Baseline C-reactive protein (CRP) levels appear to act as a biomarker of individual response to selective serotonin reuptake inhibitors (SSRIs) in persons with major depressive disorder.
In a study of more than 100 patients with depression, serum levels of CRP predicted response to escitalopram monotherapy or escitalopram plus bupropion. Low baseline CRP concentrations were associated with greater reductions in depression severity with monotherapy, while participants with higher levels had a better response to the combination treatment. For patients with CRP <1mg/l, 57 per cent achieved remission with monotherapy compared to less than 30 per cent on combination therapy. In contrast, among those with CRP ≥1mg/l, half responded to escitalopram plus bupropion compared to a third with escitalopram alone.
The findings, presented in the journal Psychoneuroendocrinology , could put an end to the trial-and-error approach to selecting antidepressant medication. “Currently, our selection of depression medications is not any more superior than flipping a coin, and yet that is what we do. Now we have a biological explanation to guide treatment of depression,” said lead author Dr. Madhukar Trivedi. Moreover, because CRP can be determined from a simple finger-prick test, Dr. Trivedi pointed out that the findings can easily be translated to clinical practice.