Nontreatment-seeking Alcoholics Research Articles

Cross-substance primed and cue-induced craving among alcohol and cannabis co-users: An experimental psychopharmacology approach.

Co-use of alcohol and cannabis is highly prevalent and often problematic. However, mechanisms underlying their co-use remain unclear. This randomized and crossover study tests cross-substance subjective craving for alcohol and cannabis. A community sample of nontreatment-seeking alcohol and cannabis co-users (N = 30 completers, 40% female) reporting high-risk levels of alcohol and cannabis use completed two experimental sessions in their homes and were monitored remotely using internet meeting technology (i.e., Zoom). The two counterbalanced and randomized sessions were as follows: (a) consumption of a standard alcoholic beverage followed by cannabis cue exposure and (b) consumption (i.e., smoking) of a miniature cannabis cigarette (containing 18%-22% tetrahydrocannabinol), followed by alcohol cue exposure. Participants rated their subjective craving for both alcohol and cannabis at baseline, following alcohol/cannabis administration, and following the presentation of cross-substance-related cues. Repeated measures analysis of variances revealed a statistically significant difference in cannabis craving across time, such that craving for cannabis was significantly higher following cannabis cue reactivity, compared to baseline and following alcohol administration (p's < .001). Similarly, there was a statistically significant difference in alcohol craving across time, such that craving for alcohol was significantly higher following alcohol cue reactivity, compared to baseline and following cannabis administration (p's < .001). Overall, results suggest that individuals who co-use alcohol and cannabis are most sensitive to the cue-induced, rather than the pharmacologically induced effects, of substance administration on cross-substance craving. This pattern of findings does not support a complementarity model. Conversely, these results may be interpreted as indicative of a substitution model for alcohol and cannabis co-use. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Differences in IV alcohol-induced dopamine release in the ventral striatum of social drinkers and nontreatment-seeking alcoholics

BackgroundStriatal dopamine (DA) has been implicated in alcohol use disorders, but it is still unclear whether or not alcohol can induce dopamine release in social drinkers. Furthermore, no data exist on dopamine responses to alcohol in dependent drinkers. We sought to characterize the DA responses to alcohol intoxication in moderately large samples of social drinkers (SD) and nontreatment-seeking alcoholics (NTS). MethodsTwenty-four SD and twenty-one NTS received two [11C]raclopride (RAC) PET scans; one at rest, and one during an intravenous alcohol infusion, with a prescribed ascent to a target breath alcohol concentration (BrAC), at which it was then “clamped.” The alcohol clamp was started 5min after scan start, with a linear increase in BrAC over 15min to the target of 80mg%, the legal threshold for intoxication. Target BrAC was maintained for 30min. Voxel-wise binding potential (BPND) was estimated with MRTM2. ResultsIV EtOH induced significant increases in DA in the right ventral striatum in NTS, but not SD. No decreases in DA were observed in either group. ConclusionsAlcohol intoxication results in distinct anatomic profiles of DA responses in SD and NTS, suggesting that in NTS, the striatal DA system may process effects of alcohol intoxication differently than in SD.

Monetary discounting and ventral striatal dopamine receptor availability in nontreatment-seeking alcoholics and social drinkers.

Dopamine (DA) in the ventral striatum (VST) has long been implicated in addiction pathologies, yet its role in temporal decision-making is not well-understood. To determine if VST DA D2 receptor availability corresponds with greater impulsive choice in both nontreatment-seeking alcoholics (NTS) and social drinkers (SD). NTS subjects (n = 10) and SD (n = 13) received PET scans at baseline with the D2/D3 radioligand [(11)C]raclopride (RAC). Outside the scanner, subjects performed a delay discounting procedure with monetary rewards. RAC binding potential (BPND) was estimated voxelwise, and correlations were performed to test for relationships between VST BPND and delay discounting performance. Self-reported impulsivity was also tested for correlations with BPND. Across all subjects, greater impulsive choice for $20 correlated with lower BPND in the right VST. NTS showed greater impulsive choice than SD and were more impulsive by self-report. Across all subjects, the capacity of larger rewards to reduce impulsive choice (the magnitude effect) correlated negatively (p = 0.028) with problematic alcohol use (AUDIT) scores. Self-reported impulsivity did not correlate with BPND in VST. Preference for immediate reinforcement may reflect greater endogenous striatal DA or lower D2 number, or both. Alcoholic status did not mediate significant effects on VST BPND, suggesting minimal effects from alcohol exposure. The apparent lack of BPND correlation with self-reported impulsivity highlights the need for objective behavioral assays in the study of the neurochemical substrates of behavior. Finally, our results suggest that the magnitude effect may be more sensitive to alcohol-induced problems than single discounting measures.

Naltrexone Modification of Drinking Effects in a Subacute Treatment and Bar‐Lab Paradigm: Influence of OPRM1 and Dopamine Transporter (SLC6A3) Genes

Naltrexone is moderately effective for the treatment of alcohol dependence, but there is great individual variability. The opioid receptor (OPRM1) single nucleotide polymorphism (SNP) asn40asp has been shown to alter alcohol and naltrexone response in animals and humans. In addition, the brain opioid and dopamine systems interact and might underlie drinking and craving. This study investigated the effects of the OPRM1 SNP and dopamine transporter (DAT) variable number of tandem repeat (VNTR) genetic differences on drinking, alcohol effects, and naltrexone response under controlled conditions in nontreatment-seeking alcoholics. Two hundred and sixty-five nontreatment-seeking individuals with alcohol dependence were genotyped a priori for the OPRM1 asn40asp SNP and post hoc for DAT (SLC6A3) 9 and 10 VNTRs. Asp40 carriers (n=43) and matched asn40 homozygotes (n=40) were randomized to naltrexone or placebo for 7days before receiving a priming drink and limited-access alcohol consumption in a bar-lab setting. Effects of genotypes on natural drinking as well as drinking, alcohol effects, and response to naltrexone in the bar-lab setting were examined by genotype. There were no significant main effects of naltrexone or OPRM1 genotype, or any medication by OPRM1 interaction, on drinking variables. However, in individuals who had at least one DAT 9 VNTR, and who were also OPRM1 asn40 homozygotes, naltrexone reduced drinks/d consumed under natural conditions (p=0.006), but not in the bar-lab. OPRM1 asn40 homozygotes (p=0.028) and DAT 9 VNTR carriers (p=0.032) had more stimulation to alcohol after the priming drink. This study does not support a salient role for the OPRM1 asp40 alone in predicting drinking or naltrexone effects. However, although exploratory and in need of replication, it introduces the possibility that epistasis between the OPRM1 gene and DAT gene might need to be taken into account when examining differential genetic response to alcohol or medication treatment, especially in early-stage alcoholics.

Test–retest variability of [11C]raclopride‐binding potential in nontreatment‐seeking alcoholics

Knowledge of the reproducibility of striatal [¹¹C]raclopride (RAC) binding is important for studies that use RAC PET paradigms to estimate changes in striatal dopamine (DA) during pharmacological and cognitive challenges. To our knowledge, no baseline test-retest data exist for nontreatment-seeking alcoholics (NTS). We determined the test-retest reproducibility of baseline RAC binding potential (BP(ND) ) in 12 male NTS subjects. Subjects were scanned twice with single-bolus RAC PET on separate days. Striatal RAC BP (BP(ND) ) for left and right dorsal caudate, dorsal putamen, and ventral striatum was estimated using the Multilinear Reference Tissue Method (MRTM) and Logan Graphical Analysis (LGA) with a reference region. Test-retest variability (TRV), % change in BP(ND) between scan days, and the intraclass correlation coefficient (ICC) were used as metrics of reproducibility. For MRTM, TRV for striatal RAC binding in NTS subjects was ±6.5% and ±7.1% for LGA. Average striatal ICCs were 0.94 for both methods (P < 0.0001). Striatal BP(ND) values were similar to those reported previously for detoxified alcoholics. The results demonstrate that baseline striatal RAC binding is highly reproducible in NTS subjects, with a low variance similar to that reported for healthy control subjects.