Centre for Brain and Cognitive Development, Department of Psychological Sciences, Birkbeck University of London, Malet Street, London, WC1E 7HX, UK.
Department of Clinical, Educational and Health Psychology, University College London, London, UK.
Sci Rep. 2021 Jul 21;11(1):14871. doi: 10.1038/s41598-021-93962-7.
Cigarette smoking is a modifiable behaviour associated with mental health. We investigated the degree of genetic overlap between smoking behaviours and psychiatric traits and disorders, and whether genetic associations exist beyond genetic influences shared with confounding variables (cannabis and alcohol use, risk-taking and insomnia). Second, we investigated the presence of causal associations between smoking initiation and psychiatric traits and disorders. We found significant genetic correlations between smoking and psychiatric disorders and adult psychotic experiences. When genetic influences on known covariates were controlled for, genetic associations between most smoking behaviours and schizophrenia and depression endured (but not with bipolar disorder or most psychotic experiences). Mendelian randomization results supported a causal role of smoking initiation on psychiatric disorders and adolescent cognitive and negative psychotic experiences, although not consistently across all sensitivity analyses. In conclusion, smoking and psychiatric disorders share genetic influences that cannot be attributed to covariates such as risk-taking, insomnia or other substance use. As such, there may be some common genetic pathways underlying smoking and psychiatric disorders. In addition, smoking may play a causal role in vulnerability for mental illness.
吸烟是一种与心理健康相关的可改变行为。我们研究了吸烟行为与精神特质和障碍之间的遗传重叠程度，以及遗传相关性是否存在于与混杂变量（大麻和酒精使用、冒险行为和失眠）共享的遗传影响之外。其次，我们调查了吸烟开始与精神特质和障碍之间是否存在因果关联。我们发现吸烟与精神障碍和成年精神病体验之间存在显著的遗传相关性。当控制了已知协变量的遗传影响时，大多数吸烟行为与精神分裂症和抑郁症之间的遗传关联仍然存在（但与双相情感障碍或大多数精神病体验无关）。孟德尔随机化结果支持吸烟开始对精神障碍和青少年认知和阴性精神病体验的因果作用，尽管并非在所有敏感性分析中都一致。总之，吸烟和精神障碍共享遗传影响，这些影响不能归因于冒险行为、失眠或其他物质使用等混杂变量。因此，吸烟和精神障碍可能存在一些共同的遗传途径。此外，吸烟可能在精神疾病易感性中起因果作用。
