Autonomic Nervous System Changes in Individuals with Anxiety And Depression Across the Lifespan: A Systematic Review

BACKGROUND AND AIMS: As a measure of systemic health, heart rate variability (HRV) can strongly and independently predict adverse future prognosis.1–3 Reduced HRV has been correlated to numerous chronic conditions such as cardiovascular disease and chronic pain.4 Evidence suggests that psychiatric disorders can have similar systemic effects.5 Anxiety and depression are two of the most common psychiatric disorders in the world.6 The primary aim of this systematic review is to determine the relationship between anxiety and/or depression and heart rate variability across the age spectrum. METHODS: Online databases including PubMed, Google Scholar, Ovid, and CINAHL were searched for papers dated 2004 through 2019. The search terms “anxiety,” “generalized anxiety disorder,” “depression,” and “major depressive disorder” were each paired with HRV. Search initially included were randomized control trials (RCTs) but due to availability of systematic reviews and metanalyses, RCTs were later excluded. Review protocol was preregistered though PROSPERO. RESULTS: Ten articles were included (7 depression, 3 anxiety).5,7–15 Both separately and together, anxiety and depression are correlated to diminished HRV. This is primarily demonstrated as a reduction in high frequency (HF) power and low HF/low frequency (LF) ratio, and inconsistently through a reduction in LF power. The most significant reduction in HRV was demonstrated in those with anxiety comorbid with heart disease. CONCLUSIONS: These findings suggest that psychiatric disorders including anxiety and depression can have a deleterious effect on the autonomic nervous system, resulting in decreased HRV. Earlier detection of these systemic changes may allow institution of interventions to restore healthy ANS function, perhaps preventing progression of systemic disease. STUDY SELECTION: Search pairs were issued to each researcher for independent initial search. Final included papers were then reviewed by two additional researchers for eligibility. Search initially included were randomized control trials (RCTs) but due to availability of systematic reviews and metanalyses of discrete populations, RCTs were later excluded. DATA EXTRACTION: Eligible papers were independently assessed for quality but two researchers using the NIH Quality Assessment Tool, with scores ranging from three to nine. Independent extraction of: number of included studies, subject characteristics, method of HRV collection, and conclusions was performed by two researchers. OBJECTIVES: Upon completion, participant will be able to describe the relationship between anxiety and depression and heart rate variability. Upon completion, participant will be able to list the changes in heart rate variability that can occur in individuals with anxiety or depression. Upon completion, participant will be able to describe the importance of heart rate variability in a wholistic intervention plan for individuals with anxiety or depression