Short- and long-term effects of emotion regulation mediation on quality of life domains in transdiagnostic cognitive-behavioral therapy

INTRODUCTION: Transdiagnostic cognitive-behavioral therapy (TD-CBT) has shown efficacy in reducing emotional symptoms and improving quality of life (QoL) in the primary care setting. However, less is known about the potential mediating processes of change, particularly the indirect effects through emotion regulation strategies (ERS). The present study aimed to examine whether cognitive reappraisal, suppression, negative metacognition, rumination, and worry (measured at post-treatment) account for the effect of TD-CBT (vs. treatment-as-usual [TAU]) on QoL domains (physical, psychological, social, and environmental) at 3- and 12-month follow-up. METHODS: Multivariate mediation analyses were conducted using the PROCESS macro for SPSS, with 10,000 bootstrap resamples. Treatment group assignment (TAU vs. TAU + TD-CBT) was included as the independent variable. Five ERS were included as potential mediators and QoL domains at 3 and 12 months as dependent variables, adjusted for baseline levels of both ERS and QoL variables. RESULTS: Negative metacognition and worry accounted for the primary indirect effects on physical and psychological QoL at both 3 and 12 months. Regarding cognitive reappraisal, a limited impact was observed on psychological and environmental QoL. Rumination yielded a modest indirect effect on psychological and social QoL, although the model explained a substantial proportion of its variance. Finally, suppression did not reach significance as a mediator in any model. Overall, the models accounted for 30% to 50% of the variance across QoL domains. Mediation analyses highlighted the specific role of TD-CBT in modifying these psychological mechanisms to improve long-term QoL, a process that does not occur with TAU alone. CONCLUSION: These findings highlight the relevance of ERS-particularly worry and negative metacognition-as key variables associated with long-term improvements in TD-CBT. Clinically, these results suggest that primary care interventions should prioritize reducing maladaptive ERS to achieve sustained gains in QoL.