Blood Test Predicts Effectiveness of Depression Medication

Depression and anxiety are two important mood disorders that are frequently associated with chronic diseases such as cardiovascular diseases (CVDs). Hyper-inflammation is related to both CVDs and psychological conditions such as depression and anxiety.

A finger-prick blood test could help doctors to choose which medication is most likely to succeed in treating depression as levels of C-reactive protein in the blood predict which antidepressant treatments are most likely to lead to successful outcomes in patients with depression.

Scientists at the University of Texas Southwestern Medical Center and their colleagues analyzed remission rates in 106 patients with depression who were randomly allocated between two groups. One group of 51 patients was prescribed the selective serotonin reuptake inhibitor escitalopram alone and 55 patients in the other group were prescribed escitalopram plus bupropion.

C-reactive protein (CRP), serum amyloid P component, and alpha-2-macroglobulin were measured using the Bioplex Pro human acute-phase 4-plex panel. The reason CRP was chosen was because it is often used as a marker of inflammation in cardiovascular disease, diabetes, and other disorders.

The team found that the treatment arms did not differ in depressive symptom or side effect outcomes. Most participants 74/106 (69.8%) had baseline CRP levels greater than 1 mg/L (indicative of systemic inflammatory activity). Higher baseline CRP levels were associated lower depression severity with bupropion-SSRI combination but not with SSRI monotherapy. The overall remission rate was 41.5%. The estimated remission rate with CRP threshold based assignment (SSRI monotherapy for less than 1 mg/L and Bupropion-SSRI for equal to or greater than 1 mg/L) was 53.1%. Side effect burden was unrelated to any baseline inflammatory marker.

Madhukar Trivedi, MD, a professor and senior author of the study, said, “Both patients and primary-care providers are very desperately looking for markers that would indicate there is some biology involved in this disease. Otherwise, we are talking about deciding treatments from question-and-answer from the patients, and that is not sufficient.” The study was published in the April 2017 edition of the journal Psychoneuroendocrinology.