['To investigate the association between levels of psychological distress and smoking and quitting behaviours.', "Data were from two large Australian national household surveys of individuals over 20 years of age. Level of psychological distress was measured by the Kessler 10 scale. Tobacco smoking measures included current smoking status (never, former, current); ex-smokers' time since quitting; current smokers' abstinent period in the last 12 months, cigarettes smoked per day, reasons for smoking, and self-report of factors that would motivate quitting; and self-report of factors that motivated smokers to quit in the last 12 months. Multinomial logistic regression was used to assess the relationships between smoking behaviours and psychological distress, while controlling for socio-demographic factors.", 'Current smokers, especially those who smoke more cigarettes per day and those who report less success at quitting or reducing smoking, had higher levels of psychological distress. Ex-smokers were also more likely to experience psychological distress than those who never smoked, but the association weakened with more years since quitting. Current smokers with psychological distress were just as, or more likely, to report planning to quit as those without psychological distress. Smokers who did not plan to quit due to addiction, past failure at quitting, and using smoking for relaxation or to deal with stress were more likely to report psychological distress than those who did not report these reasons.'] Is psychological distress associated with tobacco smoking and quitting behaviour in the Australian population : evidence from national cross-sectional surveys?