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Study breakdown

Cariprazine Improves Both Schizophrenia Symptoms and Cannabis Dependence Over 6 Months

ObservationalLow evidence
The takeaway

In a 6-month observational study of 58 patients with both schizophrenia and cannabis use disorder, cariprazine treatment significantly improved psychotic symptoms, reduced cannabis use and dependence, and improved daily functioning.

psychiatrists, dual diagnosis treatment specialists, patients with co-occurring psychosis and cannabis use

What the researchers found

Cariprazine treatment over 6 months produced significant improvements in schizophrenia symptoms (PANSS change: -47.88 points, p<0.0001; CGI-SCH change: -8.26 points, p<0.0001). Cannabis use and dependence also decreased (CAST change: -7.0 points, p<0.0001; SDS change: -7.88 points, p<0.0001). Functioning improved (SDI change: -9.48 points, p<0.0001).

Why it matters

Patients with both schizophrenia and cannabis use disorder are common but poorly served by treatments that address only one condition. Finding a single medication that may improve both is clinically valuable.

The numbers in context

58 patients. 6-month follow-up. PANSS: -47.88 points (p<0.0001). CGI-SCH: -8.26 points (p<0.0001). CAST: -7.0 points (p<0.0001). SDS: -7.88 points (p<0.0001). SDI: -9.48 points (p<0.0001).

How the study worked

6-month observational study of 58 patients diagnosed with both schizophrenia and cannabis use disorder, treated with cariprazine in a real-world clinical setting. Multiple validated outcome measures for psychosis, cannabis use, dependence, and functioning.

What this study cannot tell us

No control group or randomization. Small sample (n=58). Observational design cannot establish causation. Real-world setting with potential selection bias. Improvement could reflect regression to the mean or natural course.

How to read the evidence

Significant improvements on all measures, but uncontrolled observational design with only 58 patients limits causal conclusions.

When this study was published

2025 publication.

The bigger picture

Dual diagnosis of schizophrenia and substance use is extremely common but rarely treated as a unified condition. Cariprazine, a partial dopamine agonist, may have unique properties that address both the psychotic and addictive components.

Questions still open

  • Would a randomized controlled trial confirm these effects?
  • What properties of cariprazine specifically reduce cannabis use?

Common questions

Can one medication treat both schizophrenia and cannabis addiction?
This observational study found cariprazine improved both schizophrenia symptoms and cannabis dependence over 6 months in 58 patients. However, without a control group, it is unclear if cariprazine is uniquely effective or if other antipsychotics would show similar results.
Does treating psychosis help reduce cannabis use?
In this study, patients receiving cariprazine for schizophrenia also showed significant reductions in cannabis use and dependence scores. This suggests that effective psychosis treatment may help address co-occurring substance use, though the study design cannot prove causation.

Read the original research

Cariprazine as a maintenance treatment in dual schizophrenia: a 6-month observational study in patients with schizophrenia and cannabis use disorder.

International clinical psychopharmacology, 40(3), 167-175

Citation

Szerman, Nestor; Vega, Pablo; Roncero, Carlos; Peris, Lola; Grau-López, Lara; Basurte-Villamor, Ignacio. (2025). Cariprazine as a maintenance treatment in dual schizophrenia: a 6-month observational study in patients with schizophrenia and cannabis use disorder.. International clinical psychopharmacology, 40(3), 167-175. https://doi.org/10.1097/YIC.0000000000000568

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