An Experience-Sampling Approach to Examining Cortisol and Testosterone Profiles in Bipolar and Depressive Mood Disorders
Objectives: Emotion dysregulation is a core component of bipolar disorder (BD). However, there is a critical gap concerning the measurement of emotion-relevant neuroendocrine processes in this population. Methods: The present investigation examined neuroendocrine profiles (i.e., cortisol and testosterone) alongside emotional experiences across three consecutive days in naturalistic settings among adults with bipolar I disorder (n = 28) compared to a clinical comparison group of adults with a history of major depressive disorder (MDD; n = 28) and healthy non-psychiatric controls (n = 27). Results: The BD group exhibited decreased cortisol concentrations throughout the day, lower overall hormone output, and smaller awakening responses when compared to MDD, and flatter slopes compared to both MDD and control groups. The BD group did not differ from either group in any diurnal testosterone measures. Groups did not differ in mean positive and negative daily emotion ratings, but the BD group reported greater positive and negative variability, and the MDD group greater NA variability, than the control group. Conclusions: Despite similar emotion experiences during daily living, participants with BD exhibited decreased cortisol slopes relative to those with depression and controls. Cortisol levels across all measures in MDD were comparable to controls. Findings suggest the link between cortisol and mood is complex, and decreased cortisol profiles may be a marker of bipolar mood disorders.