Hair Cortisol as a Biomarker for Mood in Bipolar Disorder: A Pilot Study

In a pilot study involving 38 participants with bipolar disorder (BD), researchers investigated the potential of hair cortisol as a biomarker for mood states in BD. They measured cortisol levels in 2 cm hair segments, which reflect two months of hair growth, and assessed mood using the Hamilton Depression Rating Scale (HDRS), Beck Depression Inventory (BDI), and Hamilton Anxiety Rating Scale (HAM-A). After accounting for age, gender, family status, education, and medication, they found a positive correlation between hair cortisol levels and mood scores across all three scales (r = 0.45–0.55, p <= 0.01). The study concludes that hair cortisol is a promising biomarker for reflecting the mood of BD patients over recent months.