In first-episode psychosis, cigarette smoking was linked to worse cognition and function even after accounting for cannabis use
Among 140 patients with first-episode psychosis, 53% smoked cigarettes, and heavy smokers had later onset of psychosis, worse cognition, and lower functioning than non-smokers, even after adjusting for cannabis use frequency.
Quick Facts
What This Study Found
In 140 patients entering specialized first-episode psychosis treatment, 53% smoked cigarettes: 47 were light/moderate smokers (1-19/day) and 27 were heavy smokers (20+/day). Smoking status was highly associated with cannabis use frequency.
After adjusting for cannabis use, significant differences remained. Heavy smokers were older at program entry and had a later age of psychosis onset. Non-smokers had more education, better neurocognitive performance, and higher functioning than both smoking groups.
These findings suggest that cigarette smoking has independent effects on cognition and function in psychosis, beyond what can be attributed to co-occurring cannabis use.
Key Numbers
140 FEP patients. 53% smoked cigarettes. 47 light/moderate (mean 9.8/day), 27 heavy (mean 26.4/day), 66 non-smokers. Heavy smokers: later psychosis onset. Non-smokers: more education, better cognition, higher functioning. Cannabis use: highly correlated with smoking status.
How They Did This
Cross-sectional analysis of 140 patients entering specialized first-episode psychosis treatment. Divided into non-smokers (n=66), light/moderate smokers (n=47), and heavy smokers (n=27). Analyses adjusted for cannabis use frequency to isolate cigarette-specific associations.
Why This Research Matters
Previous research on smoking and psychosis often failed to account for cannabis co-use, making it difficult to attribute effects to either substance. By statistically controlling for cannabis, this study shows that cigarette smoking carries its own independent associations with cognitive and functional outcomes in early psychosis.
The Bigger Picture
The extremely high smoking rate in psychosis (53% in this sample, compared to ~15-20% in the general population) is a major health concern. Finding that smoking's negative associations persist after adjusting for cannabis use strengthens the case for integrated smoking cessation as part of early psychosis treatment.
What This Study Doesn't Tell Us
Cross-sectional design cannot determine causation. Self-reported substance use may be inaccurate. Cannabis use was controlled statistically but not experimentally. The sample may not represent all first-episode psychosis patients. Potential confounders (socioeconomic status, premorbid functioning) may not be fully captured.
Questions This Raises
- ?Would smoking cessation in early psychosis improve cognitive and functional outcomes?
- ?Does nicotine have specific effects on psychosis neurobiology, or are the associations driven by general health and socioeconomic factors?
- ?Would longitudinal studies confirm these cross-sectional findings?
Trust & Context
- Key Stat:
- 53% of first-episode psychosis patients smoked; smoking independently linked to worse cognition
- Evidence Grade:
- Cross-sectional observational study with appropriate statistical adjustment for cannabis use. Good design for identifying independent associations.
- Study Age:
- Published in 2017. Integrated smoking cessation in early psychosis treatment continues to be advocated.
- Original Title:
- Smoking status and its relationship to demographic and clinical characteristics in first episode psychosis.
- Published In:
- Journal of psychiatric research, 85, 83-90 (2017)
- Authors:
- Grossman, Michael, Bowie, Christopher R(2), Lepage, Martin, Malla, Ashok K, Joober, Ridha, Iyer, Srividya N
- Database ID:
- RTHC-01391
Evidence Hierarchy
Watches what happens naturally without intervening.
What do these levels mean? →Frequently Asked Questions
Do people with psychosis smoke because of the illness or vice versa?
This study cannot determine the direction. Smoking may be used to self-medicate symptoms, or shared genetic/environmental factors may predispose to both. The high smoking rate (53%) likely reflects multiple contributing factors.
Is cannabis or tobacco worse for psychosis outcomes?
This study found that after controlling for cannabis use, cigarette smoking still had independent negative associations with cognition and functioning. Both substances appear to have distinct effects, suggesting both should be addressed in treatment.
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Cite This Study
https://rethinkthc.com/research/RTHC-01391APA
Grossman, Michael; Bowie, Christopher R; Lepage, Martin; Malla, Ashok K; Joober, Ridha; Iyer, Srividya N. (2017). Smoking status and its relationship to demographic and clinical characteristics in first episode psychosis.. Journal of psychiatric research, 85, 83-90. https://doi.org/10.1016/j.jpsychires.2016.10.022
MLA
Grossman, Michael, et al. "Smoking status and its relationship to demographic and clinical characteristics in first episode psychosis.." Journal of psychiatric research, 2017. https://doi.org/10.1016/j.jpsychires.2016.10.022
RethinkTHC
RethinkTHC Research Database. "Smoking status and its relationship to demographic and clini..." RTHC-01391. Retrieved from https://rethinkthc.com/research/grossman-2017-smoking-status-and-its
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.