The objective of this work was to study circadian rhythms of the indicators of the spectral analysis of the heart rate variability in case of depression.
Materials and methods: A total of 37 patients, with a mean age of 46.7+/-10.3 years, were examined. According to the International Classification of Disease, 10th revision (ICD-10), endogenous depression was diagnosed for all of them (F 31.3-31.4, F 32.0-32.2, F 33.0-33.2). To assess the variability of the heart rhythm, the spectral analysis was used. The patients were examined at 1 AM, 7 AM, 1 PM, 7 PM prior to the beginning of treatment, following one week, and upon leaving the inpatient department. The control group consisted of 15 mentally healthy people.
Results: Before the beginning of treatment, desynchronization of circadian rhythms of the indicators studied and the sleep-wake cycle, the increase in the spectrum power within low-frequency (LF) range, and the decrease in the spectrum power within high-frequency (HF) range were observed. Reduction of depression symptoms was followed by resynchronization of the rhythms under study, with a spectrum power within LF range being increased and that within HF range--decreased.
Conclusions: Changes in depression symptoms and chronobiological disorders testify to their close pathogenetic link.