The social and healthcare burden of major depressive disorder in adults: an Italian observational cohort study

Major Depressive Disorder (MDD) is a leading cause of disability worldwide, with significant economic and social burden. However, studies assessing the overall socio-economic burden (direct, indirect and intangible costs) are scarce. This study aims to evaluate the socioeconomic burden imposed by MDD on patients referred to specialist medical centers in Italy. An observational, multicenter, longitudinal cost of illness study was conducted on patients aged 18–65 years with a diagnosis of MDD starting antidepressant therapy. Healthcare resources consumption and productivity loss were collected over 1-year follow-up to estimate per-patients MDD costs. Depressive symptoms were assessed with various clinical scales. Health Related Quality of Life (HRQoL) was assessed with the EQ-5D-5 L. MDD severity decreased during the observational period, as reported by all clinical scales, with a notable improvement in HRQoL scores. The main costs associated with MDD patients were indirect costs, €386.3 per patient-month at baseline, declining to €179.9 in the last 6 months. Direct medical costs peaked in the first 3 months (€155.9 per patient-month), compared to baseline (€55,09 per patient-month), then decreased. Costs were significantly associated with and increased with the number of depressive episodes (129.71;7.59-251.83) and the augmentation of Quick Inventory of Depressive Symptomatology-Self Rated (QIDS-SR16) score (7.92;2.02–13.82). Our results suggest that MDD is a mental health issue with socio-economic burden that varies with symptoms severity. Indirect costs represent the main expense for MDD patients. These findings highlight the complexity and burden of MDD, emphasizing the importance of prioritizing depressive disorders in public health. • Major Depressive Disorder (MDD) is a leading cause of disabilities worldwide, with significant economic and social impacts. • During the study period, MDD severity decreased as reported by clinical scales and an improvement of HRQoL was observed. • Economic burden was driven by indirect costs. As regard, the direct medical costs, these increased during the first 3 months and then decreased overtime. • The number of depressive episodes and the increase in QIDS-SR16 score were factors that significantly influenced the disease costs. • MDD is associated with high socio-economic burden, emphasizing the importance of including MDD as a public-health priority.