Abstract
【Background】 To dynamically monitor the plasma melatonin and cortisol levels in patients with bipolar depressive episodes, to improve polysomnography, and to analyze the circadian rhythm characteristics of patients with bipolar depression, we explore the value of circadian rhythm disorders diagnosed bipolar depression.【Methods】A total of 54 subjects were included, comprising 16 cases of bipolar depression, 12 cases of unipolar depression, 11 cases of bipolar depression in remission, and 15 healthy controls. High-performance liquid chromatography-tandem mass spectrometry was used to detect the plasma melatonin and cortisol levels of the four groups at 8 am, 12 am, 4 pm, 8 pm, and polysomnography were determined.
【Results】 The plasma melatonin levels at 8 am in the bipolar depression group were higher than those in the unipolar depression group at 8 am(mean difference = 22.504, t = 2.833, P = 0.014), but the plasma melatonin levels at 8pm were lower than those in the unipolar depression group at 8pm(mean difference = -2.471, t = -2.506, P = 0.006). And the plasma cortisol levels in the bipolar depressive episode group at 8 am (mean difference = 57.411, t = 2.623, P = 0.001), 12 pm (mean difference = 39.276, t = 2.879, P < 0.001), and 8 pm (mean difference = 62.692, t = 2.697, P = 0.001) were higher than those in the unipolar depression group at the same time.
【Conclusion】Patients with bipolar depression have a dysregulation of plasma melatonin and cortisol levels, with circadian rhythm disturbances, and these disturbances may contribute to the diagnosis of bipolar depression.