Cannabis Use Disorder Predicted Shorter Treatment Retention in Young People With Opioid Addiction
Among adolescents and young adults with opioid use disorder, those with co-occurring cannabis use disorder stayed in treatment for shorter periods, while depression and PTSD were linked to longer retention.
Quick Facts
What This Study Found
Cannabis use disorder predicted shorter treatment retention (p=0.02), while depression (p=0.04), PTSD (p=0.002), and alcohol use disorder (p=0.04) were associated with longer retention. Cannabis use disorder and male sex predicted positive urine tests for THC, while medication for OUD was linked to lower THC positivity. The median retention time was 300 days.
Key Numbers
157 patients, median retention 300 days. CUD predicted shorter retention (p=0.02). Depression (p=0.04) and PTSD (p=0.002) predicted longer retention. Median proportion positive UDTs: 0.9 for MOUD (good adherence), 0.1 for illicit substances, 0.0 for THC. CUD (p=0.02) and male sex (p=0.04) predicted THC-positive urine tests.
How They Did This
Retrospective cohort study of 157 adolescents and young adults enrolled in a Substance Use Treatment and Recovery clinic from 2009 to 2022. Treatment retention and urine drug test results were analyzed using Kruskal-Wallis tests and regression models.
Why This Research Matters
Opioid addiction treatment in young people is already challenging, and this study suggests co-occurring cannabis use disorder adds another barrier to retention. Understanding which comorbidities help versus hinder treatment can guide clinical approaches.
The Bigger Picture
As cannabis becomes more available, its intersection with opioid addiction treatment in young people deserves attention. This study suggests that cannabis use disorder may compete with or undermine opioid treatment engagement in ways that depression and trauma do not.
What This Study Doesn't Tell Us
Retrospective single-center study. Small sample (157). Cannot determine causation. THC positivity may reflect legal medical use in some cases. The study period (2009-2022) spans significant changes in cannabis policy and availability.
Questions This Raises
- ?Would addressing cannabis use disorder directly improve opioid treatment retention?
- ?Does the type of cannabis use (medical vs recreational) matter for treatment outcomes?
- ?Should opioid treatment programs screen more aggressively for CUD?
Trust & Context
- Key Stat:
- Cannabis use disorder predicted shorter treatment retention (p=0.02) while depression and PTSD predicted longer stays
- Evidence Grade:
- Preliminary: retrospective single-center study with relatively small sample, limiting causal inference and generalizability.
- Study Age:
- 2025 study using 2009-2022 clinical data.
- Original Title:
- Impact of Co-Occurring Psychiatric Comorbidities and Substance Use Disorders on Outcomes in Adolescents and Young Adults with Opioid Use Disorder: A Retrospective Cohort Study.
- Published In:
- Pharmaceuticals (Basel, Switzerland), 18(5) (2025)
- Database ID:
- RTHC-06965
Evidence Hierarchy
Looks back at existing records to find patterns.
What do these levels mean? →Frequently Asked Questions
Why might cannabis use disorder shorten opioid treatment?
The study did not determine the mechanism, but possible explanations include competing substance use priorities, lower motivation for treatment, or different behavioral patterns among those with multiple substance use disorders.
Did medication-assisted treatment help reduce cannabis use?
Being on medication for opioid use disorder (MOUD) was linked to lower THC-positive urine tests (p=0.02), suggesting MOUD may have some protective effect against cannabis use.
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Cite This Study
https://rethinkthc.com/research/RTHC-06965APA
Liu, Ligang; McKnight, Erin R; Bonny, Andrea E; Tao, Heqing; Zhao, Pujing; Nahata, Milap C. (2025). Impact of Co-Occurring Psychiatric Comorbidities and Substance Use Disorders on Outcomes in Adolescents and Young Adults with Opioid Use Disorder: A Retrospective Cohort Study.. Pharmaceuticals (Basel, Switzerland), 18(5). https://doi.org/10.3390/ph18050609
MLA
Liu, Ligang, et al. "Impact of Co-Occurring Psychiatric Comorbidities and Substance Use Disorders on Outcomes in Adolescents and Young Adults with Opioid Use Disorder: A Retrospective Cohort Study.." Pharmaceuticals (Basel, 2025. https://doi.org/10.3390/ph18050609
RethinkTHC
RethinkTHC Research Database. "Impact of Co-Occurring Psychiatric Comorbidities and Substan..." RTHC-06965. Retrieved from https://rethinkthc.com/research/liu-2025-impact-of-cooccurring-psychiatric
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.