Studies using near-infrared spectroscopy (NIRS) found hemodynamic alterations in the brain prefrontal area of individuals with major depressive disorder (MDD) during a short interval of 4 weeks. The use of NIRS signals could reveal trait markers useful in individuals with MDD and holds value as a biological marker for predicting the clinical response to sertraline treatment, according to a study published in the Journal of Affective Disorders.
In this study, investigators wanted to assess if the hypofrontality observed in individuals with MDD varies between the antidepressant treatment and improvement of depressive symptoms. They performed a 12-week longitudinal study to explore prefrontal hemodynamic changes measured at 4-week intervals after starting sertraline treatment. The individuals were naive to antidepressant treatment with sertraline, and they used a 52-channel NIRS. From March 2012 through December 2016 individuals were recruited (n=11). The NIRS scans and clinical evaluation were conducted at 4 points: baseline or before starting the treatment, and 4, 8, and 12 weeks after starting the treatment. Sertraline dose was 25 mg/day.
Depressive symptoms improved after starting sertraline treatment (F₍₃,₈₎=11.67, P <.003), and at 12 weeks, the 11 participants achieved at least partial remission based on Diagnostic and Statistical Manual of Mental Disorders Fourth Edition criteria. During the 12-week observation period, the intra-class correlation coefficient of oxygenated hemoglobin values (oxy-HB) was moderate at the spatially and temporally contiguous cluster located in the left inferior frontal and temporal gyri. At 4 weeks, there was a significant negative correlation between mean oxy-HB values in the significant cluster. Changes in Hamilton Rating Scale for Depression total score were seen from 4 to 8 weeks (r=−0.73, P =.011), and from 4 to 12 weeks (r=−0.63, P =.039). The left prefrontal and temporal cortices showed persistent functional abnormality both before and after sertraline treatment; this might be a trait marker that represents neurobiological vulnerability for depression.
The limitations in this study are the small sample of individuals studied, and the lack of healthy control individuals to evaluate if the improvement of oxy-Hb activation after MDD treatment returned to normal levels or not.
The investigators of the study concluded that the ability to perform NIRS scans at an interval of 4 weeks provided a more detailed time course of oxy-HB alterations in the prefrontal and temporal regions in relation to sertraline treatment. NIRS signal 4 weeks after starting MDD treatment holds value as a biological marker to predict an individual’s response to treatment. Therefore, NIRS has potential use for capturing the details of functional alteration in the brain, along with clinical symptoms improvements in major psychiatric conditions.
Please see the original reference for a full list of authors’ disclosures.
Yamagata B, Yamanaka K, Takei Y, et al. Brain functional alterations observed 4-weekly in major depressive disorder following antidepressant treatment [published online April 3, 2019]. J Affect Disord. doi: 10.1016/j.jad.2019.04.001