Smoking & Psychosis Risk: Brain Connectivity Unchanged

Recent research suggests that smoking isn’t directly linked to changes in brain network function among individuals considered to be at clinical high risk for developing psychosis. This finding, reported by Medscape News UK, adds nuance to the complex relationship between tobacco use and mental health, particularly in those who may be predisposed to psychotic disorders.

Understanding Clinical High Risk for Psychosis

The study focuses on individuals identified as being at ‘clinical high risk’ (CHR) for psychosis. This doesn’t mean they will definitely develop a psychotic disorder like schizophrenia, but they exhibit early warning signs – subtle experiences or behaviors that suggest an increased vulnerability. These signs can include unusual thought patterns, perceptual disturbances (like mild hallucinations), or a decline in functioning. Identifying individuals at CHR is crucial because early intervention can potentially alter the course of illness. The North American Prodrome Longitudinal Study, referenced in research on this topic, aims to understand these predictors and mechanisms better.

For years, there’s been an observed association between smoking and psychosis. People diagnosed with psychotic disorders are significantly more likely to smoke than the general population – rates can be as high as 70-80% in some patient groups. This has led to several hypotheses, including the idea that nicotine might somehow contribute to the development of psychosis, or that individuals experiencing early psychotic symptoms self-medicate with nicotine. However, establishing a causal link has proven difficult.

What the Modern Research Reveals

The recent findings challenge the notion of a direct causal relationship. Researchers found no evidence that smoking alters the way large-scale brain networks communicate in individuals at CHR. This was assessed through functional connectivity analysis, a technique that measures the correlation between activity in different brain regions. Essentially, the study suggests that smoking doesn’t fundamentally change how the brain *works* in these vulnerable individuals.

It’s important to note that this doesn’t negate the existing association between smoking and psychosis. Instead, it suggests that other factors might be at play. A systematic review and meta-analysis published in Schizophrenia Research highlights the complexity of this association, noting that several hypotheses exist to explain the higher rates of tobacco use in individuals with psychosis, but the reasons remain unclear.

Unpacking the Association: Why Do People at Risk Smoke More?

The research points to shared underlying vulnerabilities. Individuals at CHR are more likely to experience factors commonly associated with smoking in the general population, such as mood disorders, substance use, stress, trauma and perceived discrimination. The original study from 2018 found that clinical high risk subjects reported higher rates of these factors. These factors, rather than nicotine itself, may be driving both the increased smoking rates and the increased risk of psychosis.

the study found that baseline smoking status and whether someone had ever smoked did not predict the transition to a full psychotic episode. This suggests that smoking isn’t a predictor of *developing* psychosis, but rather may be a consequence of the vulnerability itself.

Cannabis and Tobacco: A Combined Risk?

The interplay between cannabis and tobacco use also warrants consideration. Research published in September 2025 indicates that co-use of cannabis and tobacco predicts psychosis in clinical high-risk individuals. This suggests that the combination of substances may pose a greater risk than either substance alone, potentially due to synergistic effects on brain development and function.

Limitations and Future Directions

Like all research, this study has limitations. It’s important to remember that correlation does not equal causation. While the study doesn’t identify evidence that smoking *causes* changes in brain networks, it doesn’t entirely rule out a more complex, indirect relationship. The study relied on self-reported smoking data, which can be subject to recall bias. The study population may not be fully representative of all individuals at CHR.

Further research is needed to fully unravel the relationship between smoking, cannabis, and psychosis. Longitudinal studies that track individuals at CHR over time, combined with neuroimaging and genetic analyses, will be crucial. Investigating the specific mechanisms by which shared vulnerabilities – like stress and trauma – contribute to both smoking and psychosis is also essential.

What Comes Next: Surveillance and Guidance Updates

The findings don’t necessitate an immediate change in clinical practice. However, they reinforce the importance of comprehensive assessment and intervention for individuals at CHR. Clinicians should focus on addressing underlying vulnerabilities – such as mood disorders, substance use, and trauma – rather than solely targeting smoking cessation. Public health initiatives aimed at preventing smoking and substance use among young people remain crucial, particularly for those identified as being at risk for mental health problems.

Ongoing surveillance of smoking rates and substance use patterns among individuals at CHR will be important to monitor trends and inform future research. Regular reviews of the evidence by organizations like the National Institute of Mental Health (NIMH) will help to refine our understanding of this complex relationship and guide clinical recommendations.