Cigarette smoking trends among persons with psychiatric disorders: 1999-2026.

Cigarette smoking remains the leading preventable cause of premature mortality in individuals with mental illness. Smoking prevalence has declined substantially over the past quarter-century in the US general population, but whether these gains have extended to psychiatric populations and whether they differ across diagnoses is unknown. The number of cigarettes smoked per day represents an additional and largely understudied issue. We examined 2441 individuals enrolled between 1999 and 2026 without regard to their smoking status: 933 with schizophrenia, 657 with bipolar disorder, 231 with major depressive disorder (MDD), and 620 non-psychiatric controls. Based on data obtained at study entry, overall smoking prevalence was 61.2% in persons with schizophrenia, 34.6% in bipolar disorder, 17.3% in MDD, and 16.0% in controls. Modified Poisson regression examined by year of entry revealed significant declines in smoking prevalence among controls (PR = 0.92; 95% CI, 0.88-0.96), bipolar disorder (PR = 0.97; 95% CI, 0.95-0.99), and MDD (PR = 0.95; 95% CI, 0.90-1.00). By contrast, individuals with schizophrenia showed no significant change (PR = 0.99; 95% CI, 0.99-1.00) in the prevalence of smoking among persons enrolled over the study period. Significant annual declines in the number of cigarettes smoked per day were observed in all groups. In conclusion, individuals with schizophrenia have not shared in the national decline in cigarette smoking prevalence over the past 25 years. However, daily consumption has declined significantly, paralleling the pattern in other groups. These divergent trends highlight the need for targeted cessation interventions that promote smoking cessation in individuals with schizophrenia.