BDNF blood levels as a potential biomarker Predictor of treatment response and remission in bipolar depression

Background

Immune dysfunction and inflammation play critical roles in the pathophysiology of bipolar disorder. Treatment-resistant bipolar depressive disorder (TRBDD) poses significant challenges in psychiatric practice, often unresponsive to standard treatment strategies. Celecoxib, a selective Cyclooxygenase-2 (COX-2) inhibitor, has shown promise as an add-on treatment for bipolar depression, potentially influencing brain-derived neurotrophic factor (BDNF) levels.

Methods

We assessed the effects of treatment on BDNF levels in 43 patients with Treatment-Resistant Bipolar Depressive Disorder (TRBDD), diagnosed with Bipolar Disorder I or II, and compared their baseline BDNF levels with those of 13 healthy control (HC) individuals. TRBDD participants were randomized to receive either Escitalopram plus Placebo (ESC + PBO) or Escitalopram with Celecoxib (ESC + CBX) for 8 weeks. BDNF levels in serum were measured at baseline, week 4, and week 8. The HC group only provided samples at baseline. Statistical analyses were conducted to compare BDNF levels between TRBDD and HC groups, as well as between TRBDD participants in the ESC + PBO and ESC + CBX groups, in relation to treatment response and remission.

Results

The TRBDD group demonstrated significantly lower baseline mean BDNF levels compared to the HC group (p = 0.015), suggesting a potential role for BDNF in the pathophysiology of TRBDD. However, BDNF levels at baseline, week 4, and week 8 did not differ significantly between responders and non-responders, or between remitters and non-remitters, within the TRBDD group, regardless of whether they were receiving ESC + PBO or ESC + CBX treatment.

Conclusions

The significant difference in baseline BDNF levels between TRBDD patients and healthy controls highlights the potential importance of BDNF in the pathophysiology of TRBDD. Our study suggests that Escitalopram with Celecoxib did not produce significant changes in BDNF levels over the study period. Further research with larger sample sizes and extended follow-up periods is necessary to explore the effects of these treatments on BDNF levels in TRBDD patients and to evaluate the use of BDNF levels as biomarkers for treatment response and remission.