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The following is a summary of “Bipolar disorder at mixed states and major depressive disorder with mixed features differ in peripheral biochemical parameters,” published in the April 2025 issue of BMC Psychiatry by Wu et al. 

Limited data exist on peripheral biochemical differences between bipolar disorder at mixed episodes (BDM) and major depressive disorder with mixed features (MDM). 

Researchers conducted a retrospective study to compare peripheral biochemical parameters in patients with BDM and MDM.  

They included data from 269 patients with BDM and 86 MDM. Biochemical markers related to immune-inflammatory, liver function, metabolic, and thyroid hormone indices were analyzed. They used logistic regression, network analysis, and principal component analysis (PCA) to assess associations and relationships among parameters. 

The results showed that patients with BDM had higher neutrophil percentage (NEUT%), white blood cell count (WBC), free triiodothyronine (FT3) and free thyroxine (FT4), while patients with MDM had higher C-reactive protein (CRP), direct bilirubin (DBIL) and prealbumin (PA). NEUT%, WBC, FT3, and FT4 were positively associated with BDM; PA and DBIL were negatively associated. No significant differences in network structure or global strength were found. 

Investigators found that peripheral biochemical markers, especially immune-inflammatory factors and thyroid hormones, differed between BDM and MDM. They suggested these differences may help understand the underlying mechanisms of the disorders. 

Source: bmcpsychiatry.biomedcentral.com/articles/10.1186/s12888-025-06800-9