Antidepressant therapy and C-reactive protein levels

Major depression is associated with activation of the inflammatory response.

To examine C-reactive protein levels in depression and to determine the impact of selective serotonin reuptake inhibitor (SSRI) therapy.

A two-part study. In study 1, which used a between-subjects design, C-reactive protein was measured in 32 patients (20 currently depressed, 12 euthymic) with a history of DSM-IV major depression, all of whom were treated with an SSRI, and in a healthy comparison group (n = 20). Study 2 employed a within-subject design: C-reactive protein was measured in 20 patients with major depression both before and after SSRI treatment.

In study 1, C-reactive protein levels did not differ between the group with depressive disorder (either currently depressed or euthymic) treated with SSRIs and the healthy group. In study 2 the protein levels dropped significantly following treatment with antidepressant medication.

Following SSRI treatment for major depression there is a significant drop in C-reactive protein concentrations whether or not the depression resolves. These findings indicate that antidepressants induce an anti-inflammatory response independent of antidepressant action.