Cannabis Use Didn't Derail Intensive PTSD Treatment for Veterans
Veterans who used cannabis before or during intensive PTSD treatment programs showed similar symptom improvement to non-users — cannabis use didn't appear to undermine treatment effectiveness.
Quick Facts
What This Study Found
Across two samples of veterans undergoing Cognitive Processing Therapy-based intensive treatment programs (3-week program: N=488; 2-week program: N=253), researchers examined whether cannabis use frequency before or during treatment affected PTSD and depression outcomes.
Veterans in both programs reported low rates of cannabis use overall. The central finding was that cannabis use frequency — whether measured before treatment or concurrently — was not significantly associated with different trajectories of PTSD or depression symptom improvement over time.
Both cannabis-using and non-using veterans showed significant reductions in PTSD (measured by PCL-5) and depressive symptoms (measured by PHQ-9) from pre- to post-treatment. The treatment appeared to work regardless of cannabis use status.
This finding held across both the 3-week and 2-week program formats, providing replication across two independent samples with slightly different treatment intensities.
Key Numbers
Two samples: N=488 (3-week ITP) and N=253 (2-week ITP). Cannabis use frequency not significantly associated with PTSD or depression symptom change trajectories. Both users and non-users showed significant symptom improvement on PCL-5 and PHQ-9.
How They Did This
Observational study of two veteran samples in Cognitive Processing Therapy-based intensive treatment programs (N=488 for 3-week; N=253 for 2-week). Cannabis use frequency self-reported over past 2 weeks. PTSD measured by PCL-5, depression by PHQ-9, assessed before, during, and after treatment. Linear mixed-effects models analyzed cannabis use frequency effects on symptom trajectories.
Why This Research Matters
Some treatment programs exclude or discourage cannabis-using patients, and clinicians may worry that cannabis use undermines evidence-based PTSD therapy. This study provides reassurance that cannabis use at the levels observed didn't appear to interfere with intensive treatment — meaning cannabis-using veterans shouldn't necessarily be excluded from these programs.
The Bigger Picture
This study presents an interesting contrast with the abstinence study (RTHC-00274), which found that quitting cannabis produced larger PTSD improvements. The key difference: this study asked whether cannabis use undermines treatment (answer: no), while the abstinence study asked whether quitting cannabis enhances improvement (answer: possibly yes). Both can be true — cannabis may not prevent therapy from working, but quitting might allow it to work even better. The veteran harm reduction study (RTHC-00267) adds the patient perspective on why veterans continue using during treatment.
What This Study Doesn't Tell Us
Low overall rates of cannabis use in these samples may have limited statistical power to detect effects. Self-reported cannabis use likely underestimates actual use in a treatment setting. Observational design — cannabis-using and non-using veterans may differ in unmeasured ways. Intensive treatment programs are a specific context; results may not generalize to standard outpatient PTSD therapy.
Questions This Raises
- ?Would heavier cannabis use (not captured in these low-use samples) interfere with treatment more than light use?
- ?Could cannabis use actually enhance treatment engagement for some veterans by reducing avoidance?
- ?Is there a level of cannabis use above which treatment outcomes start to diverge?
Trust & Context
- Key Stat:
- Evidence Grade:
- Observational study with two independent replication samples — strengthened by consistency across both programs but limited by low cannabis use rates and observational design.
- Study Age:
- Published in 2026, addressing a practical clinical question relevant to the growing overlap between cannabis use and PTSD treatment seeking.
- Original Title:
- Impact of self-reported cannabis use on veterans' intensive PTSD treatment outcomes.
- Published In:
- Psychological trauma : theory, research, practice and policy, 18(3), 628-637 (2026) — Psychological Trauma is a reputable journal focusing on trauma research and its implications for practice.
- Authors:
- Schubert, Ryan A, Splaine, Cailan C, Montes, Mauricio M, Pridgen, Sarah A, Kaysen, Debra L, Held, Philip
- Database ID:
- RTHC-08609
Evidence Hierarchy
Watches what happens naturally without intervening.
What do these levels mean? →Read More on RethinkTHC
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- anxiety-response-technique-weed-withdrawal
- anxiety-toolkit-weed-withdrawal
- anxiety-worse-after-quitting-weed
- breathing-exercises-weed-withdrawal-anxiety
- cannabis-induced-anxiety
- does-weed-help-anxiety
- grounding-techniques-weed-withdrawal
- health-anxiety-weed-withdrawal
- manage-anxiety-without-weed
- quitting-weed-anxiety-disorder
- quitting-weed-anxiety-medication-ssri
- self-medicating-anxiety-with-weed
- therapy-quitting-weed-anxiety
- weed-and-anxiety
- weed-biphasic-effect-anxiety
- weed-generalized-anxiety-disorder
- weed-panic-attacks
- weed-paranoia
- weed-social-anxiety
- weed-tolerance-anxiety-stopped-working
- weed-withdrawal-anxiety
- weed-withdrawal-panic-attacks-night
- weed-withdrawal-work-anxiety
- withdrawal-anxiety-vs-real-anxiety
Cite This Study
https://rethinkthc.com/research/RTHC-08609APA
Schubert, Ryan A; Splaine, Cailan C; Montes, Mauricio M; Pridgen, Sarah A; Kaysen, Debra L; Held, Philip. (2026). Impact of self-reported cannabis use on veterans' intensive PTSD treatment outcomes.. Psychological trauma : theory, research, practice and policy, 18(3), 628-637. https://doi.org/10.1037/tra0001842
MLA
Schubert, Ryan A, et al. "Impact of self-reported cannabis use on veterans' intensive PTSD treatment outcomes.." Psychological trauma : theory, 2026. https://doi.org/10.1037/tra0001842
RethinkTHC
RethinkTHC Research Database. "Impact of self-reported cannabis use on veterans' intensive ..." RTHC-08609. Retrieved from https://rethinkthc.com/research/schubert-2026-impact-of-selfreported-cannabis
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.