Mitigation of stress: new treatment alternatives

Abstract

Complaints of stress are common in modern life. Psychological stress is a major cause of lifestyle-related issues, contributing to poor quality of life. Chronic stress impedes brain function, causing impairment of many executive functions, including working memory, decision making and attentional control. The current study sought to describe newly developed stress mitigation techniques, and their influence on autonomic and endocrine functions. The literature search revealed that the most frequently studied technique for stress mitigation was biofeedback (BFB). However, evidence suggests that neurofeedback (NFB) and noninvasive brain stimulation (NIBS) could potentially provide appropriate approaches. We found that recent studies of BFB methods have typically used measures of heart rate variability, respiration and skin conductance. In contrast, studies of NFB methods have typically utilized neurocomputation techniques employing electroencephalography, functional magnetic resonance imaging and near infrared spectroscopy. NIBS studies have typically utilized transcranial direct current stimulation methods. Mitigation of stress is a challenging but important research target for improving quality of life.

Keywords: Biofeedback; Neurofeedback; Noninvasive brain stimulation; Stress management.

Fig. 1

Brain areas exhibiting activation in response to stress. The sensory information is received from cortical areas ① and associated with memory-related information registered in the amygdala ② before proceeding to the hypothalamus ③. This information is transmitted to nerve endings in various parts of the body via the brain stem and reticular fibers that link the brain with the spinal cord. Responses are then transmitted via neuronal synapses to the sympathetic and parasympathetic branches of the autonomic nervous system (ANS) via the vasomotor center ④ located in the reticular area, as a rapid recovery method. The hypothalamus then initiates the secretion of hormones as an intermediate recovery method. Perceived stress causes the hypothalamus to stimulate the production of corticotrophin-releasing hormone (CRH) ⑥, which travels through blood vessels to reach pituitary gland and results in the secretion and release of adrenocorticotropic hormone (ACTH) ⑦. Upon secretion into the blood, ACTH sequentially activates the adrenal cortex. The adrenal cortex produces and releases glucocorticoids, particularly cortisol in humans

Fig. 2

Significantly increased gray matter volume in biofeedback group compared to non-intervention group. These areas include the right lateral orbitofrontal cortex and an anatomical region including the left hippocampus. Reproduced from Kotozaki et al. (2014)

Fig. 3

Pre- and post-treatment comparison of brainwaves, cortisol and DHEA-S. Reproduced from Burns (2015)