Cannabis Use Disorder Was the Strongest Predictor of Relapse in Patients With Dual Diagnoses | Research

The takeaway

Among 611 substance use disorder inpatients, those with co-occurring psychiatric disorders had a 39.8% relapse rate at 3 months, with cannabis use disorder being the strongest predictor of relapse (OR=2.31), while being female and having higher intrinsic motivation were protective.

Treatment providers working with dual-diagnosis patients and people in recovery from cannabis use disorder

53.3% relapse rate for CUD

What the researchers found

Patients with co-occurring disorders (COD) had a 39.8% relapse rate vs 26.4% for those without. Among COD patients, cannabis use disorder had a 53.3% relapse rate and was the strongest predictor (OR=2.31, 95% CI: 1.34-4.00). Protective factors included older age, being female (OR=0.56), and higher intrinsic motivation (OR=0.58).

Why it matters

Cannabis use disorder is often perceived as less severe than other substance use disorders, but this study found it was the single strongest predictor of relapse among patients with dual diagnoses. This suggests cannabis-specific treatment components may be needed in dual-diagnosis programs.

The numbers in context

611 inpatients; 289 with COD; 39.8% vs 26.4% relapse rates; CUD relapse rate 53.3%; CUD OR=2.31; female OR=0.56; intrinsic motivation OR=0.58; 70% follow-up retention

How the study worked

Prospective cohort study of 611 SUD inpatients (289 with COD, 322 without). Demographics, motivation, mental distress, and diagnoses assessed at baseline. Relapse assessed at 3 months post-treatment (70% retention rate). Multivariate logistic regression identified predictors.

What this study cannot tell us

Three-month follow-up may be too short to capture longer-term outcomes. 30% loss to follow-up may introduce bias. Single-country setting (Norway) limits generalizability. Self-reported relapse may underestimate actual use.

How to read the evidence

Prospective cohort with good retention (70%) and multivariate analysis, but single site and short follow-up

When this study was published

2023 study

The bigger picture

Dual-diagnosis treatment programs may need to pay special attention to cannabis use disorder. The high relapse rate for CUD, combined with its association with psychiatric symptoms, suggests that addressing cannabis use should be a priority in these settings.

Questions still open

Why is cannabis use disorder such a strong relapse predictor? Does the accessibility and social acceptability of cannabis make abstinence harder? Would cannabis-specific treatment components reduce relapse in dual-diagnosis populations?

Common questions

Is cannabis use disorder hard to treat?

This study found cannabis use disorder had a 53.3% relapse rate at 3 months among patients with co-occurring psychiatric disorders, making it the strongest predictor of relapse among all substance types studied.

What protected against relapse?

Being female (OR=0.56), older age, and higher intrinsic motivation (OR=0.58) were associated with lower relapse risk. Intrinsic motivation refers to personal desire to change rather than external pressure.

Read the original research

Inpatients in substance use treatment with co-occurring psychiatric disorders: a prospective cohort study of characteristics and relapse predictors.

BMC psychiatry, 23(1), 152

View on PubMed ↗Publisher’s paper ↗

Citation

Andersson, Helle Wessel; Mosti, Mats P; Nordfjaern, Trond. (2023). Inpatients in substance use treatment with co-occurring psychiatric disorders: a prospective cohort study of characteristics and relapse predictors.. BMC psychiatry, 23(1), 152. https://doi.org/10.1186/s12888-023-04632-z