Study on the Role of Inflammatory Markers and Type D Personality on Symptom Profiles and Severity in Patients with Major Depressive Disorder

The high rates of chronicity and recurrences account for the limited efficacy of current antidepressants, conceived based on the current neurobiological hypotheses, in reaching the full clinical and functional remission of major depressed (MDD) patients. We aimed to analyze the role of pro-inflammatory markers, C-reactive protein (CRP) and interleukin-6 (IL-6), respectively, and type D personality (TDP) on the depressive symptoms measured by the 17-item Hamilton Depression Rating Scale (HAM-D). The processed data are part of a prospective 8-weeks follow-up study conducted in 50 subjects with MDD referred to ‘Eduard Pamfil’ Psychiatric Clinic Timisoara. The presence of elevated pro-inflammatory markers in MDD patients with TDP has been significantly associated with higher somatic anxiety (p = 0.005) and somatic symptoms-general (p = 0.016) mean rank scores compared to their counterparts without significant inflammation. The combination of increased CRP and IL-6 levels were significantly correlated with higher impaired insight (p = 0.026) mean rank scores, additionally. The presence of a significant level of IL-6 has shown a significant effect of size (p = 0.023) on the severity of major depression at baseline. On the contrary, type D personality has not influenced the severity of depressive symptoms (p > 0.05). Inflammatory markers significantly impact the clinical profiles and symptoms severity of MDD patients.