Relationship Between Smoking and Psychiatric and Somatic Comorbidities in Older Age Bipolar Disorder: Lien entre le tabagisme et les affections psychiatriques et somatiques concomitantes chez les personnes âgées atteintes de trouble bipolaire

ObjectiveSmoking has been associated with psychiatric and somatic comorbidities in bipolar disorder (BD) populations. However, studies in older age BD (OABD) populations are sparse. We hypothesized that among individuals with OABD, current and former smokers would have worse psychiatric and somatic comorbidities parameters compared to never smokers.MethodOur study used baseline cross-sectional data from 27 international studies reporting data on adults 50 years old and older (<i>N</i> = 984). Smoking status was categorized into current smokers, former smokers, and never smokers. The distribution of demographic and clinical variables was assessed. The associations between smoking status and the clinical variables were examined using multivariable models that adjusted for age, sex, and study. Multivariable models were repeated, restricting to individuals with and without cardiovascular or respiratory (cardiorespiratory) comorbidity.ResultsOur study sample was 52.8% female with a mean age of 62 years and included 347 (35.3%) never smokers, 222 (22.6%) former smokers, and 415 (42.2%) current smokers. After controlling for age, sex, and study, current depression was more prevalent in former versus never smokers and current versus never smokers. Cardiovascular comorbidity was more prevalent among former than never smokers. More current versus never smokers were taking antipsychotic medications and more current versus never smokers having lifetime substance use disorders. When stratifying by the presence of cardiorespiratory comorbidity, the only statistically significant association was higher functioning in never versus current smokers in participants without cardiorespiratory comorbidity, though non-statistically significant relationships were present between lifetime smoking and depression across strata.ConclusionsThe relationship of smoking with depression and substance use disorders is largely independent of age, sex, and, for the depression relationship, cardiorespiratory comorbidity. More smokers taking antipsychotic medications suggests that smoking is associated with a more severe BD course. Cardiovascular comorbidity may serve as a motivating factor for smoking cessation.