Increases in cannabis use among young people has heightened concern about the potential interactive health effects of cannabis with other drugs. We examined the longitudinal association between concurrent and simultaneous (SAM) co-use of alcohol and cannabis in young adulthood on mental health symptoms, substance use behaviors, and substance-related harms two years later. Data were drawn from Time 5 (T5; n = 464; 46% male) and 6 (T6; n = 478; 45% male) of the Victoria Healthy Youth Survey. At T5, 42% of participants used alcohol-only, 13% used concurrently, 41% used SAM, 1% were cannabis only users, and 3% abstained from cannabis and alcohol. Boys were more likely to use SAM. Higher T5 SAM use frequency was associated with heavier use of substances, more substance-related harms, and symptoms of psychosis and externalizing problems at T6. T5 Concurrent use was associated with conduct symptoms, illicit drug use, and alcohol use disorders at T6 relative to alcohol-only use. Cannabis is commonly used with alcohol and the findings suggest that any co-use (concurrent or simultaneous) may be problematic in young adulthood. Public health messages need to explicitly inform consumers about the possible consequences of using both alcohol and marijuana and the addictive pharmacological impact of using them together.

No abstract

Early detection of risks for substance use disorders is essential to lifelong health and well-being for some youth. Very early-onset use is proposed as an indicator of risk for substance use disorders, but risk and protective factors related to early-onset use have not been identified. The current study compared risk and protective factors that distinguish early- and late-onset cannabis users from abstainers using data collected from a large community sample. The study also examined onset-group differences in participants’ reports of substance use disorder symptoms a decade later. Heavy episodic drinking (early-onset: OR = 7.29 CI = [1.60, 33.19]) and engagement with peers involved in deviant behaviors (early-onset: OR = 2.50 CI = [1.50, 4.13]) are risk factors for early-onset cannabis use. Protective factors, including parent monitoring (early-onset: OR = 0.73 CI = [0.58, 0.93]), engagement with peers involved in positive behaviors (early-onset: OR = 0.54 CI = [0.39, 0.76]), school engagement (early-onset: OR = 0.83 CI = [0.72, 0.96]), and academic grades (early-onset: OR = 0.37 CI = [0.21, 0.65]) also predicted early versus later onset-group differences. Early age of onset may be distinctly related to risk and protective factors previously associated with risks for substance use in all adolescents.

Purpose:We examined how heterogeneity in the patterns of adolescent experiences of different types and severity of peer victimization is associated with concurrent and longitudinal mental health, substance use, and physical health.Method: Data come from a randomly recruited communitybased sample of youth (T1 ages 12-18; N = 662; 52% female) followed biennially across 10 years (T6 ages 22-29; n = 478; 55% female). Results: Using latent class analysis, we identified four classes of adolescent peer victimization: Low victimization (63%), Physical victimization only (15%), Relational victimization only (17%), and Poly-victimization (6%). Youth in the Poly-victimization class reported the most detrimental health consequences in adolescence (e.g., internalizing and externalizing symptoms, illicit drug use, physical symptoms, poor physical self-concept, physical activity) and in young adulthood (e.g., depressive symptoms, sleep problems). Youth in the Relational and Physical victimization classes also reported health problems, some of which persisted into young adulthood. Youth in the Low victimization class reported the fewest health concerns.Conclusions: Findings add to our understanding of how different types of adolescent victimization are related to the hypothalamic-pituitary-adrenal axis (HPA; i.e., the body's stress response system), as well as blunted cortisol release also found in children and adolescents who experience other forms of stress or trauma (see Vaillancourt et al., 2013 for reviews). However, it is not known whether or how adolescent victimization experiences set the stage for continued health problems in young adulthood. The health effects (concurrent and across time) of different experiences of victimization (i.e., based on type and severity) are also not known. In this study, we add to the understanding of how different patterns of peer victimization affect mental health, substance use, and physical health in adolescence (ages 12-18) and 10 years later in young adulthood (ages 22-29).

No abstract