Smoking, tobacco dependence, and neurometabolites in the dorsal anterior cingulate cortex.

Cigarette smoking has a major impact on global health and morbidity, and positron emission tomographic research has provided evidence for reduced inflammation in the human brain associated with cigarette smoking. Given the consequences of inflammatory dysfunction for health, the question of whether cigarette smoking affects neuroinflammation warrants further investigation. The goal of this project therefore was to validate and extend evidence of hypoinflammation related to smoking, and to examine the potential contribution of inflammation to clinical features of smoking. Using magnetic resonance spectroscopy, we measured levels of neurometabolites that are putative neuroinflammatory markers. N-acetyl compounds (N-acetylaspartate + N-acetylaspartylglutamate), glutamate, creatine, choline-compounds (phosphocholine + glycerophosphocholine), and myo-inositol, have all been linked to neuroinflammation, but they have not been examined as such with respect to smoking. We tested whether people who smoke cigarettes have brain levels of these metabolites consistent with decreased neuroinflammation, and whether clinical features of smoking are associated with levels of these metabolites. The dorsal anterior cingulate cortex was chosen as the region-of-interest because of previous evidence linking it to smoking and related states. Fifty-four adults who smoked daily maintained overnight smoking abstinence before testing and were compared with 37 nonsmoking participants. Among the smoking participants, we tested for associations of metabolite levels with tobacco dependence, smoking history, craving, and withdrawal. Levels of N-acetyl compounds and glutamate were higher, whereas levels of creatine and choline compounds were lower in the smoking group as compared with the nonsmoking group. In the smoking group, glutamate and creatine levels correlated negatively with tobacco dependence, and creatine correlated negatively with lifetime smoking, but none of the metabolite levels correlated with craving or withdrawal. The findings indicate a link between smoking and a hypoinflammatory state in the brain, specifically in the dorsal anterior cingulate cortex. Smoking may thereby increase vulnerability to infection and brain injury.

Prospective Effects of UPPS-P Impulsivity and Typical Drinking Context on Future Drinking Behavior.

OBJECTIVE: Research suggests that impulsivity is a risk factor for problem drinking, but prior studies have yet to examine typical drinking context as a potential moderator of relations between impulsivity and drinking outcomes. Guided by Person-Environment Transactions Theory, the current study tested whether five facets of impulsivity (negative urgency, positive urgency, lack of premeditation, lack of perseverance, and sensation seeking) interacted with typical drinking context to prospectively predict drinking quantity. METHOD: Young adult participants (N = 448; mean age = 22.27) were recruited from a southwestern university and the surrounding community. Data from a baseline survey (Time [T] 1) and a 1-year follow-up (T2) were used for the current analyses. Impulsivity (UPPS-P Impulsive Behavior Scale), typical drinking context, and typical drinking quantity were assessed at T1, and typical drinking quantity at T2. RESULTS: Context items were loaded onto latent factors comprising high-arousal (e.g., at a tailgate, large house party) and low-arousal (e.g., at a restaurant, on a date) drinking contexts. In univariate (separated by UPPS-P facet) and multivariate (UPPS-P facets together) models, lack of premeditation and positive urgency interacted with high-arousal drinking contexts to predict T2 drinking, such that individuals at high/mean levels of impulsivity drank more heavily the more frequently they drank in high-arousal contexts. Only interactions in univariate models remained significant after a false discovery correction, although effect sizes were very similar across univariate and multivariate models. CONCLUSIONS: Individuals high in positive urgency and lack of premeditation may be particularly vulnerable to riskier drinking behavior in high-arousal environments. Findings advance the literature on context-specific cues that may be important intervention targets, particularly for individuals high in positive urgency and lack of premeditation.

Putting things in context: Longitudinal relations between drinking contexts, drinking motives, and negative alcohol consequences.

Recent studies suggest that solitary (but not social) drinking may confer risk for negative alcohol consequences via beliefs about alcohol's ability to reduce tension, and explicit motivations to drink to cope with negative mood states. However, because prior studies are largely cross-sectional, it is unclear if tension reduction expectancies and drinking to cope are antecedents or consequences of solitary drinking. The current study aimed to address this gap in the literature using prospective data (3 waves across 12 months) from a sample of moderate to heavy drinking young adults. Data were drawn from a larger investigation of contextual influences on subjective alcohol response. Participants (N = 448) reported on alcohol use in multiple drinking contexts and tension reduction expectancies at baseline (T1), drinking motives at a 6-month follow-up (T2), and past-month negative alcohol consequences at a 12-month follow-up (T3). We examined potential indirect effects of drinking contexts on negative consequences operating through alcohol expectancies and drinking motives. Solitary drinking was indirectly associated with later negative consequences through stronger coping motives, although tension reduction expectancies did not serve as a significant mediator. Social drinking was not directly or indirectly related to later alcohol consequences. Results suggest that solitary drinking contexts confer risk for negative consequences through coping motives, and that these effects are invariant across sex, race, and ethnicity. These findings have important clinical implications as they suggest that targeting solitary drinkers for skills-based coping interventions may reduce risk for a developmental trajectory toward negative alcohol consequences. (PsycInfo Database Record (c) 2021 APA, all rights reserved).