Use of heart rate variability infographies in identification of depression status complementing the Patient Health Questionnaire-9

Depression is a strong risk factor for chronic illness. It also increases the risk of morbidity and mortality associated with cardiovascular disease (CVD). Heart Rate Variability (HRV) analysis, which characterizes cardiovascular health and depression status can provide information on any pathophysiological effect of depression on CVD and also effect of CVD on depression. HRV measures provide additional information to the physician to improve the management of depression and prevent CVD-associated mortality. In this study time and frequency domain HRV measures were investigated for 67 cases with different levels of depression classified according to the Patient Health Questionnaire (PHQ-9). A new four-level depression range of PHQ-9 scores was then obtained by systematically modifying the standard ranges, to achieve the highest statistical HRV difference between the categories. In order to assist the assessment of depression, its progression and associated cardiovascular condition, an illustrative circular mapping of HRV measures was developed. This HRV infographic shows the normal range of HRV measures, and provides a simple graphical illustration for identifying abnormal HRV and stage of depression based on the modified PHQ-9 scale.