Abnormal eye movement patterns in adolescent and early adulthood MDD patients with and without psychotic symptoms: A...

Major depressive disorder (MDD) heterogeneity is frequently overlooked in current diagnostic approaches, despite evidence that certain subtypes, particularly MDD with psychotic symptoms (MDDwP), are associated with poorer prognoses. Eye movement assessment has demonstrated promise as a potential biomarker for psychiatric disorders; however, research into eye movement patterns in MDD with and without psychotic features is scarce. This study aimed to investigate the potential value of eye movement as a biomarker for MDD.

This study enrolled 69 participants, including 15 patients with major depressive episodes without psychotic symptoms (MDDwoP), 17 patients with MDDwP, and 37 healthy controls (HC). Eye-movement characteristics were collected using three paradigms: smooth tracking, dual-task tracking, and free viewing.

No significant differences emerged among groups in smooth tracking (P> 0.05). In the dual-task tracking, the MDDwP group had a greater number of excursions (P= 0.008) and a greater total excursion (P= 0.023) than the HC group. In the free-viewing task, patients in both groups exhibited significantly higher saccade counts (P= 0.031 for both groups) and fixation counts (P= 0.013; P= 0.025) than the HC group.

Patients with MDDwP have specific eye movement abnormalities indicating impaired attention allocation and multitasking abilities. The alterations observed in both depressed groups likely reflect compensatory cognitive resource allocation. These distinctive patterns provide evidence supporting eye-tracking technology as a potential objective diagnostic biomarker for MDD subtypes.