The role of cortisol, C-reactive protein and brain-derived neurotrophic factor in predicting anxiety, depression and mood swings: a cross-sectional study

Objective: To evaluate the role of serum biomarkers—Cortisol, C-reactive protein (CRP), and brain-derived neurotrophic factor (BDNF)—to predict severity of mental health conditions like anxiety, depression, and mood disturbances. Material and Methods: A cross-sectional study was conducted at Liaquat University of Medical and Health Sciences (LUMHS), Jamshoro, from February 2024 to September 2024, involving 283 participants. Mental health symptoms were assessed using standardized scales, including the Generalized Anxiety Disorder-7 (GAD-7) for anxiety, the Patient Health Questionnaire-9 (PHQ-9) for depression, the Mood Disorder Questionnaire (MDQ) for mood swings, and the Perceived Stress Scale (PSS) for stress evaluation. Biomarker analysis involved measuring salivary cortisol levels (morning, afternoon, and evening samples) and serum concentrations of C-reactive protein (CRP) and brain-derived neurotrophic factor (BDNF). Data were analyzed using Pearson’s correlation and one-way ANOVA with Tukey’s post hoc comparisons. Results: Morning cortisol levels were significantly associated with anxiety (p < 0.001), while CRP exhibited a strong correlation with depression severity (r = 0.85, p < 0.001). Participants with severe mood swings had significantly lower BDNF levels compared to those with mild or moderate symptoms (p < 0.01). No significant correlations were found between afternoon or evening cortisol and anxiety or between BDNF and depression. Conclusion: The findings suggest that elevated morning cortisol, high CRP, and low BDNF are potential biomarkers for predicting anxiety, depression, and mood swings, respectively. These biomarkers could aid in mental health diagnostics and personalized treatment approaches. Keywords: Cortisol, C-reactive protein (CRP), Brain-derived neurotrophic factor (BDNF), anxiety, Depression, Mood swings, Biomarkers, Mental health