Physical and mental health status of former smokers and non-smokers patients with bipolar disorder.

OBJECTIVES: Up to 70% individuals with bipolar disorder (BD) are lifetime tobacco smokers, a major modifiable risk factor for morbidity. However, quitting smoking is rarely proposed to individuals with BD, mainly because of fear of unfavorable metabolic or psychiatric changes. Evaluating the physical and mental impact of tobacco cessation is primordial. The aim of this study was to characterize the psychiatric and non-psychiatric correlates of tobacco smoking status (never- versus current vs former smokers) in individuals with BD.

METHODS: 3,860 individuals with ascertained BD recruited in the network of Fondamental expert centers for BD between 2009 and 2020 were categorized into current, former, and never tobacco smokers. We compared the sociodemographic and clinical characteristics assessed by standard instruments (e.g. BD type, current symptoms load, and non-psychiatric morbidity - including anthropometric and biological data) of the three groups using multinomial regression logistic models. Corrections for multiple testing were applied.

RESULTS: Current smokers had higher depression, anxiety, and impulsivity levels than former and never-smokers, and also higher risk of comorbid substance use disorders with a gradient from never to former to current smokers - suggesting shared liability. Current smokers were at higher risk to have a metabolic syndrome than never-smokers, although this was only evidenced in cases, who were not using antipsychotics.

CONCLUSIONS: Tobacco smoking was associated with high morbidity level. Strikingly, as in the general population, quitting smoking seemed associated with their return to the never-smokers' levels. Our findings strongly highlight the need to spread strategies to treat tobacco addiction in the BD population.