Serial mediation between self-efficacy and motivation as a mechanism of change in tobacco cessation: analysis of the Guided Self-Change therapy effectiveness

AbstractBackground Behavioral interventions are effective for smoking cessation; however, little is known about the underlying mechanisms of treatment outcomes. Self-efficacy and motivation to quit are two central mediators of therapy success, however, their interaction during tobacco cessation remains unclear. The aims of this study were to analyze the effectiveness of Guided Self-Change (GSC) therapy for smoking cessation and to examine parallel and serial mediation between self-efficacy and motivation during therapy.Method We conducted a one-group pretest-posttest design with the participation of 145 treatment-seeking smokers (age = 55.8 ± 10.3 years; 59.3% women) from the General University Hospital of Alicante. We assessed participants’ daily tobacco use, self-efficacy, and motivation to quit at baseline and at the end of treatment. Descriptive, bivariate, and mediation analyses were performed.Results A total of 49% (n = 71) of participants completed GSC therapy (3–5 sessions), of which 52.1% (n = 37) stopped using tobacco after treatment (McNemar’s p < 0.001; θ = 5.85). Mediation analyses showed GSC therapy significantly increased (p < 0.01) both self-efficacy (a1=1.19; 95%CI = 0.47, 1.91) and motivation (a2=1.95; 95%CI = 1.34, 2.56). However, only the serial path from self-efficacy to motivation to quit showed significant indirect effects in tobacco reduction (a1a3b2=–0.29; 95%CI=–1.1, 0.03; Z=–4.36; p < 0.001).Conclusions GSC therapy demonstrated effectiveness in quitting smoking by partially increasing self-efficacy, which in turn enhanced motivation to quit leading to a reduction of use. These findings expand empirical knowledge about theorized mechanisms of change in addictive behaviors that could contribute to improving psychological interventions.Keywords: Motivationself-efficacytobaccosmokingmediationbehavior change AcknowledgmentsAuthors declare no acknowledgments.Ethical approvalThis study was approved by the Clinical Research Ethics Committee of the GUHA (Reference: PI2019/096). All participants were informed of the study characteristics and all participants provided informed consent before starting the study.Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingC.S.-D. is supported by a predoctoral fellowship from the Ministry of Innovation, Universities, Science and Digital Society of Generalitat Valenciana, and the European Social Fund (ACIF/2021/383).