Association of clinical features and biomarkers with treatment-resistant depression

Background

Treatment-resistant depression (TRD) is associated with inflammatory biomarkers, childhood maltreatment, suicidal behaviour and functional impairment.

Methods

Our sample was divided in 3 groups. TRD group was considered with a 17-item Hamilton Depression Rating Scale (HDRS₁₇) for depression score remaining greater to 16 after 2 consecutive adequate treatment for bipolar disorder (BD) or major depressive disorder (MDD) (n = 24), non-TRD (n = 120) group and controls (n = 82). Socio-demographic and clinical data were assessed by structured questionnaire. Other assessments used were body mass index (BMI), Sheehan Disability Scale and Childhood Trauma Questionnaire. Laboratory biomarkers were leptin and high-sensitivity C-reactive protein (hs-CRP).

Results

The clinical features associated with TDR group were earlier at onset of first episode, increased number of depressive episodes, higher lifetime suicide attempts and comorbidities with panic disorder and PTSD. TRD group was more likely to have disability for work (OR = 8.20) and underproductive days (OR = 1.09) than non-TRD and control groups. Higher levels of leptin, hs-CRP > 3 mg/L and higher BMI were also found to be associated with TRD. The TRD patients with hs-CRP > 3 mg/L presented on average higher levels of leptin for the same BMI, compared to non-TRD.

Limitation

Retrospective assessment to investigate child abuse could be based on recall bias.

Conclusions

These findings suggest TRD is associated with earlier onset age, more depressive episodes and suicide attempts, comorbidities and functional impairment. TRD patients also should be assessed to comorbidities, childhood sexual abuse and increased levels of CRP and leptin.