The developmental antecedents of illicit drug use: evidence from a 25-year longitudinal study

Sex-specific associations between co-exposure to multiple metals and externalizing symptoms in adolescence and young adulthood

Externalizing disorders, such as attention-deficit/hyperactivity disorder (ADHD), account for the majority of the child/adolescent referrals to mental health services and increase risk for later-life psychopathology. Although the expression of externalizing disorders is more common among males, few studies have addressed how sex modifies associations between metal exposure and adolescent externalizing symptoms. This study aimed to examine sex-specific associations between co-exposure to multiple metals and externalizing symptoms in adolescence and young adulthood. Among 150 adolescents and young adults (55% female, ages: 15-25 years) enrolled in the Public Health Impact of Metals Exposure (PHIME) study in Brescia, Italy, we measured five metals (manganese (Mn), lead (Pb), copper (Cu), chromium (Cr), nickel (Ni)) in four biological matrices (blood, urine, hair, and saliva). Externalizing symptoms were assessed using the Achenbach System of Empirically Based Assessment (ASEBA) Youth Self-Report (YSR) or Adult Self Report (ASR). Using generalized weighted quantile sum (WQS) regression, we investigated the moderating effect of sex (i.e., assigned at birth) on associations between the joint effect of exposure to the metal mixture and externalizing symptoms, adjusting for age and socioeconomic status. We observed that metal mixture exposure was differentially associated with aggressive behavior in males compared to females (β = -0.058, 95% CI [-0.126, -0.009]). In males, exposure was significantly associated with more externalizing problems, and aggressive and intrusive behaviors, driven by Pb, Cu and Cr. In females, exposure was not significantly associated with any externalizing symptoms. These findings suggest that the effect of metal exposure on externalizing symptoms differs in magnitude between the sexes, with males being more vulnerable to increased externalizing symptoms following metal exposure. Furthermore, our findings support the hypothesis that sex-specific vulnerabilities to mixed metal exposure during adolescence/young adulthood may play a role in sex disparities observed in mental health disorders, particularly those characterized by externalizing symptoms.

Causal factors in childhood and adolescence leading to anabolic-androgenic steroid use: A machine learning approach

Background

Prior research has demonstrated associations between anabolic-androgenic steroid (AAS) use and features from several childhood and adolescent psychosocial domains including body image concerns, antisocial traits, and low levels of parental care. However, prior approaches have been limited by their focus on individual features and lack of consideration of the relevant causal structure.

Methods

We re-analyzed data from a previous cross-sectional cohort study of 232 male weightlifters aged 18-40, of whom 101 had used AAS. These men completed retrospective measures of features from their childhood and early adolescence, including body image concerns, eating disorder psychopathology, antisocial traits, substance use, and family relationships. Using an approach informed by principles of causal inference, we applied four machine-learning methods - lasso regression, elastic net regression, random forests, and gradient boosting - to predict AAS use.

Results

The four methods yielded similar receiver operating curves, mean area under the curve (range 0.66 to 0.72), and sets of highly important features. Features related to adolescent body image concerns (especially muscle dysmorphia symptoms) were the strongest predictors. Other important features were adolescent rebellious behaviors; adolescent feelings of ineffectiveness and lack of interoceptive awareness; and low levels of paternal care.

Conclusions

Applying machine learning within a causally informed approach to re-analyze data from a prior study of weightlifters, we identified six factors (most prominently those related to adolescent body image concerns) as proposed causal factors for the development of AAS use. Compared with the prior analyses, this approach achieved greater methodologic rigor and yielded stronger and broader findings.

Differential associations of adolescent versus young adult cannabis initiation with longitudinal brain change and behavior

Leveraging ~10 years of prospective longitudinal data on 704 participants, we examined the effects of adolescent versus young adult cannabis initiation on MRI-assessed cortical thickness development and behavior. Data were obtained from the IMAGEN study conducted across eight European sites. We identified IMAGEN participants who reported being cannabis-naïve at baseline and had data available at baseline, 5-year, and 9-year follow-up visits. Cannabis use was assessed with the European School Survey Project on Alcohol and Drugs. T1-weighted MR images were processed through the CIVET pipeline. Cannabis initiation occurring during adolescence (14-19 years) and young adulthood (19-22 years) was associated with differing patterns of longitudinal cortical thickness change. Associations between adolescent cannabis initiation and cortical thickness change were observed primarily in dorso- and ventrolateral portions of the prefrontal cortex. In contrast, cannabis initiation occurring between 19 and 22 years of age was associated with thickness change in temporal and cortical midline areas. Follow-up analysis revealed that longitudinal brain change related to adolescent initiation persisted into young adulthood and partially mediated the association between adolescent cannabis use and past-month cocaine, ecstasy, and cannabis use at age 22. Extent of cannabis initiation during young adulthood (from 19 to 22 years) had an indirect effect on psychotic symptoms at age 22 through thickness change in temporal areas. Results suggest that developmental timing of cannabis exposure may have a marked effect on neuroanatomical correlates of cannabis use as well as associated behavioral sequelae. Critically, this work provides a foundation for neurodevelopmentally informed models of cannabis exposure in humans.

Investigating for Whom Brief Substance Use Interventions Are Most Effective: An Individual Participant Data Meta-analysis

Prior research suggests that brief interventions (BIs) for alcohol and other drug use may vary in effectiveness across patient sociodemographic factors. The objective of this individual participant data (IPD) meta-analysis was to explore for whom BIs delivered in general healthcare settings are more or less effective. We examined variability in BI effects by patient age, sex, employment, education, relationship status, and baseline severity of substance use using a two-stage IPD meta-analysis approach. All trials included in a parent aggregate data meta-analysis (k = 116) were invited to contribute IPD, and 29 trials provided patient-level data (12,074 participants). Among females, BIs led to significant reductions in binge alcohol consumption ([Formula: see text] = 0.09, 95% CI [0.03, 0.14]), frequency of alcohol consumption ([Formula: see text] = 0.10, 95% CI [0.03, 0.17]), and alcohol-related consequences ([Formula: see text] = 0.16, 95% CI [0.08, 0.25]), as well as greater substance use treatment utilization ([Formula: see text] = 0.25, 95% CI [0.21, 0.30]). BIs yielded larger reductions in frequency of alcohol consumption at 3-month follow-up for individuals with less than a high school level education ([Formula: see text] = 0.16, 95% CI [0.09, 0.22]). Given evidence demonstrating modest BI effects on alcohol use and mixed or null findings for BI effects on other drug use, BI research should continue to investigate potential drivers of effect magnitude and variation.  PROTOCOL REGISTRATION DETAILS: The protocol for this review was pre-registered in PROSPERO #CRD42018086832 and the analysis plan was pre-registered in OSF: osf.io/m48g6.

Deconstructing the heterogeneity of alcohol use disorder: lifetime comorbid non-alcohol substance use disorder as a distinct behavioral phenotype?

BACKGROUND

Alcohol use disorder (AUD) is an etiologically and clinically heterogeneous condition. Accumulating evidence suggests that persons with lifetime histories of comorbid AUD and non-alcohol substance use disorder (DRUG) constitute an important subgroup of AUD. This study evaluated the distinctiveness of the comorbid AUD/DRUG behavioral phenotype in a community sample with respect to risk factors, AUD course features, and outcome variables assessed at age 30. Contrast groups included persons with histories of AUD only, DRUG only, and neither AUD nor DRUG.

METHODS

This research utilized a prospective study design with an age-based cohort (n = 732). Participants completed four comprehensive diagnostic evaluations during the high-risk periods of adolescence, emerging adulthood, and young adulthood.

RESULTS

The comorbid AUD/DRUG group was distinguished from the AUD only group by risk factors, AUD course features, and outcomes. Group differences in outcomes were also explained by overall substance use disorder (SUD) severity. Persons with AUD/DRUG comorbidity were indistinguishable from those with DRUG only histories with respect to risk factors and outcomes but demonstrated greater overall SUD severity. Persons with AUD only were indistinguishable from those with neither AUD nor DRUG histories in risk factor endorsements and were mostly similar in outcomes.

CONCLUSIONS

Findings collectively suggest that young adults with histories of AUD only and those with comorbid AUD/DRUG are drawn from dissimilar populations. Similarities between the AUD only group with those absent AUD or DRUG histories are likely related to the former group's developmentally limited AUD course accompanied by relatively few or short-lived alcohol-related problems.

E-cigarettes may serve as a gateway to conventional cigarettes and other addictive drugs

Electronic cigarettes (e-cigarettes) are devices that allow the user to inhale nicotine in a vapor, and are primarily marketed as a means of quitting smoking and a less harmful replacement for traditional cigarette smoking. However, further research is needed to determine if vaping nicotine via e-cigarettes can be effective. Conversely, nicotine has been considered a gateway drug to alcohol and other addictive drugs and e-cigarettes containing nicotine may have the same effects. Previous reports have shown that e-cigarette use may open the gate for the use of other drugs including conventional cigarettes, cannabis, opioids, etc. The increasing prevalence of e-cigarettes, particularly among youth and adolescents in the last decade have led to an increase in the dual use of e-cigarettes with alcohol, cannabis, and other illicit drug use like heroin and 3-4-methylenedioxymethamphetamine (MDMA). The advent of e-cigarettes as a device to self-administer addictive agents such as cocaine and synthetic cathinones may bring about additional adverse health effects associated with their concurrent use. This review aims to briefly describe e-cigarettes and their different generations, and their co-use with other addictive drugs as well as the use of the device as a tool to self-administer addictive drugs, such as cocaine, etc.

Predictors of methamphetamine use in a longitudinal birth cohort

BACKGROUND

Identifying predictors of methamphetamine use can inform population prevention strategies.

METHODS

Participants (n = 1265) born in Christchurch, New Zealand were followed from birth to age 40. Methamphetamine outcomes (any use since the last interview, and regular use, defined as any period of at least weekly use) were ascertained by self-report at six interviews from age 18 to 40. Predictors with plausible associations with methamphetamine use were extracted from the study database. These were grouped into early predictors (age 0-16), comprising childhood, familial and individual characteristics; and later time-dynamic correlates of methamphetamine use in adulthood (ages 16-40). Generalised estimating equation models were fitted to identify predictors of methamphetamine use outcomes.

RESULTS

In adjusted models, paternal overprotectiveness and childhood anxious / withdrawn behavior were associated with any use of methamphetamine, but not regular use. Conversely, childhood conduct problems and parental illicit drug were associated with regular use but not any use. Male sex, high novelty seeking and deviant peer affiliations were associated with both any use and regular use in adjusted models. The strongest correlates of methamphetamine use in adulthood were unemployment, life stress and other substance use disorders (cannabis, nicotine, and alcohol).

CONCLUSION

Markers of externalizing problems in childhood and adolescence (conduct problems, high novelty seeking, parental illicit substance use, and deviant peer affiliations) are the strongest predictors of regular methamphetamine use in adulthood.

Illicit drug use in university students in the UK and Ireland: a PRISMA-guided scoping review

BACKGROUND

Interest in the health and well-being of university students has increased in the UK and Ireland in the past two decades as their numbers have grown. Recent high-profile deaths of students after using illicit drugs have highlighted the importance of the topic for policy makers. This scoping review maps the state of the existing literature evaluating use of illicit drugs in university students in the UK and Ireland. It aims to highlight research gaps and inform policy.

METHOD

We conducted a systematic search of papers related to psychoactive drug use in university students in the UK and Ireland published before August 2021. The 18 extracted study characteristics included author(s); year of publication; journal; location of data collection; study design; delivery method (e.g., online survey, in-person, postal survey); number of participants; response rate; participant course of study, year of study, degree level (i.e., undergraduate, postgraduate), gender and age; time-period assessed (e.g., lifetime, current use, past 12 months); primary aim; primary outcome; ethical approval; and funding source.

RESULTS

The PRISMA-guided search strategy identified 1583 papers for abstract review; of 110 papers retained for full-text review, 54 studies met criteria for inclusion for this paper. Primary outcomes were coded into five groups: prevalence and patterns of drug use; factors associated with drug use; attitudes and knowledge about, and motivation for, drug use; supply of drugs; consequences of drug use. The results show that there is no coherent body of research in this area. The prevalence of reported drug use has crept up and the range of substances reported has broadened over time, and attitudes to drugs on average have normalised. However, there are significant methodological limitations that limit the utility of these findings. There was little evidence of published work on prevention of, or intervention to reduce, drug-related harms.

CONCLUSION

The domains identified offer a framework for university administrators, researchers and policy makers to understand the potential response to drug use in university students in the UK and Ireland. Recommendations are made to fill the gaps in the research evidence base.

The relative and interactive impact of multiple risk factors in schizophrenia spectrum disorders: a combined register-based and clinical twin study

BACKGROUND

Research has yielded evidence for genetic and environmental factors influencing the risk of schizophrenia. Numerous environmental factors have been identified; however, the individual effects are small. The additive and interactive effects of multiple risk factors are not well elucidated. Twin pairs discordant for schizophrenia offer a unique opportunity to identify factors that differ between patients and unaffected co-twins, who are perfectly matched for age, sex and genetic background.

METHODS

Register data were combined with clinical data for 216 twins including monozygotic (MZ) and dizygotic (DZ) proband pairs (one or both twins having a schizophrenia spectrum diagnosis) and MZ/DZ healthy control (HC) pairs. Logistic regression models were applied to predict (1) illness vulnerability (being a proband v. HC pair) and (2) illness status (being the patient v. unaffected co-twin). Risk factors included: A polygenic risk score (PRS) for schizophrenia, birth complications, birth weight, Apgar scores, paternal age, maternal smoking, season of birth, parental socioeconomic status, urbanicity, childhood trauma, estimated premorbid intelligence and cannabis.

RESULTS

The PRS [odds ratio (OR) 1.6 (1.1-2.3)], childhood trauma [OR 4.5 (2.3-8.8)], and regular cannabis use [OR 8.3 (2.1-32.7)] independently predicted illness vulnerability as did an interaction between childhood trauma and cannabis use [OR 0.17 (0.03-0.9)]. Only regular cannabis use predicted having a schizophrenia spectrum diagnosis between patients and unaffected co-twins [OR 3.3 (1.1-10.4)].

CONCLUSION

The findings suggest that several risk factors contribute to increasing schizophrenia spectrum vulnerability. Moreover, cannabis, a potentially completely avoidable environmental risk factor, seems to play a substantial role in schizophrenia pathology.

Risk Factors for Substance Use across the Lifespan

Substance use is a perennial public health concern with associated health risks and economic impacts on society. In this article, we present a selective review of the epidemiological and clinical literatures on alcohol and substance use from a lifespan developmental perspective. We compare and contrast risk factors for the initiation of use and the development of a substance use disorder in adolescence, young adulthood, middle-age and later life. During adolescence, alcohol use experimentation is at its peak. Specific risk factors have been identified including trauma and parenting style that can increase the risk of substance use for teenagers. Emerging adults and college students are likely to experiment with other substances in addition to alcohol such as nicotine, marijuana, cocaine, and prescription medication such as Adderall. Middle-age and older adults with alcohol and substance use in their developmental histories may have an undiagnosed alcohol use disorder. Others will develop a late-onset substance use disorder in older age, possibly due to a dearth of social support, coping with bereavement, and medical complication. Based on Social Cognitive Theory, the roles of expectancies and self-efficacy are hypothesized to impact substance use and the risk of substance use disorder across the lifespan. Implications of the present review for future research on age-specific risk factors in alcohol use in relation to underlying developmental processes are considered.

Coping motives mediate the relationship between PTSD and MDMA use in adolescents with substance use disorders

BACKGROUND

Post-traumatic stress disorder (PTSD) and substance use disorders (SUDs) often co-occur in adolescent patients. Previous research has shown that these patients differ from SUD patients without PTSD in terms of their substance use patterns. In this study, we aimed to test whether substance use in this population is related to an attempt to self-medicate PTSD-related symptoms.

METHODS

German adolescent patients (aged 13-18 years) at an outpatient clinic for SUD treatment, n = 111 (43% female), completed a self-designed questionnaire on use motives, a measure of PTSD-related experiences, and underwent a standardized psychiatric interview including structured substance use questions. Participants were subsequently classified as 'no traumatic experiences ('noTEs' but SUD), 'traumatic experiences but no current PTSD diagnosis' ('TEs' with SUD), and 'PTSD' with SUD. After establishing a self-designed motive measurement through exploratory and confirmatory factor analyses, we calculated non-parametric group differences and a mediation analysis in a linear regression framework.

RESULTS

The past-year frequency of MDMA use was highest in the PTSD group and lowest in the noTE group (H (2) = 7.2, p = .027, η2 = .058), but no differences were found for frequencies of tobacco, alcohol, cannabis, or stimulant use (all H ≤ 4.9, p ≥ .085, η2 ≤ .033). While controlling for sex, the three groups showed a similar pattern (highest in the PTSD group and lowest in the noTE group) for coping scores (F (103) = 5.77, p = .004, η2 = .101). Finally, mediation analyses revealed an indirect effect of coping score (b = 0.61, 95% CI [0.29, 1.58], p = .145) on the association between group membership and MDMA use frequency.

CONCLUSIONS

In adolescent SUD patients, we found an association of current PTSD and lifetime traumatic experiences with higher MDMA use that could be partially explained by substance use being motivated by an attempt to cope with mental health symptoms. This indicates a coping process involved specifically in MDMA use compared to the use of other psychoactive substances, possibly due to unique psychoactive effects of MDMA.

Associations between parenting characteristics and adolescent substance use: A genetically informed, longitudinal adoption study

The present study examined putative environmental predictors of adolescent substance use, using a prospective adoption design to distinguish between environmental mediation (i.e., parenting influencing adolescent substance use), passive gene-environment correlation (i.e., parental genetic predisposition influencing the association between parenting characteristics and adolescent substance use), and evocative gene-environment correlation (i.e., children's genetic predisposition influencing parenting). Longitudinal data from the Colorado Adoption Project (395 adoptees, 491 nonadoptees, 485 adoptive parents, and 490 biological parents) were examined. Children (48% girls) were assessed at ages 1 to 17 years. Over 90% of the sample were non-Hispanic White. Associations between parenting and adolescent substance use were compared between adoptive and nonadoptive families. Positive, negative, and inconsistent parenting measures in early childhood through adolescence were not consistently associated with adolescent substance use, with only 6% of correlations being statistically significant (r = -0.152 to .207). However, parent-child relationship quality assessed from childhood to adolescence and orientation to parents assessed during adolescence were significantly, negatively associated with adolescent substance use, with 71% of correlations being statistically significant (r = -0.88 to -0.11). There was little evidence of sex differences in the associations. Environmental mediation, rather than passive or evocative gene-environment correlation, explained most associations.

Evidence on the acute and residual neurocognitive effects of cannabis use in adolescents and adults: a systematic meta-review of meta-analyses

BACKGROUND

Cannabis is among the most consumed psychoactive substances world-wide. Considering changing policy trends regarding the substance, it is crucial to understand more clearly its potential acute and residual adverse effects from a public health viewpoint. Cognitive function is one of the targeted areas with conflicting findings. This meta-review measured the magnitude of acute and residual effects of cannabis on cognition in adolescents and adults provided by meta-analyses and evaluated quality of evidence.

METHODS

A systematic search was performed in PubMed, PsycINFO, Web of Science and Google Scholar. Meta-analyses were included if they quantitatively examined the performances of users from the general population on cognitive tasks.

RESULTS

The search retrieved 10 eligible meta-analyses (71 effects sizes, n = 43 761) with evidence ranging from low to moderate quality, which were categorized into domains of cognitive functions: executive functions (k = 7), learning and memory (k = 5), attention (k = 4), processing speed (k = 5), perceptual motor function (k = 2) and language (k = 2). Verbal learning and memory displayed the most robust evidence and were most impaired by acute cannabis intoxication that persisted after intoxication passed. Small-to-moderate acute and residual   adverse effects were reported for executive functioning. Cannabis use led to small deficits in inhibitory processes and flexibility, whereas small-to-moderate deficits were reported for working memory and decision-making. Evidence regarding processing speed and attention has shown that cannabis administration induced small-to-moderate adverse effects and residual neurocognitive deficits were observed in heavy cannabis-using youths. Results showed no significant difference between cannabis users and non-users on language, and small-to-moderate effects for simple motor skills.

CONCLUSION

Meta-analytical data on the acute effects of cannabis use on neurocognitive function have shown that cannabis intoxication leads to small to moderate deficits in several cognitive domains. These acute impairments accord with documented residual effects, suggesting that the detrimental effects of cannabis persist beyond acute intake.

Alcohol Misuse among English Youth, Are Harms Attributable to Alcohol or to Underlying Disinhibitory Characteristics?

INTRODUCTION

Alcohol use by young people is associated with a range of psychological and physical harms. However, similar harms are also reported with disinhibitory conditions such as conduct problems that are said to precede and predispose to alcohol misuse. We explored whether alcohol use or indicators of underlying disinhibition predict psychological and physical harms in a cohort of young people.

METHODS

We used data from a randomised controlled intervention trial that identified young people who consumed alcohol (n = 756), mean age = 15.6 years, attending emergency departments (EDs) in England. Disinhibition was measured by the self-report Strengths and Difficulties Questionnaire hyperactivity and conduct problem items, and alcohol-related harms by questions from the ESPAD, a major European school survey. We conducted a mediation analysis with a primary outcome of frequency of engaging in alcohol-related harms 12 months after screening in ED, exploring for the mediating influence of alcohol consumed at six months. We included age, gender, allocated group and baseline consumption as covariates and adjusted for the multi-level nature of the study, where young people were nested within EDs.

RESULTS

Conduct problems and to a lesser extent hyperactivity predicted harms at twelve months. This effect was not mediated by alcohol consumed at 6 months.

CONCLUSIONS

Among young drinkers underlying behavioural attributes predict harm independently of alcohol use. This suggests that the harms associated with alcohol use are attributable more to underlying disinhibitory characteristics than the quantity of alcohol consumed.

Assessing the Association Between Internet Addiction Disorder and Health Risk Behaviors Among Adolescents and Young Adults: A Systematic Review and Meta-Analysis

Background

Internet addiction disorder (IAD) is a global issue that has resulted in a slew of physical and emotional consequences. Studies have indicated that health risk behaviors might be the risk factors for IAD. The published literature on the correlation between the two is lacking. Therefore, we conducted a comprehensive analysis to understand better the link between IAD and health risk behaviors among adolescents and young adults.

Methods

We searched ten electronic databases for relevant articles. Data were extracted based on IAD and health risk behaviors ( alcohol, smoking, suicidal, gambling and drug abuse). We calculated odds ratios (ORs), a pooled correlation coefficient (r) and 95% confidence intervals (CIs). A fixed-effect model was applied to summarize the pooled effects. Heterogeneity was examined using I2 statistics and Cochran's Q statistics. All analyses were conducted by using Stata version 15.0.

Results

A total of 16 studies and 61,823 participants were included in this study. Meta-analysis showed that IAD was positively correlated with drinking (r = 0.35; 95% CI 0.32–0.37) and smoking (r = 0.12; 95%CI 0.10–0.15), and was associated with an increased risk of suicidal behavior (OR= 1.95; 95% CI 1.65–2.30), drinking (OR= 1.75; 95% CI 1.65–1.85), and smoking (OR= 1.63; 95% CI 1.54–1.72) among adolescents.

Conclusion

We found significantly increased risks of suicidal behavior, drinking, and smoking in adolescents and young adults with IAD. These findings are important to expand our understanding of IAD and have great guiding significance for preventing health risk behaviors of adolescents and young adults.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021257729, identifier: PROSPERO CRD42021257729.

An assessment of executive function in two different rat models of attention-deficit hyperactivity disorder: Spontaneously hypertensive versus Lphn3 knockout rats

Attention-deficit/hyperactivity disorder (ADHD) a common neurodevelopmental disorder of childhood and often comorbid with other externalizing disorders (EDs). There is evidence that externalizing behaviors share a common genetic etiology. Recently, a genome-wide, multigenerational sample linked variants in the Lphn3 gene to ADHD and other externalizing behaviors. Likewise, limited research in animal models has provided converging evidence that Lphn3 plays a role in EDs. This study examined the impact of Lphn3 deletion (i.e., Lphn3-/- ) in rats on measures of behavioral control associated with externalizing behavior. Impulsivity was assessed for 30 days via a differential reinforcement of low rates (DRL) task and working memory evaluated for 25 days using a delayed spatial alternation (DSA) task. Data from both tasks were averaged into 5-day testing blocks. We analyzed overall performance, as well as response patterns in just the first and last blocks to assess acquisition and steady-state performance, respectively. "Positive control" measures on the same tasks were measured in an accepted animal model of ADHD-the spontaneously hypertensive rat (SHR). Compared with wildtype controls, Lphn3-/- rats exhibited deficits on both the DRL and DSA tasks, indicative of deficits in impulsive action and working memory, respectively. These deficits were less severe than those in the SHRs, who were profoundly impaired on both tasks compared with their control strain, Wistar-Kyoto rats. The results provide evidence supporting a role for Lphn3 in modulating inhibitory control and working memory, and suggest additional research evaluating the role of Lphn3 in the manifestation of EDs more broadly is warranted.

Parenting and Home Environment in Childhood and Adolescence and Alcohol Use Disorder in Adulthood

PURPOSE

Parenting is a modifiable factor affecting the development of alcohol use disorder (AUD); however, the persistence of this effect into adulthood remains poorly understood. This study aimed to explore the longitudinal relationship between positive parenting and AUD in adulthood.

METHODS

Data were gathered from the Christchurch Health and Development Study (CHDS), a birth cohort of 1,265 children born in Christchurch (New Zealand) in mid-1977. Positive parenting was quantified to age 16, and included the extent to which cohort members self-reported: high scores on measures of maternal and paternal care; low scores on a measure of maternal and paternal overprotection; high scores on a measure of parental attachment; low scores on a measure of parental intimate partner violence; and occasional or no use of physical punishment. Outcome measures were AUD incidence and symptoms at ages 15-35, with potential confounding factors and time-dynamic covariates included.

RESULTS

There was a significant association between positive parenting and AUD outcomes, with higher levels of positive parenting associated with a lower incidence of AUD and AUD symptoms. Controlling for confounding factors reduced the association between positive parenting and AUD outcomes, but they remained statistically significant. Adjustment for mental health, life stress, and employment reduced the magnitude of the association between positive parenting and alcohol outcomes to statistical nonsignificance.

CONCLUSIONS

Parenting factors in childhood and adolescence are linked to AUD outcomes in adulthood, as well as mental health, substance use, and life stress. Investment in positive parenting in adolescence may reduce AUD and associated harms in adulthood.

General risks of harm with cannabinoids, cannabis, and cannabis-based medicine possibly relevant to patients receiving these for pain management: an overview of systematic reviews

ABSTRACT

The growing demand for improved pain treatments together with expanding legalization of, and access to, cannabinoids, cannabis, and cannabis-based medicines has intensified the focus on risk-benefit considerations in pain management. Given limited harms data from analgesic clinical trials, we conducted an overview of systematic reviews focused on all harms possibly relevant to patients receiving cannabinoids for pain management. This PROSPERO-registered, PRISMA-compliant systematic overview identified 79 reviews, encompassing over 2200 individual reports about psychiatric and psychosocial harms, cognitive/behavioral effects, motor vehicle accidents, cardiovascular, respiratory, cancer-related, maternal/fetal, and general harms. Reviews, and their included studies, were of variable quality. Available evidence suggests variable associations between cannabis exposure (ranging from monthly to daily use based largely on self-report) and psychosis, motor vehicle accidents, respiratory problems, and other harms. Most evidence comes from settings other than that of pain management (eg, nonmedicinal and experimental) but does signal a need for caution and more robust harms evaluation in future studies. Given partial overlap between patients receiving cannabinoids for pain management and individuals using cannabinoids for other reasons, lessons from the crisis of oversupply and overuse of opioids in some parts of the world emphasize the need to broadly consider harms evidence from real-world settings. The advancement of research on cannabinoid harms will serve to guide optimal approaches to the use of cannabinoids for pain management. In the meantime, this evidence should be carefully examined when making risk-benefit considerations about the use of cannabinoids, cannabis, and cannabis-based medicine for chronic pain.

Intergenerational Continuity and Discontinuity in Substance Use: The Role of Concurrent Parental Marijuana Use

PURPOSE

This study examines whether parental marijuana use that occurs during the life of a child impacts patterns of continuity and discontinuity in adolescent substance use among father-child dyads.

METHODS

The study uses data from 263 father-child-mother triads involved in the Rochester Youth Development Study (RYDS) and the Rochester Intergenerational Study (RIGS). We use a dual trajectory model is used to examine the research questions.

RESULTS

Results suggest that both paternal and maternal marijuana use during the child's life increase the probability that a child will follow a moderate or high substance use trajectory during adolescence, beyond the risk incurred from paternal adolescent history of substance use. Some nuances related to the timing of concurrent parental marijuana use emerge across parent sex.

CONCLUSION

Concurrent parental marijuana use predicts child's substance use beyond a parent's prior substance use history. The results highlight the important role of both caregivers in the explanation of patterns of discontinuity across generations, as well as the relevance of considering when the use occurred.

An Emerging Substance Use Epidemic: Recreational Use of HIV Pre-Exposure Prophylaxis and Treatment in South Africa

South Africa has the largest HIV burden and treatment program in the world. Diversion of HIV prevention and treatment medication for recreational use-or nonmedical use for psychoactive effects-is a public health concern globally and in South Africa. Few South African studies examine recreational use of HIV antiretrovirals (ARVs). The objective of this article is to evaluate the prevalence of recreational ARV use and to identify risk and protective factors associated with use. Data are drawn from a cross-sectional household survey of N = 4399 adolescent girls and young women (AGYW) aged 15-24 years in six districts across South Africa where an evaluation of a South African combination HIV prevention for girls and young women was implemented. The use of ARVs to "get high" was reported by 8.3% of AGYW across all districts. Logistic regressions showed that those engaging in transactional sex were at two times higher odds of recreational ARV use [adjusted odds ratio (aOR) = 2.01; confidence interval (95% CI): 1.51-2.68]. Recreational ARV use was more likely among those who used pre-exposure prophylaxis (PrEP) (aOR = 2.17; 95% CI: 1.36-3.48); HIV-positive participants who were not on ARVs for treatment (aOR = 0.36; 95% CI: 0.18-0.68); and those who were not virally suppressed (aOR, no vs. yes = 2.84; 95% CI: 1.21-6.66). As ARVs become more widely available for prevention and treatment, it will be important to monitor and address the possible emergence of ARVs as a substance for misuse or abuse.

Automatic cognitions as mediators of parental influence on adolescent cannabis use

AIMS

Multiple social influences affect cannabis use in adolescents, including parental and peer cannabis use norms. However, the mechanisms of influence underlying these social influences remain unclear. Recent studies have suggested that cognitions about cannabis use and the effects of cannabis may mediate social influences. The current study explored the relationship between automatic self-generated cognitions and their relationship with parental influences on cannabis use in a sample of n = 675 11 to 16-year-old adolescents over three years (Mean Age: 13.96, SD = 0.88, 56.4% female).

METHODS

Participants reported perceptions of parental cannabis use and completed a cannabis word association task (CWAT), an open-ended cannabis outcome expectancy liking (COEL) task, and measures of cannabis use in the past year.

RESULTS

Perceived parental use did not directly predict cannabis use two years later. However, a latent construct loading on both CWAT and COEL scores strongly predicted cannabis use over the following year. Structural modelling demonstrated that the association between previous cannabis use and parental cannabis use and adolescents' cannabis use over the next two years was fully mediated by cognitions.

CONCLUSION

The results of the study are discussed and interpreted through the lens of dual-process theories.

Cannabis use and cannabis use disorder

Cannabis use disorder (CUD) is an underappreciated risk of using cannabis that affects ~10% of the 193 million cannabis users worldwide. The individual and public health burdens are less than those of other forms of drug use, but CUD accounts for a substantial proportion of persons seeking treatment for drug use disorders owing to the high global prevalence of cannabis use. Cognitive behavioural therapy, motivational enhancement therapy and contingency management can substantially reduce cannabis use and cannabis-related problems, but enduring abstinence is not a common outcome. No pharmacotherapies have been approved for cannabis use or CUD, although a number of drug classes (such as cannabinoid agonists) have shown promise and require more rigorous evaluation. Treatment of cannabis use and CUD is often complicated by comorbid mental health and other substance use disorders. The legalization of non-medical cannabis use in some high-income countries may increase the prevalence of CUD by making more potent cannabis products more readily available at a lower price. States that legalize medical and non-medical cannabis use should inform users about the risks of CUD and provide information on how to obtain assistance if they develop cannabis-related mental and/or physical health problems.

Early-life stress exacerbates the effects of WIN55,212-2 and modulates the cannabinoid receptor type 1 expression

Early-life stress induces an abnormal brain development and increases the risk of psychiatric diseases, including depression, anxiety and substance use disorders. We have developed a reliable model for maternal neglect, named maternal separation with early weaning (MSEW) in CD1 mice. In the present study, we evaluated the long-term effects on anxiety-like behaviours, nociception as well as the Iba1-positive microglial cells in this model in comparison to standard nest (SN) mice. Moreover, we investigated whether MSEW alters the cannabinoid agonist WIN55,212-2 effects regarding reward, spatial and emotional memories, tolerance to different cannabinoid responses, and physical dependence. Adult male offspring of MSEW group showed impaired responses on spatial and emotional memories after a repeated WIN55,212-2 treatment. These behavioural impairments were associated with an increase in basolateral amygdala and hippocampal CB1-expressing fibres and higher number of CB1-containing cells in cerebellum. Additionally, MSEW promotes a higher number of Iba1-positive microglial cells in basolateral amygdala and cerebellum. As for the cannabinoid-induced effects, rearing conditions did not influence the rewarding effects of WIN55,212-2 in the conditioned place preference paradigm. However, MSEW mice showed a delay in the development of tolerance to the cannabinoid effects. Moreover, CB1-positive fibres were reduced in limbic areas in MSEW mice after cannabinoid withdrawal precipitated with the CB1 antagonist SR141617A. These findings support that early-life stress promotes behavioural and molecular changes in the sensitivity to cannabinoids, which are mediated by alterations in CB1 signalling in limbic areas and it induces an increased Iba1-microglial marker which could interfere in emotional memories formation.

Past Year Cannabis Use Among Norwegian Adolescents: Time Trends Based on the Ungdata Surveys 2010-2019

Aims: To describe trends in cannabis use from 2010 to 2019 among Norwegian adolescents and relate these to individual- and municipal-level variables. Design: Data from nationwide repeated cross-sectional surveys collected in 2010-2013 (T1), 2014-2016 (T2), and 2017-2019 (T3) were used to describe secular trends in proportions of adolescent cannabis use. Setting: Cross-sectional surveys in 410 of the total 428 municipalities of Norway. Participants: A total of 628,678 survey responses from adolescents aged ~13-19 years of age, in which 566,912 survey responses were eligible for analyses, representing data from 340 municipalities. Measurements: Respondent's past year cannabis use, time, gender, school grade, municipality, geographical location, and municipality population. Findings: Boys reported overall higher cannabis use, with ~2:1 gender ratio for any past year cannabis use and a 3:1 gender ratio for frequent cannabis use. Adolescents in Eastern Norway reported higher cannabis use compared with other areas in the country, and adolescents from municipalities with a higher population size reported higher rates of cannabis use than smaller municipalities. A gradual increase in cannabis use from T1 to T3 was found in Eastern Norway and in the largest municipalities. More generally, proportions of past year cannabis use showed a marked increase from T2 to T3 across genders, grade/age groups, geographical location, and municipality population, with few exceptions. Conclusions: Our findings indicate that proportions of past year cannabis use have increased among Norwegian adolescents in recent years. Preventive interventions to hinder initiation of cannabis use, as well as measures to address frequent cannabis use among Norwegian adolescents, are needed.

Psychosocial and socio-environmental factors associated with adolescents' tobacco and other substance use in Bangladesh

BACKGROUND

Tobacco, alcohol, and marijuana are the top three substances used by adolescents. The adverse health effects of these three substances are well documented in epidemiological literature, yet little is known about the substance use and associated factors among adolescents in Bangladesh. This study examines the risk factors for tobacco and other substances use among school-going adolescents in Bangladesh.

METHODS

We analyzed data from the 2014 Bangladesh Global School-based Student Health Survey (GSHS) of adolescents aged 13-17 years. We used two outcome measures: tobacco use (TU) and other substance use (SU; alcohol and/or marijuana). We examined a set of reported psychosocial and socio-environmental adverse events as risk factors. Logistic regression analyses were used to identify associations.

RESULTS

The prevalence of TU and other SU among school-going adolescents was 9.6% and 2.3%, respectively. The likelihood of TU and other SU was higher among adolescents who reported being bullied (TU: adjusted odd ratio [AOR]: 1.93; 95% confidence interval [CI]: 1.24-3.00; and other SU: AOR: 3.43; 95% CI: 1.46-7.99) and having sexual history (TU: AOR: 19.38; 95% CI: 12.43-30.21; and other SU: AOR: 5.34; 95% CI: 2.17-13.29). Moreover, anxiety-related sleep loss was associated with adolescents' TU (AOR: 2.41; 95% CI: 1.02-5.82) whereas the likelihood of other SU (AOR: 3.27; 95% CI: 1.14-9.44) was higher among lonely adolescents. Experience of adverse socio-environmental factors, such as parental substance use (TU: AOR: 7.81; 95% CI: 5.08-12.01), poor monitoring (TU: AOR: 1.96; 95% CI: 1.16-3.31) and poor understanding (TU: AOR: 2.22; 95% CI: 1.36-3.65), and lack of peer support (TU: AOR: 3.13; 95% CI: 1.84-5.31; and other SU: AOR: 2.45; 95% CI: 1.02-5.91), and truancy (other SU: AOR: 4.29; 95% CI: 1.81-10.12) were also positively associated with TU and/or other SU. Additionally, higher odds of tobacco use were observed among adolescents who reported 1 (AOR: 4.36 times; 95% CI: 1.34-14.24), 2 (AOR: 8.69 95% CI: 1.67-28.23), and ≥3 (AOR: 17.46; 95% CI: 6.20-49.23) adverse psychosocial experiences than who did not report any psychosocial events.

CONCLUSIONS

Tobacco and other substance use among school-going adolescents are prevalent in Bangladesh. Several psychosocial and socio-environmental events are associated with TU and other SU, which should be incorporated into adolescent substance use and health promotion programs.

Alcohol use in adolescents and adult psychopathology and social outcomes: Findings from a 35-year cohort study

OBJECTIVE

To examine the consequences of alcohol consumption and symptoms of alcohol use disorder during adolescence and later adulthood psychopathology and social outcomes.

METHODS

A longitudinal, prospective birth cohort study, the Christchurch Health and Development Study, was examined across a 35-year period. We estimated the associations between two measures of adolescent alcohol use (volume of alcohol consumed and symptoms of alcohol use disorder) and two later internalising disorders, externalising psychopathology measured by substance use disorders and psychosocial outcomes in adulthood, adjusting for individual and family factors from childhood.

RESULTS

The pattern of results indicates alcohol symptoms predict internalising disorder in adulthood. Volume of alcohol used in adolescence predicted adult substance use disorders, lower educational attainment and higher risk of welfare benefit receipt in adulthood in fully adjusted models.

CONCLUSION

Early consumption of larger volumes of alcohol led to continuation of this pattern in adult life with resulting poorer educational achievement, increased welfare benefit receipt and substance use disorders. Early symptoms of alcohol use disorder, however, led to increased adult levels of mental health disorders. This relationship persisted within a 20-year study period and after adjustment for statistically significant covariate factors. The study shows that early patterns of alcohol use have a direct and specific impact upon adult outcomes.

Association of E-cigarettes with adolescent alcohol use and binge drinking-drunkenness: A systematic review and meta-analysis

Background: E-cigarette (ECIG) use has increased substantially in the past decade. Co-use of alcohol and ECIGS may have serious consequences in adolescents. Objectives: To evaluate the association of e-cigarettes (ECIGs) with alcohol use in adolescents. Methods: Searched databases included PubMed, EMBASE, CINAHL, PsycINFO, Web of Science, and gray literature. Studies were included if they contained a non-E-cigarette group (NON-ECIG), an ECIG group, detailed rates of alcohol use, binge drinking, or drunkenness and included adolescents. Two independent reviewers extracted data using MOOSE guidelines. Evidence quality across studies was assessed using Cochrane GRADE methodology. Summary effects of ECIG vs. NON-ECIG use on any alcohol use and a composite of binge drinking/drunkenness were calculated using a random-effects model. Results: 28 of 3768 initially identified studies were included: 25 cross-sectional, 3 cohort studies, N = 458,357 total subjects (49.6% females). Pooling of data showed that ECIG users had a higher risk for any alcohol use compared to NON-ECIG users (Odds Ratio/OR 6.62, 95% confidence interval/CI 5.67-7.72) and a higher rate of binge drinking/drunkenness compared to NON-ECIG users (OR 6.73, 95% CI 4.5 - 10.07). The subset of high school ECIG users had higher rates of alcohol use (OR 8.17, 95% CI 5.95-11.2) and binge drinking/drunkenness (OR 7.98, 95% CI 5.98-10.63) compared to NON-ECIG users. Conclusion: ECIG users had a higher risk of alcohol use and binge drinking/drunkenness compared to NON-ECIG users. Our findings indicate that interventions to reduce ECIG use should be coupled with measures to reduce alcohol use in adolescents.Abbreviations: ECIG: e-cigarettes; NON-ECIG: non e-cigarettes.

Exploring how Family and Neighborhood Stressors Influence Genetic Risk for Adolescent Conduct Problems and Alcohol Use

Previous research suggests that genetic risk factors may predispose to conduct problems and alcohol use in adolescence. Whether genetic risk factors interact with social contexts has not been well characterized among African American adolescents. Data came from a subsample of the Genes, Environment, and Neighborhood Initiative study comprising 501 African American adolescents, including 151 lifetime drinkers (56% female, mean age = 16.3, SD = 1.4). Genetic risk was assessed with polygenic risk scores for alcohol dependence. Analyses explored interactions between genetic risk and self-reported alcohol use, conduct problems, life stressors, and other covariates. The effects of two gene-environment interactions (G × E) were tested in the sample of alcohol exposed adolescents; one on conduct problems and the other on alcohol use. There were significant associations between polygenic risk for alcohol dependence and conduct problems. A significant G × E interaction showed the impact of genetic risk on conduct problems was stronger under conditions of high exposure to family and neighborhood stressors. Among this sample of African American adolescents, genetic risk for alcohol dependence was not directly associated with alcohol use but was related to more conduct problems. Further, the effect of genetic risk interacted with stressors from the family and neighborhood, so that the effect of genetic risk on conduct problems was stronger for individuals who reported greater stressors.

Cannabis use, subsequent other illicit drug use and drug use disorders: A 16-year follow-up study among Swedish adults

AIMS

To examine the association between cannabis use and subsequent other illicit drug use and drug use disorders (harmful use and dependence).

DESIGN, SETTING, PARTICIPANTS

We used survey data from a population-based cohort in Stockholm County (collected 1998-2000), with linkage to the National Patient Register. The study base comprised participants aged 20-64 years (N = 10 345), followed-up until 2014. Cox and logistic regression analyses were conducted to test associations between self-reported cannabis use and risk of subsequent other illicit drug use (three-year follow-up) and drug use disorders (16-year follow-up).

FINDINGS

The odds ratio (OR) for other illicit drug use onset at three-year follow-up for lifetime cannabis users was 7.00 (4.47-10.35, 95% CI) and for recent cannabis users 34.41 (19.14-61.88, 95% CI). Adjusting for age and AUDIT score attenuated the association, for lifetime users: OR = 5.48 (3.69-8.13, 95% CI) and OR = 5.65 (3.80-8.41, 95% CI), and for recent users: OR = 18.32 (9.88-33.99, 95% CI) and OR = 20.88 (11.19-38.95, 95% CI). For cannabis users only, the hazard ratio (HR) for drug use disorders at 16-year follow-up was 0.89 (0.31-2.61, 95%CI). For cannabis and other illicit drug users, the corresponding HR was 7.27 (3.85-13.75, 95% CI).

CONCLUSIONS

There was no independent association between cannabis use and subsequent drug use disorders. The association with subsequent drug use disorders was rather explained by other illicit drug use, which cannabis users were at higher risk of at the three-year follow-up.

The Role of Life Events/Contextual Factors and Cannabis Use in Patterns of Other Drug Use Among Young Adult Cannabis Users in Los Angeles: A Qualitative Inquiry

This analysis examined the role of impactful life events/stressful contextual factors and cannabis use in the patterns of illicit drug use. It utilized semi-structured qualitative interviews with 40 young adult medical cannabis patients and 22 non-patient users collected in Los Angeles during 2014-2015. Three patterns of illicit drug use emerged based on participants' narratives: regular/problematic, recreational/occasional, and never users. Among regular/problematic users, a common theme was the lasting impact of traumatic life events or stressful contextual factors on transition to and away from problematic drug use, and using cannabis to cope with negative after effects of drug use. In contrast, most recreational/occasional and never users, who reported impactful life events or stressful contextual factors, used cannabis to cope with those experiences. Family history of addiction and acceptance of cannabis use within a family as protective factors against illicit drug use among some recreational/occasional and never users was an unexpected finding.

Opioid use disorder

Opioid use disorder (OUD) is a chronic relapsing disorder that, whilst initially driven by activation of brain reward neurocircuits, increasingly engages anti-reward neurocircuits that drive adverse emotional states and relapse. However, successful recovery is possible with appropriate treatment, although with a persisting propensity to relapse. The individual and public health burdens of OUD are immense; 26.8 million people were estimated to be living with OUD globally in 2016, with >100,000 opioid overdose deaths annually, including >47,000 in the USA in 2017. Well-conducted trials have demonstrated that long-term opioid agonist therapy with methadone and buprenorphine have great efficacy for OUD treatment and can save lives. New forms of the opioid receptor antagonist naltrexone are also being studied. Some frequently used approaches have less scientifically robust evidence but are nevertheless considered important, including community preventive strategies, harm reduction interventions to reduce adverse sequelae from ongoing use and mutual aid groups. Other commonly used approaches, such as detoxification alone, lack scientific evidence. Delivery of effective prevention and treatment responses is often complicated by coexisting comorbidities and inadequate support, as well as by conflicting public and political opinions. Science has a crucial role to play in informing public attitudes and developing fuller evidence to understand OUD and its associated harms, as well as in obtaining the evidence today that will improve the prevention and treatment interventions of tomorrow.

Revisiting the Association Between "Gateway Hypothesis" of Early Drug Use and Drug Use Progression: A Cohort Analysis of Peer Influences on Drug Use Progression Among a Population Cohort

Background and objective: Findings from observational studies indicate that early drug use is a strong predictor of further drug abuse. Because competing explanations abound in cross-sectional studies, causal interpretations from these investigations pose considerable challenge. We evaluated the relationship between early drug use and progression, while estimating modifying influences of adolescents' social contexts. Method: We applied a national longitudinal survey of 11,182 adolescents growing into adulthood over a 14-year period. The data provided a natural setting to evaluate the relationship between early drug use and drug use in three subsequent waves. We applied generalized estimating equation models to analyze these relationships. Results: Evidence showed over a relatively short period (approximately one year) early drug use was an independent predictor of illicit drugs in adolescence but not adulthood. The adjusted odds ratio for using substances in adulthood were marijuana (aOR, 1.33; 95% CI: 1.11-1.60), illicit drugs (aOR, 1.49; 95% CI: 1.04-2.12) and cocaine (aOR, 5.00; 95% CI: 2.75-9.10). Further, drug use was higher among older adolescence living in a neighborhood and reporting drug use as a big problem. In adulthood, neighborhood drug problems appear to have minimal influence on drug use escalation. Conclusion: The current findings call into question the causal interpretation of early drug use among adolescents as determinants of future drug escalation in adulthood. The overall impact of peer relationships on future drug escalation might depend on not only the extent of adolescent closeness to peers but also on continuity of friendship over time and other influencing social contexts.

Sexual orientation and gender identity disparities in substance use disorders during young adulthood in a United States longitudinal cohort

BACKGROUND

This study examined associations of sexual orientation and gender identity with prevalence of substance use disorders (SUDs) and co-occurring multiple SUDs in the past 12-months during young adulthood in a United States longitudinal cohort.

METHODS

Questionnaires self-administered in 2010 and 2015 assessed probable past 12-month nicotine dependence, alcohol abuse and dependence, and drug abuse and dependence among 12,428 participants of an ongoing cohort study when they were ages 20-35 years. Binary or multinomial logistic regressions using generalized estimating equations were used to estimate differences by sexual orientation and gender identity in the odds of SUDs and multiple SUDs, stratified by sex assigned at birth.

RESULTS

Compared with completely heterosexuals (CH), sexual minority (SM; i.e., mostly heterosexual, bisexual, lesbian/gay) participants were generally more likely to have a SUD, including multiple SUDs. Among participants assigned female at birth, adjusted odds ratios (AORs) for SUDs comparing SMs to CHs ranged from 1.61 to 6.97 (ps<.05); among participants assigned male at birth, AORs ranged from 1.30 to 3.08, and were statistically significant for 62% of the estimates. Apart from elevated alcohol dependence among gender minority participants assigned male at birth compared with cisgender males (AOR: 2.30; p < .05), gender identity was not associated with prevalence of SUDs.

CONCLUSIONS

Sexual and gender minority (SGM) young adults disproportionately evidence SUDs, as well as co-occurring multiple SUDs. Findings related to gender identity and bisexuals assigned male at birth should be interpreted with caution due to small sample sizes. SUD prevention and treatment efforts should focus on SGM young adults.

Adult substance use as a function of growth in peer use across adolescence and young adulthood in the context of ADHD: Findings from the MTA

Peer substance use strongly predicts adolescent and young adult substance use, but its role in ADHD-related risk for substance use, especially in adulthood, is unclear. In a sample with (n = 516) and without (n = 249) childhood ADHD from the Multimodal Treatment Study of ADHD, we compared associations between change over time in peer substance use and personal substance use (alcohol, cigarettes, marijuana, illicit drugs) from age 14-26 by ADHD status. Developmentally typical peer substance use trajectories across adolescence and young adulthood coincided with similar changes in personal use - but less so for those with ADHD histories. Concurrent associations between peer and personal use in adolescence and young adulthood were weaker for those with ADHD histories than without for commonly used substances (alcohol, marijuana). Prospectively, escalating peer use during adolescence forecasted adulthood declines for commonly used substances, yet persistently high substance use at age 25, regardless of ADHD history. In the reverse direction, growth in adolescent substance use predicted developmentally normative young adult declines in peer use - but for the ADHD group, adolescent heavy drinking predicted increases in young adult peer use. Findings suggest that individuals with ADHD may have difficulty emulating their peers' developmentally normative declines in substance use, highlighting the importance of social factors when treating young adults affected by ADHD and substance abuse.

The relative importance of perceived substance misuse use by different peers on smoking, alcohol and illicit drug use in adolescence

BACKGROUND

Substance use by young people is strongly associated with that of their peers. Little is known about the influence of different types of peers. We tested the relationship between perceived substance use by five types of peers and adolescents' use of illicit drugs, smoking, and alcohol consumption.

METHODS

We used data collected from 1285 students aged 12-13 as part of a pilot cluster randomized controlled trial (United Kingdom, 2014-2016). The exposures were the perceived use of illicit drugs, smoking and alcohol consumption by best friends, boy or girlfriends, brothers or sisters, friends outside of school and online. Outcomes were self-reported lifetime use of illicit drugs, smoking and alcohol consumption assessed 18-months later.

RESULTS

The lifetime prevalence of illicit drug use, smoking and alcohol consumption at the 18-month follow-up were 14.3%, 24.9% and 54.1%, respectively. In the fully adjusted models, perceived substance use by friends outside of school, brothers or sisters, and online had the most consistent associations with outcomes. Perceived use by friends online was associated with an increased risk of ever having used illicit drugs (odds ratio [OR] = 2.43, 95% confidence interval [CI] = 1.26, 4.69), smoking (OR = 1.61, 95% CI 0.96, 2.70) and alcohol consumption (OR = 2.98, 95% CI = 1.71, 5.18).

CONCLUSIONS

Perceived substance use by friends outside of school, brothers and sisters and online could be viable sources of peer influence. If these findings are replicated, a greater emphasis should be made in interventions to mitigate the influence of these peers.

An association between latent toxoplasmosis and substance abuse: an Egyptian Center Study

Infection of toxoplasma gondii (TG), an intracellular neurotropic parasitic protozoon, has been associated with various neuropsychiatric disorders. TG is usually diagnosed from serological sample in which a positive test for Anti-TG immunoglobulin G (IgG) indicates TG infection (toxoplasmosis). The research was conducted to test the hypothesis that TG infection may be associated with substance abuse. Anti-TG (IgG) was screened in 444 participants (350 abusers and 94 controls) who attended the Psychiatry Department of Mansoura University Hospitals. All participants were screened for different class of abused substances (tramadol, cannabis, opiates, barbiturates and benzodiazepines) using enzyme multiplied immunoassay technique and positive cases were confirmed using gas chromatography-mass spectroscopy (GC-MS). Substance users were also diagnosed according to DSM IV criteria. GC-MS assays revealed that 116 cases (33.1% of users) had documented use of more than one substance. Tramadol was the most common abused substance [86 cases (24.6%)]. About 56% of the participants were sero-positive for anti-TG IgG. Toxoplasmosis sero-positivity was significantly higher among substance abusers (P < 0.0001) irrespective of the class of substance used. There was a significant relationship between toxoplasma sero-positivity and occurrence of convulsions among tramadol users (P = 0.0007) and those relapsing (P < 0.0001) following short periods of abstinence. The data collected suggest that TG infection is significantly associated with the high incidence of substance use, irrespective of the drug class. These preliminary findings warrant further larger multicenter clinical studies to test the robustness of this association.

Program Capacity to Deliver Prevention Services to Children of Adult Clients Receiving Substance Use Disorder Treatment

Children whose parents have a history of substance use are at elevated risk of developing substance use disorders (SUDs) and related debilitating behaviors. Although specialty treatment programs are uniquely positioned to deliver prevention care to children of adult clients, these programs may have limited capacity to implement prevention and early intervention care services, particularly in racial and ethnic minority communities. We merged data from program surveys and client records collected in 2015 to examine the extent to which program capacity factors are associated with the odds of delivering prevention and early intervention services for children of adult clients attending outpatient SUD treatment in low-income minority communities in Los Angeles County, California. Our analytic sample consisted of 16,712 clients embedded in 82 programs. Our results show that 85% of these programs reported delivering prevention care services, while 71% of programs delivered early intervention services. Programs with organizational climates supporting change and those that served a high number of clients annually were more likely to implement both prevention and early intervention practices. Programs accepting Medicaid payments and serving clients whose primary drug was marijuana were more than three times as likely to implement prevention services. Overall, our findings suggest both program- and client-level characteristics are associated with delivering preventive care offered to children of adult clients receiving SUD treatment in communities of color. As Medicaid has become a major payor of SUD treatment services and marijuana use has been legalized in California, findings identify capacity factors to deliver public health prevention interventions in one of the nation's largest public SUD treatment systems.

Childhood language development and later alcohol use behaviors

BACKGROUND

Studies have shown a correlation between language abilities and alcohol use; however, results are inconsistent. A recent study using a discordant twin design showed an association between early child language development and later alcohol use behaviors; i.e., the twin with more advanced language abilities was more likely to try alcohol earlier in adolescence (Latvala et al., 2014). The authors suggested that this could result from better socialization of individuals with greater language abilities, which could lead to more opportunities for alcohol experimentation. The findings by Latvala et al. raise interesting questions, but the study has limitations, and replication is needed.

METHOD

We aimed to replicate and build upon these results utilizing 488 same sex twin pairs from the Colorado Longitudinal Twin Study, a longitudinal sample with quantitative measures of language abilities starting when the twins were 14 months old.

RESULTS

We found no significant correlations between a latent measure of child language abilities or measures of general cognitive ability at ages 14, 20, and 24 months and a latent alcohol use variable at ages 17 and 22 years.

CONCLUSION

Our results did not replicate the association between early language ability and later alcohol use reported by Latvala et al. Possible reasons for differing results across samples, including varying cultural norms as well as differences in educational attainment, peer influences, and novelty seeking, were discussed.

Sex Differences in the Association Between School Experiences and Marijuana Use Among African American Adolescents

This study examined whether past month marijuana use among African American adolescents differed based on school experiences and individual feelings toward school. A secondary analysis of the 2012 National Survey on Drug Use and Health was conducted to answer research questions. Results from the multivariable logistic regression analyses revealed that female students at highest risk for recent use included those who held negative feelings toward school (OR 2.723, CI 1.683, 4.406, p < .001), felt courses were not interesting (OR 2.695, CI 1.513, 4.798, p < .01), and received mostly C's/D's/ F's in the last semester (OR 2.520, CI 1.614, 6.711,p < .001). For males, results indicated that male students at highest risk included those who held negative feelings toward school (OR 2.364, CI 1.365, 4.094, p < .01), felt things learned in school would not be important later in life (OR 3.470, CI 1.951, 6.173, p < .001), and received mostly C's/ D's/F's in the last semester (OR 2.733, CI 1.734, 4.309, p < .001). In the final model, of those who felt that most or all students in their grade used marijuana, males were 3 ½ times (OR 3.418, CI 1.741, 6.711, p < .001) and females were 8 times (OR 8.288, CI 3.526, 19.480, p < .001) more likely to have recently used marijuana. Such findings can be used by prevention specialists and health educators to develop and implement marijuana prevention programs and interventions specifically tailored to African American adolescents. Recommendations for future research are included.

Nonmedical Prescription Opioid Use by Parents and Adolescents in the US

BACKGROUND

To date, intergenerational patterns of nonmedical prescription opioid (NMPO) use have not been examined. We investigate the association between parental and adolescent NMPO use in the United States.

METHODS

Data are from 35 000 parent-child dyads with an adolescent aged 12 to 17 years from the 2004-2012 nationally representative National Surveys on Drug Use and Health. Using multivariable logistic regression models, we estimated the association between self-reported parental and adolescent lifetime NMPO use, controlling for parental and adolescent use of other drugs, attitudes about drug use, parental and adolescent psychosocial risk factors, and sociodemographic characteristics.

RESULTS

Controlling for other factors, parental NMPO use was associated with adolescent NMPO use (adjusted odds ratio [aOR] 1.30; 95% confidence interval [CI] 1.09-1.56). Mothers' use had a stronger association with adolescent use than fathers' use (aOR 1.62 [95% CI 1.28-2.056] versus aOR 0.98 [95% CI 0.74-1.24]). Associations between parental and adolescent NMPO use did not differ by adolescent sex or race and/or ethnicity. Parental lifetime smoking, low monitoring, and parent-adolescent conflict were uniquely associated with adolescent NMPO use (aOR 1.19-1.24) as were adolescent smoking, marijuana use, depression, delinquency, and perceived schoolmates' drug use (aOR 1.25-1.71). Perceived risk of drug use and religiosity were associated with lower rates of adolescent NMPO use (aOR 0.77-0.93). Use among older adolescents was higher than among younger adolescents (aOR 1.27; 95% CI 1.21-1.34).

CONCLUSIONS

Parent-based interventions targeted at adolescent NMPO use should address parental NMPO use and smoking and promote positive parenting.

Child maltreatment and the development of substance use and disorder

Children who experience maltreatment are at well-documented risk for the development of problematic substance use and disorder in adolescence and beyond. This review applies a developmental psychopathology framework to discuss the complex multilevel probabilistic pathways from child maltreatment to substance use and substance use disorder (SUD). We begin with an overview of the myriad vulnerabilities associated with child maltreatment, including the development of substance use and SUD. Prominent pathways that may potentiate liability for SUD are discussed. Specifically, we highlight the robust empirical support for the prominent externalizing pathway of risk, and also discuss the state of the research regarding the internalizing pathway. Consistent with the developmental psychopathology perspective, we then review biological processes such as neuroendrocrine mechanisms, allostatic load, and neurobiological pathways that may underlie child maltreatment risk, as well as discuss broader contextual issues. Elucidating the processes underlying the development of substance use and disorder among children exposed to this form of early adversity is paramount for not only informing developmental theories, but also designing effective prevention and intervention programs. Thus, implications for preventive interventions are provided. Finally, critical next steps for research within the area of child maltreatment and the developmental psychopathology of substance use and SUD are proffered.

Stress, sensitive periods, and substance abuse

Research on the inter-relationship between drug abuse and social stress has primarily focused on the role of stress exposure during adulthood and more recently, adolescence. Adolescence is a time of heightened reward sensitivity, but it is also a time when earlier life experiences are expressed. Exposure to stress early in postnatal life is associated with an accelerated age of onset for drug use. Lifelong addiction is significantly greater if drug use is initiated during early adolescence. Understanding how developmental changes following stress exposure interact with sensitive periods to unfold over the course of maturation is integral to reducing their later impact on substance use. Arousal levels, gender/sex, inflammation, and the timing of stress exposure play a role in the vulnerability of these circuits. The current review focuses on how early postnatal stress impacts brain development during a sensitive period to increase externalizing and internalizing behaviors in adolescence that include social interactions (aggression; sexual activity), working memory impairment, and depression. How stress effects the developmental trajectories of brain circuits that are associated with addiction are discussed for both clinical and preclinical studies.

Neurocognitive Precursors of Substance Misuse Corresponding to Risk, Resistance, and Resilience Pathways: Implications for Prevention Science

Studies of substance misuse prevention generally focus on characteristics that typify risk, with the assumption that the prevalence of the problem will be optimally reduced by identifying, targeting, and reducing or eliminating risk factors. However, this risk-centered approach neglects variations in individual-level and environmental characteristics that portend differential pathways that are distinguishable by timing of substance use initiation (e.g., early versus delayed), the likelihood of use escalation versus eventual desistance, and enduring abstinence, despite exposure to significant risk factors. Considering the various underpinnings of these distinct substance use trajectories is critical to a more nuanced understanding of the effects, potency, and malleability of factors that are known to increase risk or confer protection. Here, we discuss three pathways relative to substance use patterns and predictors in the context of adversity, a well-known, highly significant influence on propensity for substance misuse. The first pathway is designated as "high risk" based on early onset of substance use, rapid escalation, and proneness to substance use disorders. Individuals who defy all odds and eventually exhibit adaptive developmental outcomes despite an initial maladaptive reaction to adversity, are referred to as "resilient." However, another categorization that has not been adequately characterized is "resistant." Resistant individuals include those who do not exhibit problematic substance use behaviors (e.g., early onset and escalation) and do not develop substance use disorders or other forms of psychopathology, despite significant exposure to factors that normally increase the propensity for such outcomes (e.g. trauma and/or adversity). In this paper, we apply this conceptualization of risk, resistance, and resilience for substance misuse to a more fine-grained analysis of substance use pathways and their corresponding patterns (e.g., non-use, initiation, escalation, desistance). The significance of the progression of neurocognitive functioning over the course of development is discussed as well as how this knowledge may be translated to make a science-based determination of intervention targets. This more encompassing theoretical model has direct implications for primary prevention and clinical approaches to disrupt risk pathways and to optimize long-term outcomes.

Comparison of age of first drink and age of first intoxication as predictors of substance use and mental health problems in adulthood

BACKGROUND

International public policy on age of first alcoholic drink (AFD) has emphasised the long-term benefits of delaying AFD. This study aimed to compare AFD to age of first intoxication (AFI) as predictors of substance use disorder and mental disorder outcomes in adulthood.

METHODS

Data were obtained from a longitudinal birth cohort in Christchurch, New Zealand. Participants were born in 1977. Analysis samples ranged from n = 1025 (age 18) to n = 962 (age 35). Measures of AFD and AFI were generated using parental- and self-report data collected from age 11. Outcomes at age 18-35 were alcohol quantity consumed, DSM-IV alcohol use disorder (AUD) and AUD symptoms, major depression, anxiety disorder, and nicotine, cannabis, and other illicit drug dependence. Covariate factors measured during childhood included family socioeconomic status, family functioning, parental alcohol-related attitudes/behaviours, and individual factors.

RESULTS

There was a significant unadjusted association between AFD and symptoms of AUD (p < .001) and nicotine dependence (p < .05) but not other outcomes. AFI was significantly (p < .05) associated with all outcomes. After adjustment for covariates, the association between AFD and outcomes was not statistically significant. Conversely, in adjusted models, statistically significant (p < .05) associations remained between AFI and all AUD and substance use disorder outcomes but not alcohol consumption or mental disorder outcomes.

CONCLUSIONS

AFI was a more robust predictor of adult substance use disorder outcomes than AFD. Public health and policy interventions aimed at prevention of long term harms from alcohol should therefore focus on AFI rather than AFD.

Adapting substance use brief interventions for adolescents: perspectives of adolescents living with adults in substance use disorder treatment

Background

Brief interventions (BIs) have shown potential to reduce both alcohol and drug use. Although BIs for adults have been studied extensively, little is known about how to adapt them to meet the needs and preferences of adolescents. This article examines adolescents' preferences to consider when adapting BIs for use with adolescents.

Methods

Eighteen adolescents (age 9-17 years) living in Los Angeles County with adults receiving substance use disorder treatment were interviewed and asked about their perspectives on how to adapt a BI originally developed for adults for use with adolescents. Questions focused on adolescents' preferences for who should deliver BIs, how BIs should be delivered, and what content they would want to be included in BIs. Interviews were recorded, transcribed, and coded using summative content analysis.

Results

Adolescents did not express any discernable opinions concerning who delivers BIs or what content they would want to be included, but they did share perspectives on how BIs should be delivered. Most adolescents did not endorse incorporating text messaging or social media into BIs. Instead they preferred having BIs delivered face-to-face or over the telephone. They reported that they did not want BIs to incorporate text messaging or social media due to concerns about trust, the quality of information they would receive, and challenges communicating in writing instead of speaking.

Conclusion

Although the study has limitations because of its small sample size, findings indicate that adolescents may not want text messaging or social media to be incorporated into BIs for substance use. These findings warrant further research and consideration, particularly as work to enhance BIs for adolescents continues.