Results from the BRITE-MD (Rapid Identification of Treatment Effectiveness in Major Depression) study suggest that the use of frontal quantitative EEG (fqEEG) could be used as a biomarker to predict treatment outcome with the antidepressant escitalopram (ESC).

In this open-label study of adults with DSM-IV-defined major depressive disorder, all subjects initially received ESC (10 mg/day) for a period of one week. Subjects were then randomized to either: 1) continued treatment with ESC; 2) bupropion XL (BUP; 300 mg/day); or 3) augmentation of ESC with BUP, for an additional 7 weeks (n=220). Subjects were assessed for severity of depression using the HAM-D-17 instrument, as well as 4-channel fqEEG. Study endpoints were Response (≥50% decline in HAM-D) and Remission (final HAM-D =7).

The predictive metric that was used in the study consisted of a composite EEG index—the Antidepressant Treatment Response (ATR)—which was developed to predict clinical response using fqEEG from baseline to Week 1.

Results at 7 weeks showed that the response rates for those patients who remained on the ESC initial treatment was higher for ATR-predicted responders than for ATR-predicted non-responders (68% vs 28%; p=0.001). This predictive ability also was seen amongst ESC patients who achieved remission, wherein ATR-predicted remitters occurred at a higher rate than the ATR-predicted non-remitters (50% vs 21%; p=0.01). For patients who were identified as ATR-predicted non-responders at one week and then randomized to BUP, a higher response rate was achieved as compared with those who remained on ESC (53% vs 28%; p=0.034). ATR-predicted non-responders who received BUP augmentation had a numerically higher response rate than those who remained on ESC for the entire study period (33% vs 28%); however, these results were not significant.

Though not yet definitive, the findings of BRITE-MD suggest that an ATR index at Week 1 of ESC treatment may help guide antidepressant selection, potentially leading to improved outcomes of antidepressant therapy.

For additional information, please visit: www.BRITE-MD.org.