Childhood Family Conflict and Academic Struggles Predicted Lifelong Cannabis Use Trajectories
In a 30-year French cohort, 16% of cannabis users maintained persistent use from adolescence to their mid-40s, with early cannabis initiation, male sex, academic difficulties, and childhood family conflict as key predictors.
Quick Facts
What This Study Found
Three cannabis trajectories were identified: declining (69.9%), fluctuating (13.7%), and persistent (16.4%). Persistent use was predicted by male sex (OR 3.66), academic difficulties (OR 2.47), and early initiation of cannabis (OR 2.31) or combined tobacco+cannabis (OR 3.07). Fluctuating use was predicted by parental smoking (OR 2.18) and parental conflict/stress before age 17 (OR 1.93).
Key Numbers
622 participants, 14 measurements over 22 years (1999–2021). Declining: 69.9%. Fluctuating: 13.7%. Persistent: 16.4%. Male sex: OR 3.66 for persistent. Academic difficulties: OR 2.47. Early cannabis + tobacco initiation: OR 3.07. Parental conflict before 17: OR 1.93 for fluctuating.
How They Did This
Group-Based Trajectory Modelling of 622 participants from the French TEMPO cohort with 14 measurement points of cannabis use from 1999 to 2021 (ages 15–46). Multinomial logistic regression examined associations with early individual and family factors.
Why This Research Matters
Understanding that one in six cannabis users maintains persistent use into their mid-40s — and that this pattern is predictable from childhood factors — creates opportunities for early identification and targeted prevention before patterns become entrenched.
The Bigger Picture
Most people who use cannabis in adolescence will naturally decrease their use over time (70%). But the 16% with persistent use into middle age represent a group that may need sustained support, and their risk factors are identifiable in childhood — before cannabis use even begins.
What This Study Doesn't Tell Us
French cohort — patterns may differ in other countries, especially those with different legalization timelines. Self-reported use across 14 waves — some recall bias. Cannot account for all confounders. TEMPO cohort participants are children of a larger epidemiological study, potentially limiting representativeness.
Questions This Raises
- ?Would early interventions targeting academic support and family conflict reduce persistent cannabis use decades later?
- ?Do persistent users face different health outcomes than declining users?
- ?How does legalization affect these trajectories?
Trust & Context
- Key Stat:
- Evidence Grade:
- 30-year longitudinal cohort with 14 measurement points and sophisticated trajectory modeling, providing strong evidence for long-term use patterns.
- Study Age:
- Published 2025, data from 1999–2021.
- Original Title:
- Childhood events as factors in continued cannabis use in adulthood: a longitudinal study of a 30-year follow-up cohort.
- Published In:
- Journal of cannabis research, 7(1), 89 (2025)
- Authors:
- Wallez, Solène(2), Eren, Filiz(3), Kousignian, Isabelle, Avenin, Guillaume, Melchior, Maria, Mary-Krause, Murielle
- Database ID:
- RTHC-07905
Evidence Hierarchy
Frequently Asked Questions
Do most people who try cannabis as teens keep using it?
No — 70% of users in this study naturally decreased their use over time. About 14% had fluctuating patterns, and 16% maintained persistent use into their mid-40s. Most teen users will not become lifelong users.
Can you predict who will become a lifelong user?
This study identified key risk factors: being male, having academic difficulties, early cannabis initiation (especially combined with tobacco), and experiencing family conflict before age 17. These factors were significant predictors of persistent use trajectories.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-07905APA
Wallez, Solène; Eren, Filiz; Kousignian, Isabelle; Avenin, Guillaume; Melchior, Maria; Mary-Krause, Murielle. (2025). Childhood events as factors in continued cannabis use in adulthood: a longitudinal study of a 30-year follow-up cohort.. Journal of cannabis research, 7(1), 89. https://doi.org/10.1186/s42238-025-00345-0
MLA
Wallez, Solène, et al. "Childhood events as factors in continued cannabis use in adulthood: a longitudinal study of a 30-year follow-up cohort.." Journal of cannabis research, 2025. https://doi.org/10.1186/s42238-025-00345-0
RethinkTHC
RethinkTHC Research Database. "Childhood events as factors in continued cannabis use in adu..." RTHC-07905. Retrieved from https://rethinkthc.com/research/wallez-2025-childhood-events-as-factors
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.