Randomized Controlled Trial of a Group-Based Smoking Cessation Intervention for Adults With Serious Mental Illness

Abstract Introduction Adults with serious mental illness (SMI) have elevated morbidity and mortality, largely attributable to increased cigarette smoking. Effective smoking cessation interventions remain a critical need for this population. This study tested the Parks and Recreation Quit Smoking Program (PARQuit), a multi-component treatment program for adults with SMI. The aims were to compare the effectiveness of the PARQuit physical activity and PARQuit sedentary groups on smoking cessation, smoking reduction, and psychiatric symptom reduction. Methods Ninety-nine participants with SMI were randomized to a physical activity intervention or a sedentary control group, each receiving pharmacotherapy (nicotine replacement therapy (NRT) or bupropion SR) and cessation counseling for 12 weeks in the United States of America, from 2019 through 2025. The PARQuit physical activity group engaged in game-based group exercise (50 minutes, 3 times/week), whereas the PARQuit sedentary group participated in sedentary group activities. Outcomes included smoking cessation (measured at baseline, 6, and 12 weeks) and psychiatric symptoms assessed via the Brief Psychiatric Rating Scale. Results At baseline, participants smoked a mean of 76 cigarettes per week, declining to 35 cigarettes at 12 weeks. Both groups showed a significant linear decline in cigarette consumption over time (mean change: -3.7 cigarettes/week; 95% CI: -5.2, -2.4), with no significant between-group difference. Smoking abstinence increased significantly (McNemar χ2=5.33, p.05). Psychiatric symptoms decreased continually, with scores dropping by 0.29 units per week (95% CI: -0.50, -0.09) in both groups. Conclusions Although there were no significant differences between study groups, both study groups showed a significant reduction in cigarettes smoked each week and in psychiatric symptoms. Group-based counseling and pharmacotherapy likely contributed to these improvements. Future research should assess longer-term outcomes in sustaining smoking cessation. Clinical Trials Registration Number: NCT03950427.