Psychological Interventions Offer Minimal Impact in Schizophrenia With SUD
Key Clinical Summary
- Although substance use disorder (SUD) co-occurs in approximately 41.7% of individuals with schizophrenia, this population is often excluded from clinical trials.
- A large systematic review and meta-analysis found psychological and psychosocial interventions had minimal impact on overall symptoms and no significant effect on substance use reduction.
- Small benefits were observed only for nicotine use, underscoring the need for more effective, targeted treatments.
Patients with schizophrenia and co-occurring substance use disorder (SUD) represent a clinically complex and underserved population. In a new systematic review and meta-analysis published in JAMA Psychiatry, researchers found that psychological and psychosocial interventions had minimal impact on overall symptoms and no significant effect on substance use reduction in this patient population.
Study Findings
Investigators conducted a systematic review and random-effects pairwise meta-analysis of randomized clinical trials (RCTs) assessing psychological and psychosocial interventions in adults with schizophrenia and co-occurring SUD. There were no restrictions placed on the type of substance, including alcohol, cannabis, nicotine, or stimulants.
A total of 35 RCTs involving 4136 participants met inclusion criteria. Of these, 29 trials with 3831 participants contributed data to pairwise meta-analyses comparing interventions with control conditions. Among 3748 participants with reported sex, 25.4% were female, and the mean age was 37.2 years (range, 20.6–57.5 years).
The primary outcomes were overall psychiatric symptoms and substance use reduction measured by validated scales at posttreatment. Psychological and psychosocial interventions were associated with a very small reduction in overall symptoms compared with controls (standardized mean difference [SMD], –0.11; 95% CI, –0.27 to 0.05; 13 trials). Confidence in this estimate was rated as low using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, and the effect was mainly driven by studies focused on nicotine use.
No significant difference was observed between intervention and control groups for reduction in overall substance use (SMD, –0.01; 95% CI, –0.21 to 0.18; 8 trials), with moderate confidence in the estimate. When substances were analyzed separately, alcohol, cannabis, amphetamines, and other stimulants showed no meaningful effects, while nicotine use demonstrated a small benefit.
Clinical Implications
Although substance use disorder (SUD) co-occurs in approximately 41.7% of individuals with schizophrenia, this population is often excluded from clinical trials. The findings of this study highlight persistent gaps in evidence-based care despite the high prevalence and substantial healthcare burden associated with dual diagnoses.
For clinicians, this underscores the challenge of managing co-occurring schizophrenia and SUD using existing nonpharmacologic strategies alone. The lack of effect across most substance categories demonstrates the need for more tailored, integrated treatment approaches that address both psychotic symptoms and substance use behaviors.
Expert Commentary
“…Treating the clinically complex population of patients with schizophrenia and co-occurring SUD is undoubtedly challenging, with no psychotherapeutic options showing clear efficacy for overall symptoms and substance use reduction, except for nicotine use,” wrote Nurul Husna Salahuddin, MSc, Department of Psychiatry and Psychotherapy, TUM School of Medicine and Health, Technical University of Munich, Munich, Germany, and study coauthors.
“Clinicians should design and develop treatment plans for these patients by considering the integration of multiple interventions, including both pharmacological and psychosocial strategies addressing both psychotic symptoms and substance use reduction within combined inpatient and outpatient frameworks tailored to the needs of individuals with dual diagnoses,” they concluded.
