Major Depressive Disorder (MDD) is the most prevalent mental disorder in the world, with high rates of recurrence and dysfunction. A significant portion of patients do not respond adequately to conventional treatments, highlighting the need to search for biomarkers capable of predicting clinical response.
A relevant marker in depression is attentional bias, which is characterized by the preferential processing of negative stimuli, and is inferred as a useful tool in the diagnosis and treatment of depression. The best way to measure attentional bias is through eye-tracking.
In a smaller body of evidence, it is indicated that pharmacological treatment of depression is able to modify the visual tracking pattern, directing it towards a tendency towards normalization when compared to healthy controls, and that this precedes the clinical response.
The study proposes a single-case, blinded design conducted at the Institute of Psychiatry of the HC-FMUSP to evaluate whether visual tracking patterns obtained by eye-tracking in the first weeks of treatment with brexpiprazole (1 and 2 mg/day) as an adjunct in adults with MDD are able to predict clinical response when compared to placebo.
The primary outcome will be measured by the MADRS questionnaire and the secondary outcome by the Clinical Global Impression (CGI). The eye-tracking assessment will use the Tobii eye-tracker 250 Hz device, with images from the International Affective Picture System (IAPS), and will be performed weekly over 10 weeks. It is expected to establish eye-tracking as a low-cost tool to assist in predicting therapeutic response in depression.