Age of alcohol and cannabis use onset mediates the association of transmissible risk in childhood and development of alcohol and cannabis disorders: evidence for common liability

The intermediary role of adolescent temperamental and behavioral traits on the prospective associations between polygenic risk and cannabis use among young adults of European Ancestry

BACKGROUND AND AIMS

Cannabis use (CU) is an etiologically complex behavior with several social, temperamental, neurocognitive, and behavioral precursors. Biometrical and molecular studies suggest an interplay of environmental and pleiotropic influences. However, it remains unclear whether identified genetic effects related to behavioral and temperamental characteristics have developmentally direct or indirect mechanisms on CU behavior. The Transmissible Liability Index (TLI) is a measure of continuous liability based on developmental precursors of substance use disorders. This study aimed to examine if the TLI plays a role in understanding genetic risk for CU behaviors.

DESIGN

Genome-wide association studies (n > 10 000; European Ancestry [EA]) of CU, risk tolerance, neuroticism, anxiety, and depression were used to construct polygenic scores (PGSs). Analyses assessed whether PGSs indirectly impacted risk for repeated use via TLI.

SETTING

United States of America.

PARTICIPANTS

From Add Health study, 4077 individuals of EA age 11 to 21 during baseline interview collection.

MEASUREMENTS

Outcomes were initiation and repeated cannabis use (>5× in lifetime). The TLI was parameterized using a latent factor from 21 questions assessing for precursors of disordered use.

FINDINGS

The marker-based heritability of TLI, initiation, and repeated use were significant, but modest (14%, P = 0.033; 15%, P = 0.025; and 17%, P = 0.008, respectively). TLI and repeated use were genetically correlated (r_g  = 0.76, P = 0.033). The PGS for CU was associated with increased risk for repeated use and PGS for risk tolerance and depression were associated with TLI. Mediation analyses indicated significant, but very weak, indirect effects of PGS for risk tolerance and depression on repeated CU via the TLI.

CONCLUSIONS

Adolescent behavioral and temperamental characteristics (i.e. the Transmissible Liability Index) appear to be early indicators of repeated cannabis use in adulthood. Although polygenic scores for cannabis use directly increased risk for repeated cannabis use, weak evidence was found for the role of polygenic scores of other internalizing/externalizing traits acting through adolescent derived Transmissible Liability Index on cannabis use behavior.

Alcohol and Brain Development in Adolescents and Young Adults: A Systematic Review of the Literature and Advisory Report of the Health Council of the Netherlands

Young people, whose brains are still developing, might entail a greater vulnerability to the effects of alcohol consumption on brain function and development. A committee of experts of the Health Council of the Netherlands evaluated the state of scientific knowledge regarding the question whether alcohol negatively influences brain development in young people. A systematic literature search for prospective studies was performed in PubMed and PsychINFO, for longitudinal studies of adolescents or young adults ranging between 12 and 24 y of age at baseline, investigating the relation between alcohol use and outcome measures of brain structure and activity, cognitive functioning, educational achievement, or alcohol use disorder (AUD), with measures at baseline and follow-up of the outcome of interest. Data were extracted from original articles and study quality was assessed using the Newcastle-Ottawa Scale. A total of 77 studies were included, 31 of which were of sufficient quality in relation to the study objectives. There were indications that the gray matter of the brain develops abnormally in young people who drink alcohol. In addition, the more often young people drink or the younger they start, the higher the risk of developing AUD later in life. The evidence on white matter volume or quality, brain activity, cognitive function, and educational achievement is still limited or unclear. The committee found indications that alcohol consumption can have a negative effect on brain development in adolescents and young adults and entails a risk of later AUD. The committee therefore considers it a wise choice for adolescents and young adults not to drink alcohol.

Adolescent Behavioral Characteristics Mediate Familial Effects on Alcohol Use and Problems in College-Bound Students

BACKGROUND

Studies suggest a broad spectrum of behaviors associated with drinking. Consequently, it is unclear whether patterns of familial risk for psychopathology are directly or indirectly related to patterns of alcohol use and problems in late adolescence or mediated by behavioral characteristics, such as temperament, mood.

OBJECTIVES

We examined direct and indirect effects of perceived family history of psychopathology on pre-collegiate alcohol use and problems via the Transmissible Liability Index (TLI).

METHODS

Participants (N = 302; 29.6% male) provided self-report data on age of onset of drinking, past 90-day frequency of alcohol use and problems (AUP), family history of internalizing and alcohol and illicit substance use, and TLI.

RESULTS

Approximately 21% of participants reported having at least one relative with a history of regular and/or problematic alcohol use, compared to 12% for illicit substance use, and -55% for internalizing problems. Higher TLI scores were associated with increased family history of substance use, alcohol use, and internalizing problems, as well as earlier age of onset of drinking. Family history of internalizing problems was the most robust indicator of AUP (β = 0.20 [95% CI = 0.04-0.36], P = .01). Path analyses suggested that the individual-level behaviors that comprise TLI mediate the effects of family history on age of initiation and regular alcohol consumption.

CONCLUSIONS

Family history of internalizing, drinking, and illicit substance use reflect generalized risk for a broad set of behaviors associated with risk for alcohol initiation and use during the transition from high school to college.

School-based interventions for preventing substance use in indigenous children ages 7-13: a scoping review protocol

INTRODUCTION

Throughout the world, indigenous peoples share traumatic colonial experiences that have caused gross inequalities for them and continue to impact every aspect of their lives. The effect of intergenerational trauma and other health disparities have been remarkable for Indigenous children and adolescents, who are at a greater risk of adverse mental health and addiction outcomes compared with non-indigenous people of the same age. Most indigenous children are exposed to addictive substances at an early age, which often leads to early initiation of substance use and is associated with subsequent physical and mental health issues, poor social and relational functioning, and occupational and legal problems. The aim of this paper is to report the protocol for the scoping review of school-based interventions for substance use prevention in Indigenous children ages 7-13 living in Canada, the USA, Australia and New Zealand. This scoping review seeks to answer the following questions: (1) What is known about indigenous school-based interventions for preventing substance use and (2) What are the characteristics and outcomes of school-based interventions for preventing substance use?

METHODS AND ANALYSIS

This scoping review will use steps described by Arksey and O'Malley and Levac: (1) identifying the research question(s); (2) identifying relevant studies; (3) selecting the studies; (4) charting the data; (5) collating, summarising and reporting the results and (6) consulting with experts. Our findings will be reported according to the guidelines set by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews.

ETHICS AND DISSEMINATION

Ethics review approval is not required for this project. Findings from this study will be presented to lay public, at scientific conferences and published in a peer-reviewed journal.

Intergenerational marijuana use: A life course examination of the relationship between parental trajectories of marijuana use and the onset of marijuana use by offspring

Prior research documents intergenerational (IG) continuity in marijuana use, with most work adopting a life course perspective. Incorporating a methodology that allows for the measurement of "patterns of behavior" instead of singular aspects of parent marijuana use (e.g., age of onset or frequency at any one age or ages), we investigated the simultaneous effects of parental age of onset, frequency, and duration of marijuana use across 3 periods of the life course (i.e., adolescence, emerging adulthood, and adulthood) on the timing of first marijuana use among offspring. Using prospective data from 2 companion studies, the Rochester Youth Development Study and the Rochester Intergenerational Study, we used group-based trajectory models to estimate trajectories (or patterns) of parental marijuana use spanning ages 14 to 31 among a birth cohort of 462 parents. We then examined the relationship between parental trajectories of marijuana use and the timing of the onset of marijuana use through age 25 among firstborn offspring. Both late-onset persistent use by parents and increasing chronic use spanning adolescence to adulthood by parents were associated with an increased likelihood of onset of marijuana use among offspring. The results underscore the importance of patterns of marijuana use for IG continuity in contrast to singular measures (e.g., age of onset among parents), which can obfuscate important IG patterns of continuity. Prevention and intervention programs should consider the entire history of parent use to better identify children most at risk for the onset of marijuana use in adolescence and emerging adulthood. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Influence of Early Onset of Alcohol Use on the Development of Adolescent Alcohol Problems: a Longitudinal Binational Study

This study examined cross-national similarities in a developmental model linking early age of alcohol use onset to frequent drinking and heavy drinking and alcohol problems 1 and 2 years later in a binational sample of 13-year-old students from two states: Washington State, USA and Victoria, Australia (N = 1833). A range of individual, family, school, and peer influences was included in analyses to investigate their unique and shared contribution to development of early and more serious forms of alcohol use and harms from misuse. Data were collected annually over a 3-year period from ages 13 to 15. Analyses were conducted using multiple-group structural equation modeling. For both states, early use of alcohol predicted frequent drinking, which predicted alcohol problems. Family protective influences had neither direct effects on heavy drinking nor effects on alcohol harm in either state, whereas school protection directly reduced the risk of heavy drinking in both states. Exposure to antisocial peers and siblings predicted a higher likelihood of heavy drinking and alcohol harm for students in both Washington and Victoria. Implications for the prevention of adolescent alcohol problems are discussed.

Longitudinal Studies on the Etiology of Cannabis Use Disorder: A Review

PURPOSE OF REVIEW

This review summarizes the literature to date that has capitalized on the longitudinal research study framework in order to elucidate the etiology of cannabis use disorders (CUDs).

RECENT FINDINGS

The studies are mixed with respect to reliable predictors of CUD development. Of the studies outlined, the most consistently indicated risk factors for CUD development include: male sex, past cannabis and other substance use (especially tobacco), and the presence of pre/comorbid psychopathology (especially mood disorders). Social motives and peer involvement may also play a role in this transition. Many of these CUD risk factors appear to be distinct from other factors linked with overall cannabis use.

SUMMARY

CUD development is likely the product of interactions between biological, psychological, social, and environmental factors. However, many more well-planned and developmentally sensitive prospective studies are needed to identify specific and reliable risk factors for CUD development.

Global white matter microstructural abnormalities associated with addiction liability score in drug naïve youth

Abnormalities in brain white matter (WM) structure have been reported in youths having a family history of substance use disorders (SUDs). It was hypothesized that these abnormalities constitute features of the liability for SUDs transmitted across generations. The association between severity of intergenerational risk for SUD, measured by the Transmissible Liability Index (TLI), and white matter microstructure was examined. Diffusion tensor imaging (DTI) measured WM microstructure in forty-four drug-naïve 10-14 year-olds (N = 19 with parental SUD). Metrics of WM microstructure (i.e., fractional anisotropy, radial diffusivity, mean diffusivity and axial diffusivity) were quantified across the whole brain and in four tracts of interest: anterior corona radiata, superior and inferior longitudinal fasciculi and superior fronto-occipital fasciculi. The TLI was completed by the youths, their parents and, when available, their teachers. The relationship between WM structure and TLI score across the entire group was evaluated using linear multiple regression and between group comparisons were also examined. Fractional anisotropy and radial diffusivity in multiple tracts across the brain were significantly associated with TLI scores. Confirming and extending prior research, the findings indicate that global atypicality in WM tracts was linearly related to liability for eventual SUD development in drug naïve youths.

Neurodevelopmental Precursors and Consequences of Substance Use during Adolescence: Promises and Pitfalls of Longitudinal Neuroimaging Strategies

Neurocognitive and emotional regulatory deficits in substance users are often attributed to misuse; however most studies do not include a substance-naïve baseline to justify that conclusion. The etiological literature suggests that pre-existing deficits may contribute to the onset and escalation of use that are then exacerbated by subsequent use. To address this, there is burgeoning interest in conducting prospective, longitudinal neuroimaging studies to isolate neurodevelopmental precursors and consequences of adolescent substance misuse, as reflected in recent initiatives such as the NIH-led Adolescent Brain Cognitive Development (ABCD) study and the National Consortium on Alcohol and Neurodevelopment (NCANDA). To distinguish neurodevelopmental precursors from the consequences of adolescent substance use specifically, prospective, longitudinal neuroimaging studies with substance-naïve pre-adolescents are needed. The exemplar described in this article—i.e., the ongoing Adolescent Development Study (ADS)—used a targeted recruitment strategy to bolster the numbers of pre-adolescent individuals who were at increased risk of substance use (i.e., “high-risk”) in a sample that was relatively small for longitudinal studies of similar phenomena, but historically large for neuroimaging (i.e., N = 135; 11–13 years of age). At baseline participants underwent MRI testing and a large complement of cognitive and behavioral assessments along with genetics, stress physiology and interviews. The study methods include repeating these measures at three time points (i.e., baseline/Wave 1, Wave 2 and Wave 3), 18 months apart. In this article, rather than outlining specific study outcomes, we describe the breadth of the numerous complexities and challenges involved in conducting this type of prospective, longitudinal neuroimaging study and “lessons learned” for subsequent efforts are discussed. While these types of large longitudinal neuroimaging studies present a number of logistical and scientific challenges, the wealth of information obtained about the precursors and consequences of adolescent substance use provides unique insights into the neurobiological bases for adolescent substance use that will lay the groundwork for targeted interventions.

Temperament disturbances measured in infancy progress to substance use disorder 20 years later

OBJECTIVE

This prospective study determined whether temperament before two years of age predicts transmissible risk for substance use disorder (SUD) up to a decade later and SUD outcome in adulthood.

METHOD

Boys between 10 and 12 years of age (N = 482) were tracked to age 22. The previously validated transmissible liability index (TLI) was administered at baseline, and temperament prior to two years of age was retrospectively rated. The Structured Clinical Interview for DSM-III-R (SCID) was administered to document presence/absence of SUD for parents at baseline and sons at age 22.

RESULTS

Path analysis revealed that number of parents with SUD predicted severity of temperament disturbance in their sons which in turn predicted TLI score at age 10-12, presaging SUD. Temperament before age two did not predict SUD at age 22. The association between number of SUD parents and transmissible risk was mediated by severity of temperament disturbance.

CONCLUSION

Temperament disturbance in early childhood, reflecting quality of behavioral and emotion regulation, comprise psychological antecedents of transmissible risk for SUD.

A new approach to researching the etiology of cannabis use disorder: integrating transmissible and nontransmissible risk within a developmental framework

Rapidly occurring changes in law enforcement and licensing of retail outlets to sell marijuana raises the prospect that the population of consumers will expand and accordingly the prevalence of cannabis use disorder (CUD) will increase. This report presents a novel approach to researching CUD etiology joining multivariate and ontogenetic perspectives. CUD is conceptualized as a developmental outcome consisting of transmissible (intergenerational) and nontransmissible components. Partitioning the liability for CUD into these 2 dimensions enables implementing interventions targeted at the particular source and severity of risk. In addition, results showing that infant temperament disturbances predict transmissible risk leading to CUD 2 decades later underscore the importance of implementing early prevention.

Longitudinal Modeling of the Association Between Transmissible Risk, Affect During Drug Use and Development of Substance Use Disorder

OBJECTIVE

This longitudinal investigation examined the hypothesis that subjective experience during consumption of preferred drugs mediates the association of transmissible risk for substance use disorder (SUD) measured in childhood and adolescence, and SUD diagnosis in adulthood. Transmissible risk denotes the psychological characteristics having intergenerational continuity between parents and their biological children.

METHODS

The transmissible liability index (TLI) was administered to four hundred eighty-three 10 to 12-year-old boys (baseline). Follow-up evaluations were conducted when the boys attained 12-14, 16, 19, and 22 years of age, using age-specific versions of the TLI. Frequency of consumption of the participants' three most preferred drugs, affect on an ordinary day, affect while under influence of the preferred substances, and presence/absence of current SUD were assessed at 22 years of age.

RESULTS

Consumption frequency of preferred drugs among boys mediates the association of transmissible risk during childhood, and adolescence and SUD diagnosis in adulthood. Severity of negative affect on a drug-free day predicts frequency of consumption of preferred drugs, which, in turn, predicts severity of negative affect during the drug use event. Neither affect on a drug-free day nor affect during the drug use event mediates the association of transmissible risk and SUD.

CONCLUSIONS

Affect on drug-free days, and while under influence of preferred substances, covary with consumption frequency; however, affect is not related to transmissible SUD risk or SUD outcome.

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.

Comorbidity and temporal relations of alcohol and cannabis use disorders from youth through adulthood

BACKGROUND

Alcohol and cannabis are among the most widely used and abused drugs in industrialized societies. Investigations of patterns in comorbidity and temporal sequencing between alcohol use disorders (AUDs) and cannabis use disorders (CUDs) from childhood to adulthood are important for understanding the etiologies of these disorders.

METHODS

The sample comprised 816 individuals (59% male, 89% white). Dichotomous measures indicated whether or not a participant was in an AUD or CUD episode during three developmental periods-youth (childhood through adolescence), early adulthood, and adulthood. Structural equation modeling was used to determine relations between AUDs and CUDs across the three developmental periods, and to test for gender differences.

RESULTS

Concurrent associations between AUD and CUD were significant. Both AUD and CUD in previous developmental periods significantly predicted the same substance disorders in subsequent periods. Cross-lagged paths from youth AUD to young adult CUD and youth CUD to young adult AUD were both significant. However, only the cross-lagged path from youth CUD to adult AUD was significant. The cross-lagged paths from young adult AUD to adult CUD and young adult CUD to adult AUD were both nonsignificant. Males and females were mostly similar with only three differences found between genders.

CONCLUSIONS

Comorbidity of AUDs and CUDs was evident from youth through adulthood but the strength of the relationship lessened in adulthood. Temporal sequencing influences of AUDs and CUDs on each other were similar in youth and adulthood but not young adulthood. Same substance stability was greatest in adulthood.

Externalizing behavior and emotion dysregulation are indicators of transmissible risk for substance use disorder

BACKGROUND

Psychological items discriminating children of fathers diagnosed with an illicit drug-related substance use disorder and normal controls are indicators of a unidimensional construct termed transmissible liability index (TLI) (Vanyukov et al., 2009). TLI is a highly heritable (Vanyukov et al., 2009; Hicks, Iacono, McGue, 2012) and valid (Vanyukov et al., 2009; Hicks et al., 2009; Kirisci et al., 2013a) measure of childhood liability to substance use disorders (SUDs).

AIMS

This longitudinal study determined whether TLI has incremental validity for predicting SUD beyond commonly measured psychological indicators of risk.

METHODS

TLI and measures of executive cognitive capacity, emotion dysregulation and externalizing disturbance were administered to boys at ages 10-12 and 16. SUD outcome determined at age 22 was assessed as (1) any SUD, (2) the number of drug-specific SUDs, and (3) SUD severity.

RESULTS

TLI predicted SUD beyond the contribution of measures of emotion dysregulation, executive cognitive capacity and externalizing disturbance. The association of emotion dysregulation and externalizing behavior at ages 10-12 and 16 with SUD at age 22 was also reduced to non-significance after controlling for transmissible risk measured by TLI.

CONCLUSIONS

TLI's incremental validity beyond these latter indicators of risk points to its utility for identifying vulnerable youths requiring intervention.

A Long-Term Longitudinal Examination of the Effect of Early Onset of Alcohol and Drug Use on Later Alcohol Abuse

BACKGROUND

Early onset of alcohol use has been linked to later alcohol problems in adulthood. Currently, it is not clear whether early onset of marijuana and tobacco use similarly predicts alcohol problems. Moreover, most studies examining the effect of early substance use onset on later problems only have followed youth into their early 20s. Therefore, the primary goal of this study was to examine whether early onset of alcohol, marijuana, and tobacco use predicts alcohol problems beyond the transition to adulthood.

METHODS

The sample included 225 15-19-year-old youth (60% girls; 62% Caucasian) who were surveyed in three time periods: 1993-1998 (Time 1), 1998-2003 (Time 2), and 2003-2007 (Time 3). Participants reported their age of onset for regular drinking, tobacco use, and marijuana use. At each time of measurement, they also completed surveys relating to their alcohol use and abuse.

RESULTS

Participants with an earlier age of onset of drinking regularly scored higher on the Michigan Alcoholism Screening Test (MAST) and drank more frequently to get high and drunk throughout their 20s. Tobacco use onset and marijuana use onset were not associated with later alcohol use or abuse.

CONCLUSIONS

Results from this study suggest that the relationship between the onset of substance use and later substance abuse may be substance specific. Of note, early onset of regular drinking was associated with alcohol problems during adulthood, underscoring the importance of delaying the onset of regular alcohol use among youth.

Longitudinal modeling of transmissible risk in boys who subsequently develop cannabis use disorder

BACKGROUND

Risk for substance use disorder is frequently transmitted across generations due to significant heritability.

OBJECTIVE

This longitudinal study tests the hypothesis that initial exposure to cannabis in youths having high transmissible risk is a signal event promoting development of cannabis use disorder (CUD).

METHODS

At age 22, 412 men were classified into three groups: (1) lifetime CUD, (2) cannabis use without CUD, and (3) no lifetime cannabis use. Transmissible risk, quantified on a continuous scale using the previously validated transmissible liability index (TLI), along with cannabis use and CUD were documented at 10-12, 12-14, 16, 19, and 22 years of age.

RESULTS

The CUD group scored higher on the TLI before they began cannabis use compared to the other two groups. In addition, a progressive increase in TLI severity was evinced by the CUD group beginning at the time of initiation of cannabis use whereas cannabis users who did not subsequently develop CUD exhibited a decline in transmissible risk following first exposure.

CONCLUSION

Initial use of cannabis potentiates development of CUD in youths who are at high transmissible risk but is inconsequential in youths having low risk. The practical ramifications of these results for prevention are discussed.