Depression Risk
Study register · detail Prospektive Längsschnittstudie · Depression Risk · 2015

Associations of adolescent cannabis use with academic performance and mental health: A longitudinal study of upper middle class youth.

Mixed GRADE Low 113 citations
Samplen = 254 Pat.
Durationfour years of high school
Endpointschool grades and SAT score
Blindingn.a.
DesignProspektive Längsschnittstudie
Key finding

Persistent cannabis use was associated with lower school performance and more externalizing, but not internalizing, symptoms, with the effects no longer significant after controlling for alcohol and tobacco use.

Summary

Prospective cohort study (n=254) of upper-middle-class adolescents over 4 high school years; persistent cannabis use showed NO significant association with internalizing symptoms (β=0.04, p=0.53) — no increased depression risk after adjustment. However, externalizing symptoms (behavioral problems) were significantly increased (β=0.29, p<0.001). Effects became non-significant after controlling for concurrent alcohol and tobacco use.

P
PopulationAdolescents from a high-income community (upper middle class), n=254, age 14/15 to 17/18 years, longitudinal over four high school years
I
InterventionPersistent cannabis use (frequency assessed annually over 4 years)
O
OutcomePersistent cannabis use associated with lower GPA (β=-0.18, p=.006), lower SAT score (β=-0.13, p=.038) and stronger externalizing symptoms (β=0.29, p<.001) in grade 12; no significant association with internalizing symptoms (β=0.04, p=.53)
Confidence in the evidence
Low

The second of four GRADE levels, the effect estimate is of limited reliability.

Quality profile
Sample size
Blinding
Effect size Mixed
Citations / year
Authors
Meier MH, Hill ML, Small PJ, Luthar SS.
DOI 10.1016/j.drugalcdep.2015.09.010
Design: Prospektive Längsschnittstudie
Share
Abstract
<h4>Background</h4>There is a hypothesis that low socioeconomic status (SES) may explain the link between cannabis use and poorer academic performance and mental health. A key question, therefore, is whether adolescent cannabis use is associated with poorer academic performance and mental health in high SES communities where there is reduced potential for confounding.<h4>Methods</h4>Youth (n=254) from an upper middle class community were followed prospectively through the four years of high school (from age 14/15 to age 17/18). Past-year frequency of cannabis use was assessed annually. Official school records of academic performance and self-reported mental health symptoms (externalizing and internalizing symptoms) were assessed in grades 9 and 12.<h4>Results</h4>Persistent cannabis use across the four years of high school was associated with lower grade-point average (β=-0.18, p=.006), lower Scholastic Aptitude Test (SAT) score (β=-0.13, p=.038), and greater externalizing symptoms (β=0.29, p<.001) in 12th grade, but not with greater internalizing symptoms (β=0.04, p=.53). Moreover, persistent cannabis use was associated with lower grade-point average (β=-0.13, p=.014) and greater externalizing symptoms (β=0.24, p=.002) in 12th grade, even after controlling for 9th grade levels of these outcomes. Similar associations were observed for persistent alcohol and tobacco use. Effects for persistent cannabis use became non-significant after controlling for persistent alcohol and tobacco use, reflecting the difficulties of disentangling effects of cannabis from effects of alcohol and tobacco.<h4>Conclusions</h4>Low SES cannot fully explain associations between cannabis use and poorer academic performance and mental health.

The impediment to action advances action. — Marcus Aurelius