Attitudes about smoking cessation treatment, intention to quit, and cessation treatment utilization among young adult smokers with severe mental illnesses

•After brief intervention, a third of young adult smokers with SMI reported quit attempts.•Breath CO, intention to quit and symptom distress were related to quit attempts.•Attitudes and perceived behavioral control correlated with cessation treatment intention.•Beliefs about cessation treatment improved after the interactive intervention.•Intentions to use treatment remained low, in line with low use of treatment.