If old memories, buried grief, or feelings you thought you had dealt with are flooding back in perimenopause, this is not a breakdown. Estrogen directly regulates the amygdala — the brain's fear centre — and supports the prefrontal cortex's ability to suppress threatening memories. As it fluctuates and falls, your brain's buffer weakens, your window of tolerance narrows, and trauma that was held in place by hormonal stability can surface. The science explains why. What helps