Cigarette smoking is associated with thinner cingulate and insular cortices in patients with severe mental illness.

BACKGROUND: Magnetic resonance imaging (MRI) studies show reduced cortical thickness in patients with schizophrenia and bipolar disorder. These subtle brain abnormalities may provide insight into illness mechanisms. However, environmental and lifestyle-related factors, such as cigarette smoking, may contribute to brain structure changes. Cigarette smoking is highly prevalent in patients with severe mental illness. In nonpsychiatric samples, smoking has been associated with reduced thickness in the anterior (ACC) and posterior cingulate cortices, the insular cortex (INS), the dorsolateral prefrontal cortex and the orbitofrontal cortex. METHODS: We examined MRI scans from patients with schizophrenia, other psychotic disorders or bipolar disorder and healthy controls using FreeSurfer. RESULTS: We included 506 patients (49% smokers) and 237 controls (20% smokers) in our study. We found reduced cortical thickness in the left rostral ACC and the left INS in smoking patients compared with nonsmoking patients, but this difference was not found among healthy controls. No dose-response relationship was found between amount of smoking and cortical thickness in these regions. Among patients, maps of thickness along the whole cortical surface revealed reduced insular thickness but no effects in other regions. Among healthy controls, similar analyses revealed increased age-related cortical thinning in the left occipital lobe among smokers compared with nonsmokers. LIMITATIONS: The causal direction could not be determined owing to the cross-sectional design and lack of detailed data on smoking addiction and smoking history. CONCLUSION: The effect of cigarette smoking should be considered in MRI studies of patients with severe mental illness.

One year follow-up of alcohol and illicit substance use in first-episode psychosis: does gender matter?

Longitudinal studies on first-episode psychosis (FEP) patients have shown a decrease of substance use disorders (SUDs) over the first years of illness, but there has been less focus on the gender aspect. The present study examines stability of alcohol and illicit substance use, with specific focus on gender, in a one year follow-up investigation of 154 FEP patients (91 men, 63 women) in Oslo, Norway, using criteria for DSM-IV substance use disorder diagnosis, the Alcohol Use Disorders Identification Test (AUDIT) and the Drug Use Disorders Identification Test (DUDIT). The results show that cannabis was the most frequently used illicit substance at both times. Significantly more men (34%) than women (13%) had a current illicit SUD at baseline. At follow-up, the rate of illicit SUDs was significantly reduced in men (18%) but not in women (11%). There were no significant gender differences in the rate of current alcohol use disorders (AUD) (men 14%; women 8%) at baseline, and no significant reduction in AUD in any of the genders at follow-up. At follow-up, total AUDIT and DUDIT scores were reduced in men only. In conclusion, the high and persistent rate of SUDs, particularly of cannabis, among men and women during the first year of treatment for psychosis should be addressed in the clinical management of the patients. Female FEP patients who are also substance users may be particularly vulnerable in this regard and warrant closer attention.