Stress reduction correlates with structural changes in the amygdala

TLDR

Stress adversely affects health, the amygdala is key in stress responses, but gray‑matter changes linked to stress have been inconsistently reported. The study aimed to examine how reductions in perceived stress during an 8‑week mindfulness‑based stress‑reduction program relate to changes in amygdala gray‑matter density. Twenty‑six healthy adults underwent the intervention, completed the Perceived Stress Scale, and had anatomical MRIs before and after, with PSS change used as a predictor of gray‑matter density changes in the bilateral amygdala. Participants showed significant stress reductions, and these reductions correlated with decreased gray‑matter density in the right basolateral amygdala, indicating that psychological improvement is linked to neuroplastic changes.

Abstract

Stress has significant adverse effects on health and is a risk factor for many illnesses. Neurobiological studies have implicated the amygdala as a brain structure crucial in stress responses. Whereas hyperactive amygdala function is often observed during stress conditions, cross-sectional reports of differences in gray matter structure have been less consistent. We conducted a longitudinal MRI study to investigate the relationship between changes in perceived stress with changes in amygdala gray matter density following a stress-reduction intervention. Stressed but otherwise healthy individuals (N = 26) participated in an 8-week mindfulness-based stress reduction intervention. Perceived stress was rated on the perceived stress scale (PSS) and anatomical MR images were acquired pre- and post-intervention. PSS change was used as the predictive regressor for changes in gray matter density within the bilateral amygdalae. Following the intervention, participants reported significantly reduced perceived stress. Reductions in perceived stress correlated positively with decreases in right basolateral amygdala gray matter density. Whereas prior studies found gray matter modifications resulting from acquisition of abstract information, motor and language skills, this study demonstrates that neuroplastic changes are associated with improvements in a psychological state variable.