), with higher severity associated with poorer performance in males but not females, on a subtest measuring attention and inhibition.

CONCLUSIONS

Effect of heavy alcohol use on neurocognitive performance was not detected in this outpatient AUD sample. Weaknesses in domains of attention and inhibition may be correlated with AUD severity among males, but not females. Further research on AUD severity and sex in understanding individual differences in neurocognition is warranted, particularly using novel tools for large scale phenotyping, such as the NIH Toolbox.

The Association Between Alcohol Consumption and Pain Interference in a Nationally Representative Sample: The Moderating Roles of Gender and Alcohol Use Disorder Symptomatology

BACKGROUND

Prior research on alcohol consumption and pain has yielded inconsistent results regarding the directionality of effects for both consumption-to-pain and pain-to-consumption relations. The present study sought to examine directionality of these relations by testing bidirectional longitudinal associations between consumption and pain interference, a crucial aspect of pain that captures pain-related disability and has been regarded as a valuable measure of treatment outcome. In addition, this study explored possible moderation of these bidirectional longitudinal associations by gender and alcohol use disorder (AUD) symptomatology.

METHODS

Analyses included 29,989 current/former drinkers who were interviewed at both waves (2001 and 2004) of the U.S. National Epidemiological Survey on Alcohol and Related Conditions (NESARC). Analyses used self-report data from both waves on past-year average daily volume of alcohol consumed and past-month pain interference (1 item from the Medical Outcomes Study 12-item Short-Form Health Survey [MOS-SF-12]). AUDADIS-IV data from Wave 1 were used to index baseline AUD symptomatology (i.e., symptom count). Cross-lagged panel modeling and multigroup analyses were employed.

RESULTS

Regarding the consumption-to-pain-interference relation, in general, higher baseline alcohol consumption was associated with lower subsequent pain interference at follow-up. However, among men with higher AUD-symptom counts, the opposite pattern emerged, with higher baseline alcohol consumption being significantly related to higher subsequent pain interference at follow-up. Regarding the pain-interference-to-consumption relation, higher baseline pain interference was significantly associated with lower subsequent alcohol consumption at follow-up, and no moderating effects were observed.

CONCLUSIONS

The distinctive patterns of the consumption-to-pain-interference relation observed among men with elevated AUD symptomatology suggest that this relation might be driven by different mechanisms across different groups of individuals. Specifically, the detrimental effect of alcohol on pain interference might emerge at relatively advanced stages of AUD among men, consistent with Koob's Dark Side of Alcohol Addiction theory in human research.

A rapid access to addiction medicine clinic facilitates treatment of substance use disorder and reduces substance use

Background

Substance use is prevalent in Canada, yet treatment is inaccessible. The Rapid Access to Addiction Medicine (RAAM) clinic opened at the University Health Network (UHN) in January 2018 as part of a larger network of addictions clinics in Toronto, Ontario, to enable timely, low barrier access to medical treatment for substance use disorder (SUD). Patients attend on a walk-in basis without requiring an appointment or referral. We describe the RAAM clinic model, including referral patterns, patient demographics and substance use patterns. Secondary outcomes include retention in treatment and changes in both self-reported and objective substance use.

Methods

The Electronic Medical Record at the clinic was reviewed for the first 26 weeks of the clinic’s operation. We identified SUD diagnoses, referral source, medications prescribed, retention in care and self-reported substance use.

Results

The clinic saw 64 unique patients: 66% had alcohol use disorder (AUD), 39% had opiate use disorder (OUD) and 20% had stimulant use disorder. Fifty-five percent of patients were referred from primary care providers, 30% from the emergency department and 11% from withdrawal management services. Forty-two percent remained on-going patients, 23% were discharged to other care and 34% were lost to follow-up. Gabapentin (39%), naltrexone (39%), and acamprosate (15%) were most frequently prescribed for AUD. Patients with AUD reported a significant decrease in alcohol consumption at their most recent visit. Most patients (65%) with OUD were prescribed buprenorphine, and most patients with OUD (65%) had a negative urine screen at their most recent visit.

Conclusion

The RAAM model provides low-barrier, accessible outpatient care for patients with substance use disorder and facilitates the prescription of evidence-based pharmacotherapy for AUD and OUD. Patients referred by their primary care physician and the emergency department demonstrated a reduction in median alcohol consumption and high rates of opioid abstinence.

The effect of alcohol priming on neural markers of alcohol cue-reactivity

BACKGROUND

Priming doses of alcohol are associated with increased desire to drink and disinhibitory effects on subsequent control over drinking. Despite the importance of alcohol priming in the cue-reactivity literature, the effects of priming on brain responses to alcohol cues remains unclear. Furthermore, evidence suggests this relationship may be moderated by OPRM1 genotype.

METHODS

Twenty individuals with alcohol dependence (six females; 90% Caucasian; mean age = 29.4) who were prospectively genotyped on the OPRM1 gene underwent two functional magnetic resonance imaging (fMRI) sessions, before and after a priming dose of alcohol, each including a gustatory alcohol cue reactivity paradigm and self-reported craving measures.

RESULTS

Self-reported alcohol craving generally increased and remained higher for alcohol versus water cue presentations across pre- and post-priming scans. Compared to alcohol cues delivered during the post-priming scan, alcohol cues delivered pre-priming were associated with greater activation in regions including the hippocampus, amygdala, inferior frontal gyrus, temporal cortex, and occipital cortex. Controlling for alcoholism severity increased statistical significance of activation in these regions. Follow-up analyses revealed a positive correlation between alcoholism severity and pre- versus post-priming alcohol cue-reactivity primarily in frontal regions. OPRM1 genotype was also found to moderate alcohol cue-reactivity across scans.

CONCLUSION

This study provides initial evidence of alcohol cue-elicited habituation in fronto-temporal regions, despite continued craving, following a priming dose of alcohol. Further, it provides preliminary evidence for moderating roles of alcoholism severity and OPRM1 genotype on priming-related changes in cue-reactivity, adding to our understanding of the function of alcohol priming in alcohol dependence.