Is (poly-) substance use associated with impaired inhibitory control? A mega-analysis controlling for confounders.

Many studies have reported that heavy substance use is associated with impaired response inhibition. Studies typically focused on associations with a single substance, while polysubstance use is common. Further, most studies compared heavy users with light/non-users, though substance use occurs along a continuum. The current mega-analysis accounted for these issues by aggregating individual data from 43 studies (3610 adult participants) that used the Go/No-Go (GNG) or Stop-signal task (SST) to assess inhibition among mostly "recreational" substance users (i.e., the rate of substance use disorders was low). Main and interaction effects of substance use, demographics, and task-characteristics were entered in a linear mixed model. Contrary to many studies and reviews in the field, we found that only lifetime cannabis use was associated with impaired response inhibition in the SST. An interaction effect was also observed: the relationship between tobacco use and response inhibition (in the SST) differed between cannabis users and non-users, with a negative association between tobacco use and inhibition in the cannabis non-users. In addition, participants' age, education level, and some task characteristics influenced inhibition outcomes. Overall, we found limited support for impaired inhibition among substance users when controlling for demographics and task-characteristics.

Child and adolescent predictors of smoking involvement in emerging adulthood.

OBJECTIVE: This study examined the differential relationship of externalizing behavior, internalizing behavior, social context, and their interactions to three developmental indicators of smoking involvement: onset (age), amount of smoking, and dependence symptomatology. METHOD: Participants (n = 504, 73% male) from a high-risk community-based longitudinal study were followed from age 12-14 to young adulthood (18-20). Smoking involvement was conceptualized as a process involving differences in (a) age of onset of smoking, (b) amount of smoking at age 18-20, and (c) level of nicotine dependence symptomatology at age 18-20. Survival analysis was used to predict onset of smoking, regression for smoking level, and zero-inflated Poisson regression for nicotine dependence. RESULTS: Externalizing (teacher report) and internalizing behavior (youth self-report), prior to the onset of smoking, predicted different components of smoking and nicotine dependence in young adulthood. Parental smoking predicted all levels of smoking involvement. Peer smoking was related to early onset of smoking, but not higher levels of smoking involvement. Externalizing and internalizing behavior interacted to predict nicotine dependence level, with higher levels of internalizing behavior predicting higher levels of dependence symptoms, even at low levels of externalizing behavior. CONCLUSIONS: Externalizing and internalizing behavior and social context are independent and interacting risk factors that come into play at different points in the developmental process occurring between smoking onset and dependence. This study provides important information for theoretical models of smoking progression and shows that different types of risk should be targeted for prevention at different points in smoking progression. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Childhood adversity, externalizing behavior, and substance use in adolescence: Mediating effects of anterior cingulate cortex activation during inhibitory errors.

Childhood adversity can negatively impact development across various domains, including physical and mental health. Adverse childhood experiences have been linked to aggression and substance use; however, developmental pathways to explain these associations are not well characterized. Understanding early precursors to later problem behavior and substance use can inform preventive interventions. The aim of the current study was to examine neurobiological pathways through which childhood adversity may lead to early adolescent problem behavior and substance use in late adolescence by testing two prospective models. Our first model found that early adolescent externalizing behavior mediates the association between childhood adversity and alcohol, cigarette, and marijuana use in late adolescence. Our second model found that activation in the anterior cingulate cortex (ACC) during an inhibitory control task mediates the association between childhood adversity and early adolescent externalizing behavior, with lower ACC activation associated with higher levels of adversity and more externalizing behavior. Together these findings indicate that the path to substance use in late adolescence from childhood adversity may operate through lower functioning in the ACC related to inhibitory control and externalizing behavior. Early life stressors should be considered an integral component in the etiology and prevention of early and problematic substance use.

Body mass index across adolescence and substance use problems in early adulthood.

Excessive substance use and obesity are underpinned by a number of shared risk factors (e.g., reward dysfunction, impulsivity). Food and drugs of abuse engage similar reward-related neural circuitry and the food-drug competition hypothesis proposes that excess consumption of food may diminish desire for drugs of abuse by competing for neural receptors associated with reward and motivation. Adolescence is a high-risk period for both increased substance use and excessive weight gain. In the present study, the authors tested whether, consistent with the food-drug competition hypothesis, elevated body mass index (BMI) across adolescence predicted fewer substance use problems in young adulthood. In a multiwave prospective study of a community sample of families enriched for high levels of substance use disorders, the authors first identified BMI trajectories across adolescence in 565 participants using latent class growth analysis. They then used maximum likelihood methods to compare the equality of mean alcohol-, drug-, and nicotine-related problems during early adulthood across adolescent BMI trajectories. Participants in the obese relative to the normal weight trajectory in adolescence had fewer drinking and illicit drug problems in early adulthood. Relative to the overweight trajectory, nicotine dependence was significantly higher among both the normal weight and obese trajectories. The current findings provide partial support for the food-drug competition hypothesis, which suggests that highly palatable foods may be rewarding enough to compete with drugs of abuse and that transdiagnostic approaches to reducing problematic substance use and overeating in adolescence may be useful. However, the relationship between nicotine and food requires further study. (PsycINFO Database Record

Association of Marijuana Use With Blunted Nucleus Accumbens Response to Reward Anticipation.

IMPORTANCE: Marijuana use may alter ventral striatal response to reward, which might heighten susceptibility to substance use disorder. Longitudinal research is needed to determine the effects of marijuana use on neural function involved in reward response. OBJECTIVE: To determine whether marijuana use among young adults prospectively affects nucleus accumbens (NAcc) activation during reward anticipation. DESIGN, SETTING, AND PARTICIPANTS: One hundred eight young adults were recruited from the Michigan Longitudinal Study, an ongoing study of youth at high risk for substance use disorder and a contrast sample of control families. Participants underwent 3 consecutive functional magnetic resonance imaging scans at approximate ages of 20 (time 1), 22 (time 2), and 24 (time 3) years. Self-report data on marijuana and other drug use occasions were collected annually since age 11 years. MAIN OUTCOMES AND MEASURES: Cross-lagged models were used to test the association of marijuana use with neural response in the NAcc to reward anticipation during a monetary incentive delay task controlling for sex, age, other substance use, and family history of substance use disorder. RESULTS: Of 108 participants, 39 (36.1%) were female and mean (SD) age at baseline was 20.1 (1.4) years. Greater marijuana use was associated with later blunted activation in the NAcc during reward anticipation (time 1 to time 2: ß = -0.26, P = .04; time 2 to time 3: ß = -0.25, P = .01). When the cross-lagged model was tested with the inclusion of previous and concurrent cigarette use, the effect of marijuana use from time 2 to time 3 remained significant (ß = -0.29; P = .005) and the effect of cigarette use was nonsignificant. CONCLUSIONS AND RELEVANCE: The findings of this study indicate that marijuana use is associated with decreased neural response in the NAcc during the anticipation of nondrug rewards. Over time, marijuana use may alter anticipatory reward processing in the NAcc, which may increase the risk for continued drug use and later addiction.

The Relationships of Cigarette and Alcohol Use With the Initiation, Reinitiation, and Persistence of Cannabis Use.

OBJECTIVE: This study used a prospective survey to examine (a) the relationships of early onset and prior consumption of cannabis, cigarette, and alcohol use with later cannabis use initiation, reinitiation, and persistence; and (b) whether the quantity or frequency of alcohol or cigarette use was more predictive of cannabis use initiation, reinitiation, or persistence. METHOD: This study used data from the National Epidemiologic Survey of Alcohol and Related Conditions, Wave 1 (2001-2002) and Wave 2 (2004-2005), including 27,741 nonusers, 5,623 prior users, and 1,279 current cannabis users at baseline who were at risk of cannabis use initiation, reinitiation, and persistence, respectively, between baseline and follow-up assessments. We employed logistic regression to examine the effects of prior substance use on cannabis use initiation, reinitiation, and persistence, controlling for sociodemographics. RESULTS: Frequency and early-onset status of cigarette use (≤14 years) and alcohol use (≤17 years) predicted cannabis use initiation and reinitiation but not persistence. While considering the potential effects of early onset and consumption levels of cannabis use, baseline alcohol and cigarette use quantity and frequency did not predict persistent cannabis use. Frequency, compared with quantity, of alcohol and cigarette use was more predictive of cannabis use initiation and reinitiation. CONCLUSIONS: Early onset and prior experience with cannabis, cigarettes, and alcohol could have effects on later cannabis use, varying among the three at-risk populations. Different strategies are needed for preventing cannabis use initiation, reinitiation, and persistence, based on targeting early use of alcohol and cigarettes.

Gender differences in the developmental risk of onset of alcohol, nicotine, and marijuana use and the effects of nicotine and marijuana use on alcohol outcomes.

OBJECTIVE: This study aimed to (a) characterize gender-specific risk of onset of alcohol, nicotine, and marijuana use developmentally; (b) investigate the effects of early-onset status and frequency of nicotine and marijuana use on alcohol outcomes, controlling for the effects of alcohol use; and (c) examine gender differences in the developmental trajectories of alcohol outcomes and the effects of nicotine and marijuana use on alcohol outcomes. METHOD: This study conducted secondary analysis on a longitudinal study that recruited at-risk youth through fathers' drunk-driving records and door-to-door canvassing in the midwestern United States. The sample included 160 female-male sibling pairs who were assessed on substance use and Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, diagnosis from early childhood to young adulthood. RESULTS: Although males were at higher risk for being early-onset alcohol users, females tended to be at higher risk for initiating marijuana use at younger ages. When early onset and amount of alcohol use were controlled for, early onset of nicotine and marijuana use did not contribute to alcohol outcomes, but frequencies of nicotine and marijuana use did. We also found the associations of quantity/frequency of alcohol and marijuana use with drinking problems to be stronger among females than among males. CONCLUSIONS: Higher frequencies of nicotine and marijuana use may contribute to worse alcohol outcomes above and beyond the effect of alcohol use. Females tend to be at higher risk than males for initiating marijuana use and meeting an alcohol use disorder diagnosis at younger ages as well as being more vulnerable to a negative impact of alcohol and marijuana use.

Effects of alcoholism severity and smoking on executive neurocognitive function.

AIMS: Neurocognitive deficits in chronic alcoholic men are well documented. Impairments include memory, visual-spatial processing, problem solving and executive function. The cause of impairment could include direct effects of alcohol toxicity, pre-existing cognitive deficits that predispose towards substance abuse, comorbid psychiatric disorders and abuse of substances other than alcohol. Cigarette smoking occurs at higher rates in alcoholism and has been linked to poor cognitive performance, yet the effects of smoking on cognitive function in alcoholism are often ignored. We examined whether chronic alcoholism and chronic smoking have effects on executive function. METHODS: Alcoholism and smoking were examined in a community-recruited sample of alcoholic and non-alcoholic men (n = 240) using standard neuropsychological and reaction-time measures of executive function. Alcoholism was measured as the average level of alcoholism diagnoses across the study duration (12 years). Smoking was measured in pack-years. RESULTS: Both alcoholism and smoking were correlated negatively with a composite executive function score. For component measures, alcoholism was correlated negatively with a broad range of measures, whereas smoking was correlated negatively with measures that emphasize response speed. In regression analyses, both smoking and alcoholism were significant predictors of executive function composite. However, when IQ is included in the regression analyses, alcoholism severity is no longer significant. CONCLUSIONS: Both smoking and alcoholism were related to executive function. However, the effect of alcoholism was not independent of IQ, suggesting a generalized effect, perhaps affecting a wide range of cognitive abilities of which executive function is a component. On the other hand, the effect of smoking on measures relying on response speed were independent of IQ, suggesting a more specific processing speed deficit associated with chronic smoking.

Smoking is associated with neurocognitive deficits in alcoholism.

BACKGROUND: Impaired problem solving, visual-spatial processing, memory, and cognitive proficiency are consequences of severe alcoholism. Smoking is much more prevalent among alcoholics than the general population, yet the possible neurocognitive effects of cigarette smoking in alcoholism have not been studied, despite evidence that long-term smoking is associated with neurocognitive deficits. OBJECTIVE: Determine whether smoking contributes to neurocognitive deficits associated with alcoholism. DESIGN: Neurocognitive function was examined in a community-recruited (n=172) sample of men. Alcohol problems/alcoholism were measured by the lifetime alcohol problems score (LAPS), DSM-IV diagnosis, and monthly drinking rate. Smoking was measured in pack-years. Neurocognitive function was measured with IQ (short version of WAIS-R), and cognitive proficiency (fast, accurate performance). RESULTS: Both alcoholism and smoking were negatively correlated with neurocognitive function. When alcoholism and smoking were included in regression models, smoking remained a significant predictor for both measures, but alcoholism remained significant only for IQ. CONCLUSIONS: Both smoking and alcoholism were related to neurocognitive function. Smoking may explain some of the relationship between alcoholism and neurocognitive function, perhaps especially for measures that focus on proficiency. Future studies are necessary to more fully understand the effects of smoking on neurocognitive function in alcoholism.