Association between Heart Rate Variability Indices and Depressed Mood in Patients with Panic Disorder

OBJECTIVE: Heart rate variability (HRV) reflects the regulation of the autonomic nervous system. Panic disorder is highly associated with autonomic dysfunction, and is often accompanied by depression. The aim of this study is to determine the association between depression and HRV indices in patients with panic disorder. METHODS: A total of 110 outpatients diagnosed with panic disorder participated in this study. The medical records of patients with panic disorder who visited the outpatient clinic of Konkuk University Hospital between December 2018 and March 2020 were retrospectively reviewed. Measurements used in this study include the Panic Disorder Severity Scale-Self Report, Beck Depression Inventory (BDI-II), Insomnia Severity Index, and HRV. Patients were divided into depressive and non-depressive groups based on their BDI-II scores. The association between HRV indices and depressive symptoms was statistically analyzed. RESULTS: The low frequency/high frequency (LF/HF) ratio was reduced in patients with depression (mean = −0.095, p = 0.004 in the above moderate depressive group, mean = −0.120, p = 0.020 in the severe depressive group). Significant correlations were found between depressive symptoms and standard deviation of NN interval (SDNN) (ms) (−0.19, p = 0.044), very low frequency (VLF) (ms(2)/Hz) (−0.22, p = 0.021), LF (−0.25, p = 0.008), HF (−0.19, p = 0.043), and LF/HF (−0.25, p = 0.009). Multiple linear regression analysis showed that BDI predicted SDNN (ms), VLF (ms(2)/Hz), LF, HF, and LF/HF. CONCLUSION: We confirmed that the LF/HF ratio decreases when depression is accompanied by panic disorder. HRV indices may be useful markers for detecting depressive symptoms in patients with panic disorder.