“…Major depressive disorder (MDD) is a widespread and debilitating mood disorder that impacts a substantial number of individuals globally [ 67 , 77 , 78 , 79 ]. Characterized by persistent feelings of sadness, reduced interest, diminished self-worth, and various physical and mental symptoms, it often co-occurs with other conditions, such as anxiety, chronic pain, and neurodegenerative diseases [ 80 , 81 , 82 , 83 ]. In this special issue, three articles explored different approaches for diagnosing and treating depression and its comorbidities [ 84 , 85 , 86 ].…”