Our aim was to analyze whether depressive symptoms mediated the association between physical quality of life (QoL) and adherence to physical activity in patients with non-alcoholic fatty liver disease (NAFLD), as well as the association between social support and adherence to diet. We also examined whether self-efficacy exerted a moderating role in these associations. QoL (SF-12), social support (MSPSS), depressive symptoms (HADS), self-efficacy (GSE), physical activity (IPAQ) and diet (MEDAS) were evaluated in 413 biopsy-proven NAFLD patients. Mediation and moderated mediation models were conducted using the SPSS PROCESS v3.5 macro. Results showed that depressive symptoms mediated the relationship between physical QoL and adherence to physical activity (indirect effect = 6.248, CI = 1.917-10.727), as well as the relationship between social support and adherence to diet (indirect effect = 0.148, CI = 0.035-0.275). Self-efficacy also moderated the indirect effects of QoL and social support on therapeutic adherence through depressive symptoms. Specifically, the higher self-efficacy was, the lower the negative impact on the NAFLD patient's mental health. In conclusion, self-efficacy is defined as a protective factor for therapeutic adherence by NAFLD patients with a psychosocial risk profile. Self-efficacy should, therefore, be a main psychological target in future multidisciplinary NAFLD approaches.
Keywords: Mediterranean diet; NAFLD; depressive symptoms; physical activity; quality of life; self-efficacy; social support; therapeutic adherence.