Large US Study Found Cannabis Linked to Substance Use Disorders but Not Mood or Anxiety Disorders
A nationally representative study of over 34,000 US adults found that cannabis use was associated with a 6.2-fold increased risk of developing any substance use disorder three years later, but was not associated with mood or anxiety disorders.
Quick Facts
What This Study Found
Researchers followed a nationally representative sample of over 34,000 US adults over three years to examine whether cannabis use predicted the development of psychiatric disorders.
After adjusting for a comprehensive set of confounders (demographics, family history, childhood adversity, prior psychiatric disorders, and more), cannabis use was strongly associated with subsequent substance use disorders: 6.2x for any substance use disorder, 9.5x for cannabis use disorder, 2.7x for alcohol use disorder, 2.6x for other drug use disorder, and 1.7x for nicotine dependence.
However, cannabis use was not significantly associated with developing any mood disorder (OR 1.1) or any anxiety disorder (OR 0.9). These patterns held across multiple analytical approaches including propensity score matching.
Key Numbers
34,653 respondents. 1,279 reported cannabis use at wave 1. Odds ratios for subsequent disorders: any substance use disorder 6.2, cannabis use disorder 9.5, alcohol use disorder 2.7, other drug use disorder 2.6, nicotine dependence 1.7. Any mood disorder 1.1 (not significant). Any anxiety disorder 0.9 (not significant).
How They Did This
Data came from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), with interviews at wave 1 (2001-2002) and wave 2 (2004-2005). The analysis included 34,653 respondents. Psychiatric disorders were assessed with structured diagnostic interviews. Multiple regression and propensity score matching were used, controlling for demographics, family history, childhood adversity, self-esteem, social deviance, recent trauma, and prior psychiatric conditions.
Why This Research Matters
This is one of the largest prospective studies to examine cannabis and psychiatric risk, and its pattern of results is notable: strong associations with substance use disorders but not with mood or anxiety disorders. This nuances the debate about cannabis and mental health by distinguishing which psychiatric outcomes are and are not associated with use.
The Bigger Picture
This study contributes to an important distinction in cannabis research: the association with substance use disorders appears robust and substantial, while the associations with mood and anxiety disorders appear weaker than often assumed. This has implications for how cannabis risk is communicated to the public.
What This Study Doesn't Tell Us
Despite the large sample and prospective design, the study cannot prove causation. People who use cannabis may differ from non-users in ways not captured by the confounders measured. The three-year follow-up may be too short to detect slower-developing conditions. Cannabis potency and use patterns have changed since 2001-2005.
Questions This Raises
- ?Why is cannabis strongly associated with substance use disorders but not mood or anxiety disorders?
- ?Would longer follow-up or assessment of cannabis use frequency change the pattern of results?
Trust & Context
- Key Stat:
- 6.2x risk of substance use disorders; no significant link to mood or anxiety disorders
- Evidence Grade:
- This is a large, nationally representative prospective cohort study with robust confounding control and multiple analytical approaches, providing strong evidence on the pattern of psychiatric associations.
- Study Age:
- Published in 2016, using 2001-2005 data. Cannabis potency and use patterns have changed, which may affect the relevance of specific risk estimates.
- Original Title:
- Cannabis Use and Risk of Psychiatric Disorders: Prospective Evidence From a US National Longitudinal Study.
- Published In:
- JAMA psychiatry, 73(4), 388-95 (2016)
- Authors:
- Blanco, Carlos(5), Hasin, Deborah S(31), Wall, Melanie M(16), Flórez-Salamanca, Ludwing, Hoertel, Nicolas, Wang, Shuai, Kerridge, Bradley T, Olfson, Mark
- Database ID:
- RTHC-01106
Evidence Hierarchy
Follows a group of people over time to track how outcomes develop.
What do these levels mean? →Frequently Asked Questions
Does cannabis cause other addictions?
The study found a strong association between cannabis use and later development of substance use disorders, but it cannot prove causation. Shared risk factors, genetic predisposition, or the social context of cannabis use could contribute to this association independently of a direct causal effect.
Why was there no link to depression or anxiety?
After controlling for prior psychiatric conditions and many other confounders, cannabis use did not predict new mood or anxiety disorders. This suggests that previously reported links between cannabis and these conditions may be partly explained by confounding factors rather than a direct effect of cannabis.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-01106APA
Blanco, Carlos; Hasin, Deborah S; Wall, Melanie M; Flórez-Salamanca, Ludwing; Hoertel, Nicolas; Wang, Shuai; Kerridge, Bradley T; Olfson, Mark. (2016). Cannabis Use and Risk of Psychiatric Disorders: Prospective Evidence From a US National Longitudinal Study.. JAMA psychiatry, 73(4), 388-95. https://doi.org/10.1001/jamapsychiatry.2015.3229
MLA
Blanco, Carlos, et al. "Cannabis Use and Risk of Psychiatric Disorders: Prospective Evidence From a US National Longitudinal Study.." JAMA psychiatry, 2016. https://doi.org/10.1001/jamapsychiatry.2015.3229
RethinkTHC
RethinkTHC Research Database. "Cannabis Use and Risk of Psychiatric Disorders: Prospective ..." RTHC-01106. Retrieved from https://rethinkthc.com/research/blanco-2016-cannabis-use-and-risk
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.