Can an Acceptance and Commitment Therapy-Based Smartphone App Help Individuals with Mental Health Disorders Quit Smoking?

Background. Individuals with mental health disorders face major barriers in accessing smoking cessation care, often due to the stigmas associated with mental disorders and addiction. Consequently, accessible population-based smoking cessation interventions are needed for this vulnerable group. Objective. This secondary analysis utilized data from a 12-month randomized trial to examine whether an acceptance and commitment therapy-based app (iCanQuit) demonstrated greater efficacy, engagement, and satisfaction compared to a United States (US) Clinical Practice Guidelines-based app (QuitGuide) in helping adults with mental health disorders quit smoking. Materials and Methods. Participants self-reported having bipolar disorder or schizophrenia, or screened positive for depression, generalized anxiety, panic disorder, posttraumatic stress disorder, or social anxiety. We compared the primary outcome of self-reported 30-day cigarette abstinence at 12 months between iCanQuit (n = 770) and QuitGuide (n = 785) using complete-case and multiple imputation analyses and compared engagement and satisfaction between arms. Mediation analyses were conducted to examine whether the intervention apps functioned by reinforcing hypothesized mechanisms of action, namely, acceptance of triggers to smoke and through app engagement. Results. Participants represented all 50 US states and had 30.2% non-White or Hispanic backgrounds. Among participants with any mental health disorder, iCanQuit demonstrated higher 30-day cigarette abstinence than QuitGuide at 12 months (complete-case: 24.4% vs. 20.4%, P = 0.04; multiple imputation: 24.6% vs. 20.4%, P = 0.04). A comparable effect size was observed in iCanQuit participants with bipolar disorder or schizophrenia compared to QuitGuide, albeit not statistically significant (multiple imputation: 27.1% vs. 20.9%; P = 0.06). iCanQuit’s cessation efficacy was mediated by acceptance of emotions triggering smoking (P < 0.001) and app engagement (P < 0.001). iCanQuit was more satisfying than QuitGuide (88.5% vs. 77.2%; P < 0.001). Conclusions. In the largest known study of ACT for smoking cessation among adults with mental health disorders, the smoking cessation, engagement, and satisfaction outcomes were all significantly greater with iCanQuit than QuitGuide. Acceptance of emotions triggering smoking and iCanQuit app engagement were important mechanisms of efficacy. This trial is registered with NCT02724462.