Abstract
BACKGROUND: Older adults are vulnerable to comorbid depression and anxiety symptoms; however, these conditions are widely underrecognized and often untreated. Understanding their combined manifestation using objective measurements, such as clinician-rated scales and heart rate variability (HRV), can help refine the diagnosis and select a treatment strategy for geriatric patients. METHODS: This study included patients over 65 years who were mainly diagnosed with either category of depressive or anxiety disorders from the psychiatric outpatient clinic in a university hospital. A total of 114 patients met eligibility with a completed collection of electrocardiograms, the Hamilton Depression Rating Scale (HDRS; clinician-rated depression), and the Hamilton Anxiety Scale (HAS; clinician-rated anxiety) to assess the severity of symptoms. Both main and interaction effects between HDRS and HAS on HRV parameters were examined. RESULTS: Significant interaction effects between clinician-rated depression and anxiety (HDRS × HAS) on HRV reduction in frequency parameters (i.e., nuLF, nuHF, LF/HF ratio) were found, which consistently indicated autonomic nervous system dysregulation. Findings imply that HRV could reflect synergistic effects of comorbid depressive and anxiety symptoms, perhaps due to the amplification of individual symptoms in geriatric patients. CONCLUSIONS: The results imply that using objective measurements can improve diagnostic accuracy, particularly in geriatric patients with comorbid status, and the normalization of the autonomic nervous system might be a candidate target for prevention and treatment.