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Study breakdown

Cannabis use disorders linked to 38% higher medication non-compliance in schizophrenia patients

Cross SectionalStrong evidence
The takeaway

In over 1 million schizophrenia inpatients, those with cannabis use disorders had 38% higher odds of medication non-compliance after adjusting for demographics and comorbidities.

Psychiatrists, community mental health teams, and substance use treatment providers working with schizophrenia patients.

38% higher medication non-compliance with cannabis use disorder (1M+ patients)

What the researchers found

Among 1,030,949 schizophrenia inpatients (2010-2014), 26% were non-compliant with medications. Cannabis use disorder was independently associated with medication non-compliance (adjusted OR 1.38, 95% CI 1.268-1.489). CUD was disproportionately seen in young adults (18-35, 62.4%), males (80.5%), African Americans (54.1%), and low-income families (48.6%).

Why it matters

Medication adherence is the single most important factor in schizophrenia outcomes. Identifying cannabis use disorder as a strong independent predictor of non-compliance helps target intervention resources.

The numbers in context

1,030,949 inpatients; 26% medication non-compliance rate; unadjusted OR 1.49; adjusted OR 1.38 (CI 1.268-1.489); CUD patients: 62.4% young adults, 80.5% male, 54.1% African American.

How the study worked

Retrospective cross-sectional analysis of the Nationwide Inpatient Sample (NIS) with 1,030,949 schizophrenia inpatients aged 18-65 from 2010-2014, using ICD-9 codes for CUD and medication non-compliance with multivariable logistic regression.

What this study cannot tell us

Administrative database with ICD-9 coding limitations; cross-sectional (cannot determine temporal order); "non-compliance" is a recorded diagnosis, not a direct measure; cannot distinguish recreational from self-medicating cannabis use.

How to read the evidence

Strong: massive national database with over 1 million patients and appropriate multivariable adjustment.

When this study was published

Published 2020.

The bigger picture

This supports integrated treatment models addressing both cannabis use and psychosis simultaneously, rather than treating them separately. The demographic profile of CUD in schizophrenia also highlights health disparities worth examining.

Questions still open

  • Does treating cannabis use disorder in schizophrenia patients improve medication adherence? Are young men with schizophrenia using cannabis to manage symptoms or side effects?

Common questions

Does cannabis use affect medication compliance in schizophrenia?
Yes. In over 1 million schizophrenia inpatients, those with cannabis use disorders had 38% higher odds of medication non-compliance even after adjusting for age, sex, race, income, and other factors.
Who is most affected?
Cannabis use disorder in schizophrenia was most common in young adults aged 18-35 (62.4%), males (80.5%), African Americans (54.1%), and those in the lowest income quartile (48.6%).

Read the original research

Do cannabis use disorders increase medication non-compliance in schizophrenia?: United States Nationwide inpatient cross-sectional study.

Schizophrenia research, 224, 40-44

Citation

Patel, Rikinkumar S; Sreeram, Venkatesh; Vadukapuram, Ramu; Baweja, Raman. (2020). Do cannabis use disorders increase medication non-compliance in schizophrenia?: United States Nationwide inpatient cross-sectional study.. Schizophrenia research, 224, 40-44. https://doi.org/10.1016/j.schres.2020.11.002

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