Trajectories of impulsivity by sex predict substance use and heavy drinking

Do Individuals with Internet Gaming Disorder Share Personality Traits with Substance-Dependent Individuals?

(1) Background: Internet gaming disorder (IGD) shares many similarities with substance use disorder (SUD), contributing to its recognition as an addictive disorder. Nevertheless, no study has compared IGD to other addictive disorders in terms of personality traits established as highly co-occurring with SUDs. (2) Methods: We recruited a sample of gamers (massively multiplayer online role-playing games) (MMORPGs) via online in-game forums. We compared 83 individuals with IGD (MMORPG-IGD group) to 47 former heroin addicts under methadone maintenance treatment (MMT; MMT group) with regard to alexithymia, impulsivity, sensation seeking and aggressiveness assessed through self-administered scales, being TAS-20, BIS-10, Z-SSS and BDHI, respectively. (3) Results: Our results draw a relatively similar personality profile between groups but indicate that the subject traits are generally more pronounced in the MMT cohort. The overall lesser intensity of these traits in the MMORPG-IGD group might reflect the greater variability in the severity of the IGD. (4) Conclusions: IGD shares personality traits with MMT, and intensity may be influenced by the severity of the addiction or by certain direct environmental factors, and might also influence the propensity towards one behavior rather than another.

The moderating role of positive peers in reducing substance use in college students

ObjectiveYoung adulthood (18-25) is the peak age for substance use, but friends who engage in positive behaviors may be protective. The present study examined the direct relation between positive peer affiliation and substance use, and whether positive peer affiliation moderated the relation between self-reported sensation-seeking, future orientation, self-regulation and substance use. Participants: Participants were 382 college students (M_age = 19.25, SD = 1.33). Method: Participants completed questionnaires assessing substance use, peer affiliation, sensation-seeking, future orientation, and self-regulation. Results: In structural equation models, positive peer affiliation was negatively associated with drunk driving, cigarette use, and marijuana use; and moderated relations between sensation-seeking and substance use, but not cognitive control in the predicted direction. Conclusions: Substance use remains a salient public health concern for college students, but the current study found that having friends who generally engage in positive activities is an important buffer against socioemotional risk factors.

Is E-cigarette Use Associated With Persistence or Discontinuation of Combustible Cigarettes? A 24-Month Longitudinal Investigation in Young Adult Binge Drinkers

INTRODUCTION

It remains unclear whether electronic cigarette (e-cigarette) use promotes persistent combustible tobacco use or smoking discontinuation over time. Alcohol use is associated with a greater risk of adverse health effects of tobacco, and higher likelihood of e-cigarette use, making drinkers a high-priority subpopulation.

AIMS AND METHODS

This study examined longitudinal patterns of combustible tobacco and e-cigarette use over 24 months in young adult binge drinkers. A pooled dataset of 1002 (58.5% female; M age = 22.14) binge drinkers from the United States (60%) and Canada (40%) was used. The primary outcomes were past month combustible tobacco and e-cigarette use. Nicotine dependence was measured using the Fagerström Test of Cigarette Dependence. Alcohol severity was measured using the Young Adult Alcohol Consequences Questionnaire. Latent transition analysis (LTA) was used to identify patterns of cigarette smoking and e-cigarette use over 24 months.

RESULTS

The LTA yielded a four-class solution: (1) e-cigarettes-only users (prevalence over time: 7.75%-10.10%), (2) dual-product users (2.61%-9.89%), (3) combustible-only smokers (8.12%-20.70%), and (4) nonusers (61.66%-80.06%). Dual-product users predominantly transitioned to complete abstinence or exclusively e-cigarette use. In combustible-only smokers, the most common transition was to abstinence, followed by persistence of combustible-only status. At 24 months, 63% of e-cigarettes-only users transitioned to abstinence, with 37% continuing e-cigarettes-only use and 0% transitioning to dual or combustible cigarette use.

CONCLUSIONS

Dual-product use in young adult binge drinkers was associated with discontinuation of combustible tobacco over time, and e-cigarette-only use was not associated with subsequent combustible tobacco use.

IMPLICATIONS

These findings suggest that concurrent or exclusive e-cigarette use is not a risk factor for the persistence or development of combustible tobacco use in this subpopulation, with dual-product use reflecting a transitional pattern away from combustible use, toward discontinuation.

Effects of Risk Perception and Accessibility on Cannabis Use among Young Population in Spain: Findings from the 2016 National Survey (ESTUDES)

BackgroundCannabis use in the young population has undergone a significant increase in Europe. Empirical assessments of individual and contextual mediating variables in relation to cannabis use are informative for prevention actions and have yet to be conducted in Spain. Objectives: This study used the 2016 National Survey on Drug Use in Secondary Education in Spain (ESTUDES) to inform on potentially relevant cannabis prevention targets. We examined individual variables (sex, age, and cannabis risk perception), past 30-day legal and illicit substance use, substance-free activities, and contextual factors (perceived accessibility to cannabis) associated to past 30-day cannabis use. Methods: Data were drawn from 35,369 adolescents (% females: 50.1). Structural equation modeling (SEM) was implemented to identify predictors of cannabis use, and indirect paths were tested via bootstrapping to examine the mediating effects of cannabis risk perception and accessibility. Results: Demographics (male sex, higher age), and past 30-day tobacco, alcohol, and illicit substance use were associated with past 30-day cannabis use. Frequency of past-year engagement in hobbies and reading did also predict past 30-day cannabis use. The mediators worked on most of the relationships examined, except for hobbies and illegal substance use in the case of accessibility and reading and hobbies in the case of risk perception. Conclusions/importance: Cannabis use is more likely to emerge in the event of low risk perception and high accessibility. Lower frequency of past year reading and higher engagement in some hobbies that are often carried out alone represent risk factors, which could potentially influence prevention programs.

Which came first: Cannabis use or deficits in impulse control?

Impulse control deficits are often found to co-occur with substance use disorders (SUDs). On the one hand, it is well known that chronic intake of drugs of abuse remodels the brain with significant consequences for a range of cognitive behaviors. On the other hand, individual variation in impulse control may contribute to differences in susceptibility to SUDs. Both of these relationships have been described, thus leading to a "chicken or the egg" debate which remains to be fully resolved. Does impulsivity precede drug use or does it manifest as a function of problematic drug usage? The link between impulsivity and SUDs has been most strongly established for cocaine and alcohol use disorders using both preclinical models and clinical data. Much less is known about the potential link between impulsivity and cannabis use disorder (CUD) or the directionality of this relationship. The initiation of cannabis use occurs most often during adolescence prior to the brain's maturation, which is recognized as a critical period of development. The long-term effects of chronic cannabis use on the brain and behavior have started to be explored. In this review we will summarize these observations, especially as they pertain to the relationship between impulsivity and CUD, from both a psychological and biological perspective. We will discuss impulsivity as a multi-dimensional construct and attempt to reconcile the results obtained across modalities. Finally, we will discuss possible avenues for future research with emerging longitudinal data.

The Development of Impulsivity and Sensation Seeking: Associations with Substance Use among At-Risk Adolescents

We investigated if the dual systems model could explain the increased rates of substance use among at-risk youth. This study sampled 365 adolescents, 289 of which had a family history of substance use disorder, assessed biannually between the ages 13-16 years old. Growth curve analyses revealed that higher levels of impulsivity were related to higher levels of sensation seeking and a slower rate of decline in impulsivity was related to a faster rate of increase in sensation seeking. Only family history status and sensation seeking were directly associated with substance use (marijuana, alcohol) at age 16, though family history status was also indirectly related to substance use through higher levels of impulsivity to higher levels of sensation seeking.

Impulsivity traits and neurocognitive mechanisms conferring vulnerability to substance use disorders

Impulsivity - the tendency to act without sufficient consideration of potential consequences in pursuit of short-term rewards - is a vulnerability marker for substance use disorders (SUD). Since impulsivity is a multifaceted construct, which encompasses trait-related characteristics and neurocognitive mechanisms, it is important to ascertain which of these aspects are significant contributors to SUD susceptibility. In this review, we discuss how different trait facets, cognitive processes and neuroimaging indices underpinning impulsivity contribute to the vulnerability to SUD. We reviewed studies that applied three different approaches that can shed light on the role of impulsivity as a precursor of substance use related problems (versus a consequence of drug effects): (1) longitudinal studies, (2) endophenotype studies including non-affected relatives of people with SUD, and (3) clinical reference groups-based comparisons, i.e., between substance use and behavioural addictive disorders. We found that, across different methodologies, the traits of non-planning impulsivity and affect-based impulsivity and the cognitive processes involved in reward-related valuation are consistent predictors of SUD vulnerability. These aspects are associated with the structure and function of the medial orbitofrontal-striatal system and hyperexcitability of dopamine receptors in this network. The field still needs more theory-driven, comprehensive studies that simultaneously assess the different aspects of impulsivity in relation to harmonised SUD-related outcomes. Furthermore, future studies should investigate the impact of impulsivity-related vulnerabilities on novel patterns of substance use such as new tobacco and cannabinoid products, and the moderating impact of changes in social norms and lifestyles on the link between impulsivity and SUD. This article is part of the special issue on 'Vulnerabilities to Substance Abuse'.

Distinct psychological profiles among college students with substance use: A cluster analytic approach

Substance use in youth is a central public health concern, related to deleterious consequences at psychological, social, and cognitive/cerebral levels. Previous research has identified impulsivity and consumption motives as key factors in the emergence of excessive substance use among college students. However, most studies have focused on a specific substance and have considered this population as a unitary group, ignoring the potential heterogeneity in psychological profiles. We used a cluster analytic approach to explore the heterogeneity in a large sample (N = 2741) of substance users (i.e., tobacco, alcohol, cannabis, ecstasy, cocaine, heroin) on impulsivity and consumption motives. We identified four clusters: The first two clusters, associated with good self-esteem, low anxiety, and moderate substance use, were respectively characterized by low impulsivity and consumption motives (Cluster 1) and by high social and enhancement motives without marked impulsivity (Cluster 2). The two other clusters were conversely related to low self-esteem and high anxiety, and characterized by high consumption motives (particularly conformity) together with elevated urgency (Cluster 3) and by globally increased impulsivity and consumption motives (Cluster 4). These two clusters were also associated with higher substance use. These results highlight the existence of distinct psychological profiles of substance users and underline the need to develop targeted prevention and intervention programs (e.g., focusing on the specific impulsivity facets and consumption motives presented by each subgroup). Based on these findings, we also suggest extending the exploration of distinct profiles of substance users by targeting other psychological variables (e.g., self-esteem).

Behavioral processes and risk for problem substance use in adolescents

This narrative review examines associations of delay discounting, response inhibition, sensation-seeking, and urgency with adolescent problem substance use. Each of these processes is linked to adult substance use disorders, is associated with conditions linked to increased risk for adolescent problem substance use, and predicts problem substance use. Notably, all processes are linked to early life adversity (ELA) exposure and most appear to help explain links between ELA exposure and problem substance use. These findings are consistent with a growing body of literature indicating ELA interferes with the development of neural circuits crucial to cognitive functioning and emotion regulation. Further, developmental trajectories of these processes generally align with maturational imbalance hypotheses of adolescent risk. Ongoing and pending large longitudinal studies may be essential for better understanding how ELA and other influences shapes these processes and the role of these processes in risk for problem substance use in adolescence and beyond. Finally it is possible that risk-related processes may be useful metrics in the context of implementing and evaluating strategies to prevent problem substance use in adolescence.

Impulsivity across substance use categories: Consideration of sex/gender

PURPOSE OF REVIEW

The goal was to review recent (1/2015-2/2020) evidence of impulsivity as a feature of substance use disorders or use of substances (alcohol, cannabis, nicotine, opioids, stimulants) in males compared to females in terms of: a) impulsivity in substance-using groups (or substance-using compared to control groups), and b) relationship between impulsivity and substance use behavior, clinical severity, or treatment outcomes.

RECENT FINDINGS

Of 361 papers identified by the searches, 69 met inclusion criteria, and 39 were highlighted for considering sex/gender in relation to impulsivity in substance-using populations. Taken together, findings supported higher impulsivity in males and females who use substances, relative to controls; and higher impulsivity was linked with more substance use/severity in both sex/genders. There were mixed findings regarding male versus female differences in impulsivity among individuals who use substances, or in the magnitude of the relationship between impulsivity and substance use severity.

SUMMARY

The current body of evidence does not point to a consistent sex/gender difference in the role of impulsivity within and across substance use disorders. Impulsivity is a clinically-relevant construct for male and female individuals who use substances, across a range of substances.

Juvenile exposure to methylphenidate and guanfacine in rats: effects on early delay discounting and later cocaine-taking behavior

RATIONALE

Both methylphenidate (MPH), a catecholamine reuptake blocker, and guanfacine, an alpha2A agonist, are used to treat attention-deficit hyperactivity disorder (ADHD). Childhood impulsivity, including delay discounting, is associated with increased substance use during adolescence. These effects can be mitigated by juvenile exposure to MPH, but less is known about the long-term effects of developmental exposure to guanfacine in males and females.

OBJECTIVE

This study aims to determine sex differences and dose-dependent effects of juvenile exposure to MPH or guanfacine on delay-discounting and later cocaine self-administration.

METHODS

The dose-dependent effects of vehicle, MPH (0.5, 1, and 2 mg/kg p.o.) or guanfacine (0.003, 0.03, and 0.3 mg/kg, i.p.) on discounting were determined in male and female Sprague-Dawley rats beginning at postnatal day (P)20. At P90, the amount, motivation, and sensitivity to cocaine following early drug exposure were determined with self-administration.

RESULTS

Guanfacine, but not MPH, significantly reduced weight by 22.9 ± 4.6% in females. MPH dose dependently decreased delay discounting in both juvenile males and females, while guanfacine was only effective in males. Discounting was associated with cocaine self-administration in vehicle males (R² = -0.4, P < 0.05) and self-administration was reduced by guanfacine treatment (0.3 mg/kg). Guanfacine significantly decreased cocaine sensitivity in both sexes.

CONCLUSIONS

These data suggest that MPH is effective in reducing delay discounting in both sexes. Due to both weight loss and ineffectiveness on discounting in females, guanfacine should be used only in males to reduce delay discounting and later cocaine use.