Clinical Summary
Clinical Summary: The Effects of Extended Cannabis Abstinence in Comorbid Posttraumatic Stress Disorder and Cannabis Use Disorder
Many patients with PTSD use cannabis to manage distress, sleep problems, and hyperarousal, yet clinicians have limited prospective data on whether stopping cannabis helps or worsens symptoms in those with comorbid cannabis use disorder. This study addresses that real-world question by tracking PTSD symptoms over 12 weeks of biochemically verified abstinence versus nonabstinence.
Design
Participants were asked to discontinue cannabis use for 12 weeks.
N
21 participants with complete data for analysis
Population
Participants with PTSD and co-occurring CUD, aged 18–65 years
Duration
12 weeks
Key Findings
- Among the 21 participants who completed all 12 study visits, 11 (52.4%) achieved 12 weeks of biochemically verified cannabis abstinence.
- PTSD symptom severity improved more with abstinence: CAPS-5 total scores decreased from 36.2 at baseline (95% CI: 29.72 to 42.62) to 10.5 at week 12 (95% CI: 4.09 to 16.98) in abstinent participants versus 34.6 (95% CI: 28.51 to 40.67) to 21.8 (95% CI: 15.11 to 28.45) in nonabstinent participants; time×group interaction β=-12.83, 95% CI: -19.98 to -5.67, SE =3.65, P =.001.
- Total PTSD symptom count also fell more with abstinence, from 14.3 at baseline (95% CI: 11.73 to 16.92) to 4.1 at week 12 (95% CI: 1.55 to 6.74), compared with 13.5 (95% CI: 11.05 to 15.95) to 8.9 (95% CI: 6.17 to 11.66) in nonabstainers; time × group interaction β = -5.59, 95% CI: -8.79 to -2.40, SE = 1.63, P = .001.
- Abstinence-related improvement was significant for PTSD symptom severity in avoidance and hyperarousal clusters: Cluster C β=-2.34, 95% CI: -3.88 to -0.80, SE =0.79, P=.0043 and Cluster E β=-5.57, 95% CI: -8.74 to -2.41, SE=1.61, P=.001.
- For PTSD symptom counts, significant abstinence-related interactions were observed in Cluster C (β=-0.88, 95% CI: -1.58 to -0.17, SE =0.36, P=.018), Cluster D (β=-2.33, 95% CI: -4.39 to -0.28, SE =1.05, P=.03), and Cluster E (β=-2.51, 95% CI: -3.75 to -1.26, SE=0.64, P<.001), while Cluster B was not significant (β=-0.78, 95% CI: -2.02 to 0.47, SE =0.64, P=.23).
Clinical Bottom Line
In patients with comorbid PTSD and cannabis use disorder, 12 weeks of biochemically verified cannabis abstinence was associated with larger reductions in PTSD severity and symptom burden than nonabstinence. For patients who report using cannabis to self-manage PTSD, abstinence belongs in the treatment discussion rather than assuming cannabis is therapeutic.
Practice Implications
- Assess cannabis use routinely in PTSD patients, especially when symptoms remain severe, because continued use in this comorbid PTSD/CUD sample tracked with less improvement over 12 weeks.
- When counseling patients who believe cannabis helps PTSD, discuss that abstinent participants improved from CAPS-5 total scores of 36.2 to 10.5, compared with 34.6 to 21.8 in nonabstinent participants.
- Target conversations to symptoms patients commonly self-medicate with cannabis, since abstinence-related differences were strongest in avoidance and hyperarousal domains (Cluster C and Cluster E severity interactions).
- If pursuing cessation, note that this study used weekly visits, urinalysis, brief 20-minute therapy sessions, and abstinence-contingent payments of $200, $300, and $400 at weeks 4, 8, and 12; structured support may be important for success.
