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Veterans With PTSD Who Quit Cannabis Saw Major Symptom Improvement

RTHC-085862026Rodas, Justyne D; Sorkhou, Maryam; Kloiber, Stefan; George, Tony P; Hassan, Ahmed N
Pilot StudyPreliminary evidence
The takeaway

Veterans with co-occurring PTSD and cannabis use disorder who achieved 12 weeks of abstinence saw their PTSD symptom scores drop from 36 to 10 — significantly more than those who continued using.

Veterans using cannabis for PTSD, VA clinicians treating co-occurring PTSD and CUD, PTSD researchers evaluating cannabis as treatment vs. complicating factor.

What the researchers found

In this open-label pilot study, 21 veterans with both PTSD and cannabis use disorder attempted 12 weeks of cannabis abstinence with contingency reinforcement (progressive payments for confirmed abstinence at weeks 4, 8, and 12).

Eleven participants achieved sustained abstinence; ten did not. The results were striking: abstainers' PTSD symptom scores (measured by the clinician-administered CAPS-5, the gold standard for PTSD assessment) dropped from 36.2 to 10.5 — a reduction of over 70%. Non-abstainers also improved, from 34.6 to 21.8, but significantly less.

The improvement was not uniform across PTSD symptom clusters. Avoidance, negative mood and cognition, and hyperarousal showed the greatest differential improvement in abstainers compared to non-abstainers. Re-experiencing symptoms improved across both groups regardless of abstinence status.

These findings challenge the common belief that cannabis helps manage PTSD. While many veterans use cannabis for trauma symptoms, this study suggests that sustained abstinence may actually produce larger symptom reductions than continued use.

Why it matters

PTSD is one of the most commonly cited reasons veterans use cannabis, and many advocate for medical cannabis as a PTSD treatment. This study provides the first prospective evidence that quitting cannabis — not starting it — may be what actually reduces PTSD symptoms. The magnitude of improvement (70% reduction in CAPS-5 scores) is clinically remarkable, even considering the small sample.

The numbers in context

N=21 veterans. 11 achieved abstinence, 10 did not. Abstainers: CAPS-5 scores 36.2 → 10.5 (71% reduction). Non-abstainers: 34.6 → 21.8 (37% reduction). Difference between groups: p=0.001. Greatest differential improvement in avoidance, negative cognition, and hyperarousal clusters.

How the study worked

Open-label pilot study, N=21 veterans with comorbid PTSD and CUD. Progressive contingency reinforcement payments for abstinence confirmed at weeks 4, 8, and 12. Abstinence defined as THC-COOH ≤50 ng/mL with no self-reported use. PTSD assessed via CAPS-5 (total severity, symptom count, cluster scores). Data collected January 2022 to April 2025.

Who was studied

N=21 adults aged 18-65 with comorbid PTSD and cannabis use disorder, US study.

What this study cannot tell us

Very small sample (N=21) in an open-label design without randomization. Self-selection bias: veterans who achieved abstinence may differ from those who didn't in motivation, severity, or other factors. Contingency payments may have influenced adherence rather than reflecting real-world conditions. No long-term follow-up — whether symptom improvement persists is unknown. The study cannot determine whether abstinence caused the improvement or whether both reflect a shared underlying factor.

How to read the evidence

Small open-label pilot study — the magnitude of the finding is provocative but the lack of randomization and small sample mean these results need replication before changing clinical practice.

When this study was published

Published in 2026 with data collected through April 2025, providing timely evidence in an active debate about cannabis and PTSD treatment.

The bigger picture

This directly challenges the narrative supporting cannabis for PTSD. The veteran harm reduction study (RTHC-00267) documented veterans using cannabis to manage trauma symptoms, and the intensive PTSD treatment study (RTHC-00276) examined cannabis use during evidence-based therapy. This abstinence study adds a critical counter-perspective: cannabis may be masking symptoms rather than treating them, and removal of cannabis may allow underlying PTSD treatments to work more effectively.

Replication

Not stated in abstract.

Funding

Not reported in abstract.

Conflicts of interest

Not reported in abstract.

Questions still open

  • Would a larger randomized trial replicate these findings? Does the PTSD improvement persist after contingency payments stop? Is there a subset of PTSD patients for whom cannabis genuinely helps, or does the abstinence benefit apply broadly?

Read the original research

The Effects of Extended Cannabis Abstinence in Comorbid Posttraumatic Stress Disorder and Cannabis Use Disorder.

The Journal of clinical psychiatry, 87(1)

The Journal of Clinical Psychiatry is a reputable journal focusing on psychiatric research.

View on PubMed ↗Publisher’s paper ↗

Citation

Rodas, Justyne D; Sorkhou, Maryam; Kloiber, Stefan; George, Tony P; Hassan, Ahmed N. (2026). The Effects of Extended Cannabis Abstinence in Comorbid Posttraumatic Stress Disorder and Cannabis Use Disorder.. The Journal of clinical psychiatry, 87(1). https://doi.org/10.4088/JCP.25m16099

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