University of Paris, INSERM UMR1266, Institute of Psychiatry and Neuroscience of Paris, Paris, France.
AP-HP, Department of Psychiatry, Louis Mourier Hospital, Colombes, France.
Psychol Med. 2023 Aug;53(11):5279-5290. doi: 10.1017/S0033291722002574. Epub 2022 Sep 8.
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.
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.
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, = 0.01) and with a lifetime alcohol use disorder ( = 0.026) and a lifetime cannabis use disorder ( < 0.001). Ex- and never-smokers differed for age, mean outcome, cannabis history and medication [ex-smokers being older ( = 0.047), likely to have higher income ( = 0.026), a lifetime cannabis use disorder ( < 0.001) and higher CPZeq doses ( = 0.005)]. Premorbid IQ in the three groups significantly differed with, from higher to lower: ex-smokers, never-smoker, current smokers (all < 0.001).
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.
吸烟在精神分裂症患者中很常见，有时与短期研究中的更好的功能相关。只有少数研究广泛考察了吸烟对稳定的精神分裂症门诊患者的临床、认知和治疗特征的影响。本研究的目的是评估精神分裂症患者的认知表现与吸烟状况之间的关系。
共纳入 1233 名精神分裂症患者（73.9%为男性，平均年龄 31.5 岁），并进行全面的测试。吸烟状况由自我报告（从未吸烟、曾吸烟或当前吸烟）。采用多变量分析包括主成分分析（PCA）。
共有 53.7%的患者吸烟，其中 33.7%为尼古丁依赖者。多因素分析显示，当前吸烟与一般智力能力和抽象推理受损相关（优势比 0.60，95%置信区间 0.41-0.88， = 0.01），与终身酒精使用障碍（ = 0.026）和终身大麻使用障碍相关（<0.001）。曾吸烟者和从不吸烟者在年龄、平均结局、大麻史和药物治疗方面存在差异[曾吸烟者年龄较大（ = 0.047），可能收入较高（ = 0.026），有终身大麻使用障碍（<0.001）和更高的氯氮平等效剂量（ = 0.005）]。三组患者的前病智商差异显著，从高到低依次为：曾吸烟者、从不吸烟者、当前吸烟者（均<0.001）。
这项研究是迄今为止规模最大的研究，提供了强有力的证据表明，慢性吸烟与精神分裂症患者的认知障碍相关，这与自我用药假说不一致，该假说认为吸烟在精神分裂症中的高患病率是由自我用药引起的。曾吸烟者也可能代表一个特定的亚组。需要进行纵向研究来确定吸烟对神经认知的发展影响。
