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Background: Tobacco use is common in subjects with schizophrenia (SZ) and has sometimes been associated with better functioning in short-term studies. Only few studies embrace an extensive examination of tobacco influence on clinical, cognitive and therapeutic characteristics in stabilized SZ outpatients. The objective of the present study was to assess the association between cognitive performances and smoking status in SZ subjects. Methods: In total, 1233 SZ participants (73.9% men, mean age 31.5) were included and tested with a comprehensive battery. Tobacco status was self-declared (never-, ex-, or current smokers). Multivariable analyses including principal component analyses (PCA) were used. Results: In total, 53.7% were smokers with 33.7% of them nicotine-dependent. Multiple factor analysis revealed that current tobacco smoking was associated with impaired general intellectual ability and abstract reasoning (aOR 0.60, 95% IC 0.41–0.88, p = 0.01) and with a lifetime alcohol use disorder (p = 0.026) and a lifetime cannabis use disorder (p < 0.001). Ex- and never-smokers differed for age, mean outcome, cannabis history and medication [ex-smokers being older (p = 0.047), likely to have higher income (p = 0.026), a lifetime cannabis use disorder (p < 0.001) and higher CPZeq doses (p = 0.005)]. Premorbid IQ in the three groups significantly differed with, from higher to lower: ex-smokers, never-smoker, current smokers (all p < 0.001). Conclusions: This study is the largest to date providing strong evidence that chronic smoking is associated with cognitive impairment in SZ, arguing against the self-medication hypothesis as a contributor to the high prevalence of smoking in SZ. Ex-smokers may also represent a specific subgroup. Longitudinal studies are warranted to determine the developmental impact of tobacco on neurocognition. [ABSTRACT FROM AUTHOR]

Background: Bipolar disorder (BD) is a complex and heterogeneous psychiatric disorder. Neurodevelopmental factors were suggested to contribute to the etiology of BD, yet a specific neurodevelopmental phenotype of the disorder remains unidentified. Our objective was to define and characterize a neurodevelopmental phenotype (NDP) in BD and validate its associations with clinical outcomes, polygenic risk scores (PGS), and treatment responses., Method: We analyzed the FACE-BD cohort of 4,468 BD patients, a validation cohort of 101 BD patients, and two independent replication datasets of 274 and 89 BD patients. Using factor analyses, we identified a set of criteria for defining NDP. We next developed a scoring system for NDP-load and assessed its association with prognosis, neurological soft signs, polygenic risk scores for neurodevelopmental disorders, and responses to treatment using multiple regressions, adjusted for age and sex with bootstrap replications., Results: Our study established a NDP in BD consisting of nine clinical features: advanced paternal age, advanced maternal age, childhood maltreatment, attention deficit hyperactivity disorder (ADHD), early onset of BD, early onset of substance use disorders, early onset of anxiety disorders, early onset of eating disorders, specific learning disorders. Patients with higher NDP-load showed a worse prognosis and increased neurological soft signs. Notably, these individuals exhibited a poorer response to lithium treatment. Furthermore, a significant positive correlation was observed between the NDP-load and PGS for ADHD suggesting potential overlapping genetic factors or pathophysiological mechanisms between BD and ADHD., Conclusions: The proposed NDP constitutes a promising clinical tool for patient stratification in BD., (Copyright © 2024. Published by Elsevier Inc.)