Biomarker May Predict Response to Antidepressants

Psychiatrists understand the frustration patients feel when they start an antidepressant, deal with the side effects, and do not experience any change in their symptoms for as many as six weeks, if they respond at all. But researchers may be one step closer to developing a simple blood test that could indicate whether a patient will respond to a prescribed antidepressant as early as one week after starting the medication.

A biomarker, short for "biological marker," is an objectively measurable biological characteristic that can be associated with a medical condition. A reliable biomarker can be invaluable when a disease presents with no externally measurable objective symptoms.