The effect of neuroimmune modulation on subjective response to alcohol in the natural environment

Effects of social drinking context on subjective effects, affect, and next-day appraisals in the natural environment

BACKGROUND

Drinking commonly occurs in social settings and may bolster social reinforcement. Laboratory studies suggest that subjective effects and mood are mechanisms through which the social context influences alcohol consumption. Ecological momentary assessment (EMA) may be useful for extending these findings to the natural environment. This pre-registered secondary analysis of EMA data investigated the influence of the social environment on: (1) stimulating and sedating subjective effects of alcohol, (2) contentedness and negative affect, and (3) next-day evaluations of the drinking occasion.

METHODS

Nontreatment seeking adults reporting past-month heavy drinking (N = 131; Mage = 28.09; 42% female) completed 7 days of EMA (in the morning, at random, and following drinking prompts), which included questions on their social context (drinking in the presence of known others or alone), contemporaneous stimulating and sedating effects, contentedness and negative affect, alcohol consumption, and next-day evaluations of a prior day's drinking event (how satisfying/pleasant was drinking). We used multi-level models in SAS 9.4 M7 software to examine relations among the variables.

RESULTS

Contemporaneous subjective effects (stimulating or sedating), negative affect, and contentedness did not significantly depend on the social context. For next-day evaluations of pleasure/satisfaction from drinking, context effects were dependent on consumption totals. As the total number of standard drinks consumed increased, recollections of pleasure/satisfaction were higher when drinking had occurred with others, relative to alone. At lower consumption totals, next-day evaluations did not appear to depend on social context.

CONCLUSIONS

When reported contemporaneously, subjective effects and affect do not appear dependent upon the presence of known others. However, heavier drinking events, relative to lighter drinking events, are appraised more favorably the following day when occurring within social contexts.

Testing pharmacotherapies for alcohol use disorder with cue exposure paradigms: A systematic review and quantitative synthesis of human laboratory trial methodology

Alcohol cue exposure is a widely used experimental paradigm for screening pharmacotherapies for alcohol use disorder (AUD). Medication-related reductions in cue-reactivity signal early efficacy and inform medications development. Yet, across trials, the design of cue exposure, parameter testing, and outcome reporting is heterogeneous. This systematic review is a quantitative synthesis of trial methodologies and effect size estimation for AUD medication-related craving and psychophysiological outcomes under the cue exposure paradigm. A PubMed search was conducted on January 3, 2022 based on identified pharmacotherapies for peer-reviewed articles reported in English. Study-level characteristics, including sample descriptors, paradigm design, analytic approach, and Cochrane Risk of Bias, along with descriptive statistics for cue-exposure outcomes, were coded by two independent raters. Study-level effect sizes were estimated for craving and psychophysiological outcomes separately and sample-level effect sizes were calculated for each medication. Thirty-six trials, comprising 1640 participants and testing 19 different medications satisfied eligibility criteria. All studies reported on biological sex (71% male participants on average). The exposure paradigms implemented used in vivo (n = 26), visual (n = 8), and audio script (n = 2) cues. Some trials included means for craving by medication condition in text (k = 7) or figures (k = 18). The quantitative synthesis included 63 effect sizes (craving kes  = 47; psychophysiological kes  = 16) from 28 unique randomized trials testing 15 medications for effects on cue reactivity. For cue-induced craving, eight medications (kes range: 1-12) demonstrated small-to-medium effects (Cohen's d range: |0.24-0.64|) compared to placebo, with individuals randomized to receive medication reporting lower craving following cue exposure. Recommendations are provided to promote further consilience, so that the utility of cue exposure paradigms can be maximized in the development of effective AUD pharmacotherapies. Future work should explore the predictive utility of medication-related reductions in cue-reactivity on clinical outcomes.

Baseline C-reactive protein levels are predictive of treatment response to a neuroimmune modulator in individuals with an alcohol use disorder: a preliminary study

Background: Inflammation is implicated in alcohol use disorder (AUD). Ibudilast, a neuroimmune modulator, shows promise for the treatment of AUD. Elevated inflammation, indicated by high levels of C-reactive protein (CRP), represents a possible subtype of AUD, which may be associated with treatment response to ibudilast.Objectives: The current study evaluated CRP as a predictor of treatment response to ibudilast; hypothesizing that ibudilast would be more effective at reducing drinking and alcohol cue-reactivity in individuals with higher CRP levels.Methods: This is a secondary analysis of a clinical trial of ibudilast for AUD, which found that ibudilast reduced heavy drinking in individuals with AUD. Fifty-one individuals were randomized to receive ibudilast (n = 24 [16 M/8F]) or placebo (n = 27 [18 M/9F]) for two weeks. Participants provided blood samples at baseline to assess CRP levels, completed daily assessments of alcohol use, and an fMRI alcohol cue-reactivity task at study mid-point. Models tested the effects of medication, CRP levels, and their interaction on drinks per drinking day and alcohol cue-reactivity.Results: There was a significant interaction between medication and CRP (F = 3.80, p = .03), such that the ibudilast high CRP group had fewer drinks per drinking day compared to the ibudilast low CRP group. CRP moderated the effect of medication on brain activation in a cluster extending from the left inferior frontal gyrus to the right-dorsal striatum (Z = 4.55, p < .001). This interaction was driven by attenuated cue-reactivity in the ibudilast high CRP group relative to the ibudilast low CRP and placebo high CRP groups.Conclusions: This study serves as an initial investigation into predictors of clinical response to ibudilast treatment and suggests that a baseline proinflammatory profile may enhance clinical efficacy.