Diagnostic and Predictive Utility of Plasma Phosphoethanolamine Levels in Depressive Disorder: A Naturalistic Observational Study.

OBJECTIVES

Plasma phosphoethanolamine (PEA) has been proposed as a potential biomarker for depressive disorder. To further assess its diagnostic utility and relevance across psychiatric conditions, we conducted a larger observational study in a psychiatric primary care setting.

METHODS

Between 2013 and 2020, 576 patients underwent DSM-5-based psychiatric assessments. Plasma PEA levels were measured in 295 patients with depressive disorders, 264 with other psychiatric disorders, and 17 with physical illnesses.

RESULTS

PEA demonstrated moderate or high diagnostic accuracy for depressive disorder (AUC = 0.81, 95% CI: 0.78-0.85). Lower PEA levels were significantly associated with depression (OR = 16.30, p < 0.001).

CONCLUSIONS

These findings suggest that plasma PEA concentration may serve as a useful biomarker for depressive disorder. Further studies are warranted to explore its potential relationship with white matter pathology in psychiatric conditions.