Heart rate variability and allostasis in individuals with depression and anxiety symptoms

Allostasis suggests that variation in an organism's physiological response to the environment optimizes functioning and balance, and when this variation is non-existent or impaired it can lead to negative health outcomes. Experiencing chronic negative emotion can impair this process, causing a "wear and tear" in the physical system. Anxiety and depression are both related to the experience of chronic negative emotion. It is believed that worry plays a role in anxiety by blunting emotional experience through hyper-arousal. This causes the system's allostatic process to become impaired, something known as allostatic load. In depression, it is believed that a person will over-react to sad emotion due to its congruence to the disorder. Through heart rate variability as a measure of autonomic flexibility (how well the autonomic system responds to environmental changes), this study aims to investigate the effects of depressive and anxious symptoms on allostasis, through the use of emotion films.