Biological underpinnings of an internalizing pathway to alcohol, cigarette, and marijuana use

The role of parenting in developmental trajectories of risk for adolescent substance use: a bioecological systems cascade model

Parenting is a key influence and prevention target for adolescent substance use, and changes dramatically in form and function during adolescence. This theoretical synthesis reviews evidence of associations of substance use-specific parenting behaviors, dimensions, and styles with adolescent substance use, and integrates key developmental and family theories (e.g., bioecological, dynamical systems, family systems, developmental cascades) and methodological-conceptual advances to illustrate the complex role that parenting plays for the development of adolescent substance use in combination with child and contextual influences. The resulting bioecological systems cascade model centers the dynamic co-development of parenting and child influences in developmental cascades that lead to more or less risk for adolescent substance use. These trajectories are initiated by intergenerational influences, including genetics, parents' familial environments, and child-parent attachment. Culture and context influences are a holistic backdrop shaping parent-adolescent trajectories. Parenting is influences are conceptualized as a complex process by which specific parenting behaviors are informed by and accumulate into parenting dimensions which together comprise general parenting styles and are informed by the broader family context. The co-development of parenting and child biobehavioral risk is shaped by both parents and children, including by the genetics and environments they do and do not share. This co-development is dynamic, and developmental transitions of individuals and the family lead to periods of increased lability or variability that can change the longer-term trajectories of children's risk for substance use. Methodological avenues for future studies to operationalize the model are discussed.

The association of amygdala-insula functional connectivity and adolescent e-cigarette use via sleep problems and depressive symptoms

BACKGROUND

Adolescent electronic cigarette (e-cigarette) use remains high. Elucidating contributing factors may enhance prevention strategies. Neurobiologically, amygdala-insula resting-state functional connectivity (rsFC) has been linked with aspects of sleep, affect, and substance use (SU). As such, we hypothesized that amygdala's rsFC with the insula would be associated with e-cigarette use via sleep problems and/or depression levels.

METHODS

An adolescent sample (N = 146) completed a rs-fMRI scan at time 1 and self-reports at time 2 (∼15 months later). Given consistent associations between mental health outcomes and the rsFC of the laterobasal amygdala (lbAMY) with the anterior insula, we utilized a seed region (lbAMY) to region of interest (ROI) analysis approach to characterize brain-behavior relationships. Two serial mediation models tested the interrelations between amygdala's rsFC with distinct anterior insula subregions (i.e., ventral insula [vI], dorsal insula [dI]), sleep problems, depression levels, and days of e-cigarette use.

RESULTS

An indirect effect was observed when considering the lbAMY's rsFC with the vI. Greater rsFC predicted more sleep problems, more sleep problems were linked with greater depressive symptoms, and greater depressive symptoms were associated with more e-cigarette use (indirect effect = 0.08, CI [0.01,0.21]). Indicative of a neurobiological dissociation, a similar indirect effect linking these variables was not observed when considering the lbAMY's rsFC with the dI (indirect effect = 0.03, CI [-0.001,0.10]).

CONCLUSIONS

These outcomes highlight functional interactions between the amygdala and insula as a neurobiological contributor to sleep problems, depressive symptoms, and ultimately SU thereby suggesting potential intervention points to reduce teen e-cigarette use.

A Genome-Wide Association Study Reveals a BDNF-Centered Molecular Network Associated with Alcohol Dependence and Related Clinical Measures

At least 50% of factors predisposing to alcohol dependence (AD) are genetic and women affected with this disorder present with more psychiatric comorbidities, probably indicating different genetic factors involved. We aimed to run a genome-wide association study (GWAS) followed by a bioinformatic functional annotation of associated genomic regions in patients with AD and eight related clinical measures. A genome-wide significant association of rs220677 with AD (p-value = 1.33 × 10^-8 calculated with the Yates-corrected χ² test under the assumption of dominant inheritance) was discovered in female patients. Associations of AD and related clinical measures with seven other single nucleotide polymorphisms listed in previous GWASs of psychiatric and addiction traits were differently replicated in male and female patients. The bioinformatic analysis showed that regulatory elements in the eight associated linkage disequilibrium blocks define the expression of 80 protein-coding genes. Nearly 68% of these and of 120 previously published coding genes associated with alcohol phenotypes directly interact in a single network, where BDNF is the most significant hub gene. This study indicates that several genes behind the pathogenesis of AD are different in male and female patients, but implicated molecular mechanisms are functionally connected. The study also reveals a central role of BDNF in the pathogenesis of AD.

Electronic Cigarette Use Intentions Mediate the Association between Low Self-Control and Future Use by Internalizing Symptoms

Background: Adolescent electronic (e-)cigarette use intentions are related to initiation. Low self-control is also a risk factor for early stages of substance use. Yet, the impact of low self-control on use through intentions may vary across individuals; depression and anxiety may affect this association. Methods: A sample of 200 adolescents who completed waves 1 and 2 of an ongoing longitudinal study were assessed. We hypothesized that high internalizing symptoms would moderate the indirect effect of low self-control on actual e-cigarette use through e-cigarette use intentions. Results: The mediation pathway was significant at high levels of internalizing symptoms, but not at low or moderate levels. Conclusion: Specifically, those with low self-control and high internalizing symptomatology endorsed the highest e-cigarette use intentions and were more likely to subsequently use e-cigarettes. Youth low in self-control and high in depression and anxiety might be at increased risk to initiate e-cigarette use compared to youth high in self-control and high in internalizing symptomatology.

Is Empathy Associated with Gambling and Its Addiction? A Scoping Review of Empirical Studies

Considering the low levels of empathy associated with substance-related addictions and the similarities between gambling disorder (GD) and substance-related addiction, understanding the relationship between empathy and GD may clarify the mechanism of addiction development. This scoping review aimed to evaluate the empirical evidence for the potential protective role of emotional and cognitive empathy against GD development via internalizing and/or externalizing pathways. We followed the preferred reporting items for systematic review and meta-analyses extension for scoping reviews and 11 articles met the inclusion criteria. Although most of the reviewed studies used correlational designs and non-gambling-specific samples, this review highlights (1) significant relationships between both types of empathy and the neural activity of gambling behaviors, and (2) reduced cognitive empathy (i.e., fantasy and perspective taking) and increased emotional empathy (i.e., personal distress) among problem gamblers than their gambling counterparts. Despite the lack of studies directly testing the protective role of empathy against GD, the existing studies (n = 8) nevertheless shed light on the potential protective effects of both types of empathy on GD development. This review identified research gaps, which can be addressed in future studies by discovering the underlying mechanisms (e.g., internalizing and externalizing pathways) of these relationships. Experimental or longitudinal studies in gamblers investigating how different types of empathy are associated with GD via these pathways are called for as their findings have implications for prevention and intervention designs for GD and other addictive disorders.

Chronic pain and delinquency partially explain the effect of the DRD4 gene polymorphism on adult substance use

Background: The dopamine receptor D4 [DRD4] has been reported to be associated with substance use. Yet, the roles that health conditions and behaviors may play in such association are understudied.Objective: This longitudinal study investigated the potential mediation effects of chronic pain and delinquency in adolescence on the association between the DRD4 2-repeat allele and substance use in adulthood. Sex, witnessing violence, and experiencing violence were also examined as potential moderators for the mediation pathways.Methods: We used the restricted and candidate gene data from the National Longitudinal Study of Adolescent to Adult Health (Waves I-IV) to conduct secondary analysis (N = 8,671; 47% male). A two-step approach was adopted to examine the mediation effects regarding four substance use outcomes in adulthood: number of lifetime alcohol use disorder symptoms, lifetime regular smoker status, past-month smoking, and lifetime "pain killer" misuse. The moderation effects were investigated using stratification and permutation.Results: The DRD4 2-repeat allele was associated with all adulthood substance use outcomes through adolescent chronic pain and delinquency (AORs/IRR range 1.08-3.78; all ps<0.01). The association between delinquency and smoking was higher among females. The association between delinquency and substance use was lower among the participants who witnessed violence in adolescence.Conclusions: This study identified modifiable mediators underlying the association between the DRD4 2-repeat allele and substance use behaviors, concluding that chronic pain and delinquency partially explain the effect of the DRD4 gene polymorphism on adult substance use.

Beyond internalizing and externalizing symptoms: The association between body disconnection and the symptoms of Internet gaming disorder

As the vast majority of online videogames imply the immersion into an alternative reality where a virtual body is also involved, the current cross-sectional study aims to investigate the contribution of low body awareness (i.e. low attention to sensory cues indicating bodily state) and body dissociation (i.e. low emotional connection with one's own body) in predicting Internet gaming disorder (IGD) symptoms, after controlling for internalizing (i.e., depression, anxiety, and stress) and externalizing symptoms (i.e., aggression). A total of 370 online-game players (73% men; mean age 29.63 ± 7.64 years) recruited in online player communities took part in the study and were given a survey that included gaming characteristics, the Depression, Anxiety and Stress Scale -21, the Aggression Questionnaire, the Body Disconnection Scale, and the Internet Gaming Disorder Scale- Short Form. A hierarchical regression analysis showed that low body awareness and high body dissociation predicted IGD scores after controlling for all the other factors. Moreover, we found an interaction effect between physical aggression and body dissociation in predicting IGD scores. On the one hand, these results provide support to previous studies that stressed the potential association between dissociative detachment (in terms of bodily disconnections) and problematic videogaming; on the other hand, the current study provides first evidence of the opportunity to focus on the integration of bodily experiences in clinical practice with people suffering from problematic gaming, as this factor might be incisively related to their aggressive and internalizing symptoms.

The externalizing and internalizing pathways to marijuana use initiation: Examining the synergistic effects of impulsiveness and sensation seeking

Adolescent marijuana use has become increasingly more problematic compared with the past; thus, understanding developmental processes that increase the liability of marijuana use is essential. Two developmental pathways to adolescent substance use have been proposed: an externalizing pathway that emphasizes the expression of aggressive and delinquent behavior, and an internalizing pathway that emphasizes the role of depressive symptoms and negative affect. In this study, we aimed to examine the synergistic role of impulsiveness and sensation seeking in the two risk pathways to determine whether both high and low levels of the traits are risk factors for marijuana use. Our study included 343 adolescents (52% were girls, 78% identified as Hispanic) that oversampled high-risk youth (78% had a family history of substance use disorder), assessed biannually between the ages of 13-16 years old. Moderated mediation analyses revealed that high levels of sensation seeking indirectly predicted marijuana use through higher mean levels of externalizing behavior. The positive relationship between sensation seeking and externalizing behavior was only significant at high levels of impulsiveness. Conversely, low levels of sensation seeking indirectly predicted marijuana use through higher mean levels of internalizing behavior. The negative relationship between sensation seeking and internalizing behavior was only significant at low levels of impulsiveness. Collectively, these results demonstrate that high and low levels of both impulsiveness and sensation seeking confer increased risk of marijuana use, albeit through different mechanisms. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Developmental Cascades from Polygenic and Prenatal Substance Use to Adolescent Substance Use: Leveraging Severity and Directionality of Externalizing and Internalizing Problems to Understand Pubertal and Harsh Discipline-Related Risk

The current study leveraged the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort (n = 4504 White boys, n = 4287 White girls assessed from the prenatal period through 18.5 years of age) to test a developmental cascade from genetic and prenatal substance use through pubertal timing and parenting to the severity of (regardless of type) and directionality (i.e., differentiation) of externalizing and internalizing problems to adolescent substance use. Limited associations of early pubertal timing with substance use outcomes were only observable via symptom directionality, differently for girls and boys. For boys, more severe exposure to prenatal substance use influenced adolescent substance use progression via differentiation towards relatively more pure externalizing problems, but in girls the associations were largely direct. Severity and especially directionality (i.e., differentiation towards relatively more pure externalizing problems) were key intermediaries in developmental cascades from parental harsh discipline with substance use progressions for girls and boys.

Estimating causal and time-varying effects of maternal smoking on youth smoking

INTRODUCTION

Maternal smoking is a well-known risk factor for youth smoking, yet whether this relationship is causal remains unresolved. This study utilizes propensity score methods for causal inference to robustly account for shared risk factors between maternal and offspring smoking.

METHODS

An 8-year longitudinal cohort of 900 adolescents in the Chicago area were followed starting from approximately age 15.6. The effects of maternal lifetime smoking (MLS) and prenatal tobacco exposure (PTE) (among participants reporting MLS) on offspring's past 30-day smoking, daily smoking status and smoking frequency were examined using logistic regression and Poisson regression after nearest-neighbor propensity matching. Age dependency of this relationship was then examined across the age range of 15-25 using time-varying effect modeling.

RESULTS

Propensity matching yielded 438 and 132 pairs for MLS and PTE study samples, respectively. MLS demonstrated significant associations with past 30-day smoking (RR 1.09; 95% CI 1.04-1.14), daily smoking (RR 1.08; 95% CI 1.05-1.12), and smoking frequency of offspring (RR 1.32; 95% CI 1.15-1.52), with stable effects across age. Among participants reporting MLS, having PTE showed significant additional effects on daily smoking (RR 1.09; 95% CI 1.02-1.17) and age-dependency that showed significance during young adulthood but not adolescence.

CONCLUSION

The relationship between maternal and offspring smoking was not fully accounted for by shared risk factors, suggesting possible causation with PTE having a delayed effect across age. Targeted prevention efforts should be made on maternal smoking-exposed adolescents to mitigate their risks of developing heavy smoking habits in adulthood.

Unique, long-term effects of nicotine on adolescent brain

Adolescence is a time of major plasticity of brain systems that regulate motivated behavior and cognition, and is also the age of peak onset of nicotine use. Although there has been a decline in teen use of cigarettes in recent years, there has been a huge increase in nicotine vaping. It is therefore critically important to understand the impact of nicotine on this critical phase of brain development. Animal studies have shown that nicotine has unique effects on adolescent brain. The goal of this review is therefore to systematically evaluate age- and sex-differences in the effects of nicotine on brain and behavior. Both acute and chronic effects of nicotine on brain biochemistry and behavior, particularly drug reward, aversion, cognition and emotion, are evaluated. Gaps in our current knowledge that need to be addressed are also highlighted. This review compares and integrates human and animals findings. Although there can be no experimental studies in humans to confirm similar behavioral effects of teen nicotine exposure, an emerging observational literature suggests similarities across species. Given the substantial evidence for long-term negative impact of adolescent nicotine exposure on brain and behavior, further longitudinal assessment of health outcomes in teen and young adult e-cigarette users is warranted.

Conduct problems and depressive symptoms in association with problem gambling and gaming: A systematic review

BACKGROUND AND AIMS

Behavioral addictions such as gambling and gaming disorder are significant public health issues that are of increasing importance to policy makers and health care providers. Problem gambling and gaming behaviors have been identified as being associated with externalizing and internalizing problems, with theoretical models suggesting that both conduct problems and depressive symptoms may be significant risk factors in the development of problem gambling and gaming. As such, the purpose of this systematic review is to provide an overview of research identifying the relationship between conduct problems, depressive symptoms and problem gambling and gaming among adolescents and young adults.

METHODS

Systematic literature searches in accordance with PRISMA guidelines found 71 eligible studies that met the inclusion criteria, 47 for problem gambling, 23 for problem gaming and one for both problem behaviors.

RESULTS

Based on cross-sectional evidence, both problem gambling and gaming are consistently concurrently associated with conduct problems and depressive symptoms. Longitudinal evidence appears to be clearer for conduct problems as a risk factor for problem gambling, and depressive symptoms as a risk factor for problem gaming. However, both risk factors appear to increase the risk for these problem behaviors.

DISCUSSION AND CONCLUSIONS

Results from the literature review suggest that problem gambling and gaming are associated with the presence of conduct problems and depressive symptoms, with the potential of sharing common etiological factors. Additional research is necessary to confirm these longitudinal relationships with an emphasis on investigating the interaction of both early conduct problems and depressive symptoms.

Early Signs of Emotional Recognition Deficits in Adolescent High-Binge Drinkers

Background: Emotional dysregulation, measured with face recognition tasks, is prevalent in alcohol use disorders (AUD), constituting a risk factor for alcohol use and relapse. It is not clear however whether emotional dysregulation is a by-product of alcohol consumption, or if it can act as a predisposing factor for AUD. Objective: Our aim was to examine early signs of emotional dysregulation in adolescent drinkers. Method: Twenty-four high-school students and 24 university students completed two tasks. On the first one, participants had to gradually increment the emotional content of different faces until they could perceive an emotional expression (emotion perception threshold task). We also examined the propensity to perceive fearful expressions in an emotion identification task. Participants were semantically primed with emotion words (i.e., "fear"), and they then had to indicate whether a neutral-fearful facial composite matched the prime. Results: Using repeated-measures ANOVAS, in the emotion perception threshold task, "happy" faces were the easiest to detect and "sad" ones the hardest. For high school students there was a differential response pattern depending on binge scores, such that High-binge drinkers found it easier to detect a sad face but harder to detect a happy one compared to Low-binge drinkers. In the facial emotion identification task, Low-binge drinkers observed more fearful expressions compared to High-binge drinkers. Conclusions: Differences in emotional processing in young adolescents depending on drinking habits point towards the relevance of emotional dysregulation as an early sign of AUD. These findings could help develop novel diagnostic and treatment tools for young populations.

Developmental Pathways from Genetic, Prenatal, Parenting and Emotional/Behavioral Risk to Cortisol Reactivity and Adolescent Substance Use: A TRAILS Study

Cortisol reactivity is a frequently studied biomarker of substance use, though infrequently examined in adolescence. However, past research provides evidence that multiple developmental influences, including genetics and both prenatal and postnatal environmental influences, contribute both to cortisol reactivity and adolescent substance use. The aim of this study was to assess the impact of these earlier developmental influences on cortisol reactivity to a social stress challenge and adolescent substance use (smoking, alcohol, and marijuana use frequency assessed at age 16 years), using data from the TRacking Adolescents' Individual Lives Survey (TRAILS; N= 2230 adolescents, 51% female). Developmental pathways included polygenic risk, prenatal stress, warm parenting (age 11), and internalizing and externalizing problems (intercepts and change from 11-16 years). Cortisol reactivity was associated with smoking but not alcohol or marijuana use. Externalizing problems were the stronger predictor of adolescent substance use, but internalizing problems also had an important role. Prenatal stress and middle childhood parenting operated via middle childhood externalizing problems, and parenting also operated via trajectories of growth of externalizing problems in predicting adolescent substance use outcomes. Further, there were protective effects of internalizing problems for alcohol and marijuana use in the context of a more comprehensive model. These developmental influences did not attenuate the association of cortisol reactivity and smoking. These findings suggest a need to understand the broader developmental context regarding the impact of internalizing pathways to substance use, and that it is unlikely that cortisol reactivity and smoking are associated solely because of common developmental influences.

The Impact of Genes on Adolescent Substance Use: A Developmental Perspective

Purpose

This review discusses the importance of understanding the impact of genetic factors on adolescent substance use within a developmental framework. Methods for identifying genetic factors, relevant endophenotypes and intermediate phenotypes, and gene-environment interplay effects will be reviewed.

Findings

Prior work supports the role of polygenic variation on adolescent substance use. Mechanisms through which genes impact adolescent phenotypes consist of differences in neural structure and function, early temperamental differences, and problem behavior. Gene-environment interactions are characterized by increased vulnerability to both maladaptive and adaptive contexts.

Summary

Developmental considerations in genetic investigations highlight the critical role that polygenic variation has on adolescent substance use. Yet, determining what to do with this information, especially in terms of personalized medicine, poses ethical and logistic challenges.