Study warns of strong link between cannabis use and adverse psychosocial events in adolescents, regardless of disorder classification

In a recent article published in the JAMA Network Open, researchers described the findings of their cross-sectional study conducted among the adolescent population of the United States of America (USA) to assess whether non-disordered cannabis use (NDCU) resulted in any adverse psychosocial events.

Study: Nondisordered Cannabis Use Among US Adolescents. Image Credit: snob / Shutterstock

Background

In the USA, young adults do not view cannabis use as hazardous. Accordingly, in the last decade, cannabis use among US adolescents aged >12 years surged from 11.6% to 17.9%, while the perceived risk of harm by weekly cannabis use declined by about 50%. In the future, such decreased negative perceptions about cannabis use would further increase its use among US adolescents. Moderating federal criminal justice policies in the US which have decriminalized marijuana possession could favor already increasing cannabis use trends among US adolescents.

However, clinicians recognize that cannabis use disorder (CUD) increases the risk of adverse mental health outcomes, e.g., depression and suicidal behaviors in adolescents. In addition, it hampers their cognitive and executive functioning, which affects the brain’s working memory, attentiveness, problem-solving, and decision-making abilities. Some longitudinal epidemiologic studies have shown that cannabis exposure increases the risk of psychosis diagnoses among adolescents by four-fold. Moreover, cannabis use dampens their academic performance and triggers delinquent behavior.

Yet, there is a shortage of studies differentiating between the risks posed by disordered cannabis use, CUD, and NDCU vs. non-use among youth cannabis users for adverse psychological events and the comparative strength of these associations.

Non-users denied cannabis use ever or at least in the past year. The researchers used the Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) (DSM-5) criteria to define CUD. So, youth endorsing recent cannabis use but not meeting the DSM-5 criteria or diagnostic threshold set by DSM-5 were considered NDCU cases. In other words, those having NDCU-endorsed cannabis use within the past 30 days or up to a year.

About the study

In the present study, researchers derived a nationally representative sample using National Survey on Drug Use and Health (NSDUH) data captured between 2015 and 2019, which comprised adolescent participants aged 12 to 17 years. Next, they divided all adolescent participants into non-use, CUD, and NDCU groups, to assess the comparative associations across several adverse psychosocial events between January and May 2022 based on the hypothesis that there could be an association between NDCU and adverse psychosocial events but to a lesser extent than that of CUD.

Additionally, the researchers evaluated sociodemographic factors, such as gender, race/ethnicity, education level, community, and total family income of all participants, plus information on their substance use disorders and depression.

The authors selected nine adverse psychosocial events for this analysis, as follows:

i) major depressive episode (MDE);

ii) slowed thinking;

iii) suicidal ideation (SI),i.e., thoughts of ending life;

iv) facing difficulty in concentrating;

v) truancy, i.e., skipping school for >1 day in the past month;

vi) being arrested for involvement in illegal activities,

vii) involved in fights;

viii) physical aggression, i.e., attack with intent to harm; and

ix) low-grade point average (GPA), i.e., C+ or below (i.e., <80%).

Finally, the team used logistic regression to compute unadjusted odds ratios (ORs) for NDCU and CUD use groups, using the non-use group as the control group and repeating the process for each adverse psychosocial event. Nonoverlapping 95% confidence intervals (CIs) indicated statistical differences in the strength of association with adverse events between NDCU and CUD groups, where a two-tailed p< .05 indicated a significant difference across groups.

Results

Within a nationally representative sample of US adolescents, NDCU was nearly four times more prevalent than CUD. Moreover, the authors noted a significant correlation between adolescent NDCU to all nine adverse psychosocial correlates examined in this study. Further, the magnitudes of correlations between adolescent NDCU and CUD and all adverse psychosocial events except MDE varied substantially. Yet, the majority of adolescents with NDCU endorsed nearly 25% of the minimum DSM-5 criteria.

The authors also observed higher odds of MDE and SI among adolescents who engaged in cannabis use. Strikingly, on measures of MDE, adolescents with NDCU and CUD did not vary markedly. Past studies have also shown depression and suicidality as markers of poor adolescent mental health, increasing the likelihood of adopting harmful substance use in adolescence.

Young adults succumb to substance use to improve mood symptoms associated with depression; however, its ongoing use does the reverse. In the future, longitudinal studies should examine the association between NDCU, a clinically relevant risk marker of major depression & suicidality, accounting for the public perspective that cannabis alleviates depressive symptoms.

Furthermore, the authors noted that adolescents in NDCU and CUD groups were nearly two-three times more prone to develop cognitive deficits and worsening executive functions than non-users. Few previous studies have highlighted that after abstaining from cannabis use beyond 30 days, cognitive deficits persist, which, in some cases, could lead to reduced hippocampal volume by midlife. Future work could examine the effect of cannabis abstinence on cognition among adults of varying age groups.

Another remarkable observation was that compared to non-users, adolescent cannabis users were up to 4.5 and 3.5 times more likely to skip school and report a low GPA, indicating poor academic performance, respectively.

Conclusions

Overall, the current study could not establish a cause-and-effect relationship between adolescent cannabis use in the NDCU & CUD groups and adverse socio-psycho outcomes but highlighted somewhat robust associations between the two. Longitudinal research using repeated measures on prospective data is, thus, warranted to uncover the reasons underlying these observations. The stepwise severity gradient for the odds of socio-psycho relationships among non-users, NDCU, and CUD groups also applied to their prevalence across all degrees of cannabis use.

The number of US adolescents with NDCU is around 2.5 million, and NDCU is more frequent than CUD, yet, a vast majority of the affected US adolescent population remains undiagnosed. It is a worrisome situation considering that they suffer from adverse effects meeting the criteria for pathological use.

Thus, there is an urgent need to improve the current diagnostic criteria and make it developmentally sensitive. Since the risk among individuals with NDCU vs. CUD did not vary substantially, associations between NDCU and adverse psychosocial events have implications in clinical practice. Clinicians should proactively screen, examine, and treat adolescent cannabis users as cannabis use surges equally for medicinal and recreational reasons.