Heart rate variability, affective disorders and health

Abstract

Resting-state heart rate variability (HRV) may have important functional significance for social approach behaviour, emotion regulation and psychological flexibility in the face of stressors. It may also reflect the functioning of important physiological processes including vagal regulation over a variety of allostatic systems and multisystemic adaptations to maintain homeostasis. Research on the effects of the affective disorders on HRV therefore has important implications for the health and wellbeing of patients. Studies have demonstrated that HRV is reduced in otherwise healthy patients with these disorders, especially major depression and generalised anxiety disorder, and that the behavioural features of these disorders (e.g. smoking, physical inactivity) do not fully explain the observed HRV reductions. Vagal impairment may underpin many of the observed symptoms in affective disorders including flattened affect, attenuated facial expressions and lack of emotional prosody. It may also contribute to a pathophysiological 'wear and tear' effect on the body leading to increased morbidity and mortality. Health behaviours such as a healthy diet, physical exercise and even meditation may have an important role to play in appropriate psychiatric care of patients with affective disorders because these interventions facilitate increases in HRV, which reflect enhanced vagal function that may lead to subsequent improvements in mental and physical health. Further study is needed to determine whether simple health behaviours are able to ameliorate the reductions in HRV associated with use of antidepressant medications. Research is also needed on possible moderators and mediators of vagal impairment, and its improvement, in the affective disorders.