What topics does this cannabis study cover?

This study covers research on: Mental Health.

Where was this research published?

Published in Schizophrenia research on October 9, 2026.

Cross-sectional psychosis study finds cannabis links vary with tobacco use

Q: What did this research study find?

Among people with psychosis, **tobacco-only users had greater symptom burden and worse cognitive impairment** than several comparison substance-use groups.

Tobacco use moderates associations between cannabis use, psychiatric symptoms, and cognitive performance in psychosis spectrum disorders.

Schizophrenia research • October 9, 2026 • Highly Relevant

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AI Summary

This secondary analysis asked how tobacco and cannabis use, alone or together, relate to symptoms and cognitive performance in people with psychosis-spectrum disorders. It analyzed cross-sectional clinical and cognitive assessments from 884 participants in a multisite study; it was observational, not a trial, so it can identify associations but cannot show that either substance caused the outcomes.

The primary pattern was that tobacco-only users had greater symptom burden and worse cognitive impairment than several other substance-use groups. Cannabis-related findings varied with tobacco-use history: more adult cannabis use was associated with worse general psychopathology among current tobacco users, but fewer general symptoms among people who had never used tobacco. Greater cannabis use was also associated with better cognitive performance among current tobacco users, while it was not associated with working memory among past tobacco users. These mixed findings do not establish a benefit from cannabis. Because this is a cross-sectional secondary analysis and the abstract does not report effect sizes, it cannot establish causation or the clinical importance of the associations. This is an abstract-based summary.

💡 Key Findings

Among people with psychosis, tobacco-only users had greater symptom burden and worse cognitive impairment than several comparison substance-use groups.

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80%

Greater adult cannabis use was associated with worse general psychopathology in current tobacco users, but fewer general symptoms among those who had never used tobacco.

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80%

Greater adult cannabis use was associated with better cognitive performance among current tobacco users; among past tobacco users, it was not linked to working memory.

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80%

The cross-sectional analysis cannot establish that tobacco or cannabis caused differences in symptoms or cognition, and the abstract does not provide effect sizes to assess their magnitude.

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95%

📄 Original Abstract

Tobacco and cannabis use are highly prevalent among individuals with psychotic disorders. Tobacco use has been consistently linked to poorer clinical and cognitive outcomes, whereas findings regarding cannabis use remain mixed. The present study was a secondary analysis of cross-sectional data from the Bipolar-Schizophrenia Network on Intermediate Phenotypes 2, a large multi-site psychosis spectrum sample with cognitive and clinical assessments. The primary aim was to more precisely characterize how tobacco or cannabis use, co-use, and non-use differentially relate to clinical and cognitive function. The final sample included 884 individuals with psychotic disorders without diagnosis of substance abuse in the past 30 days or substance dependence in the past 3 months for any substance except tobacco. Among individuals with psychosis, tobacco-only users demonstrated greater symptom burden and worse cognitive impairment than several comparison psychosis substance groups. In contrast, cannabis use showed more nuanced associations. Greater adult cannabis use was tied to worse general psychopathology for current tobacco users but fewer general symptoms among those who never used tobacco. More adult cannabis use was linked to better cognitive performance for current tobacco users but was not linked to working memory among past tobacco users. These findings highlight tobacco use as a potential marker of greater disease severity and cognitive impairment among individuals with psychosis, while also demonstrating the importance of considering patterns of co-occurring use of substances.

Paper Type

📄 Research

Publication

Journal: Schizophrenia research
Published: October 9, 2026
PMID: 42854303
DOI: 10.1016/j.schres.2026.09.046

Authors (11)

Alyssa M Nelson Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN, USA.
Ashwin Srinivasan Department of Psychiatry, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
Brett Clementz Department of Psychology, University of Georgia, Athens, GA, USA.
Elliot Gershon Department of Psychiatry, University of Chicago, Chicago, IL, USA.
Matcheri Keshavan Department of Psychiatry, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
+6 more authors