Effects of heat environments on depressive disorders: Neurogenesis-mediated mechanisms.
Level 5 - mechanism / opinion, no new human data
Narrative review of biological mechanisms without original human trial data
PubMed 41205362 · doi:10.1016/j.jtherbio.2025.104304
What was done
This narrative review synthesizes proposed biological mechanisms linking environmental heat exposure to depressive disorders, focusing on hypothalamic-pituitary-adrenal (HPA) axis activation, glucocorticoid signaling, brain-derived neurotrophic factor (BDNF) expression, and hippocampal neurogenesis.
What was found
The abstract provides no empirical numbers or quantitative findings. It outlines a mechanistic pathway wherein heat stress activates the HPA axis to increase glucocorticoids, downregulate BDNF, impair synaptic plasticity and neurogenesis, and induce heat shock protein overexpression that disrupts BDNF-TrkB-PI3K/AKT signaling.
Why it matters
It provides a structured biological framework for understanding how ambient thermal stress may contribute to the pathophysiology of depressive disorders.
Limits
The review contains no new clinical or experimental data, reports no quantitative effect sizes in the abstract, and does not state the number of studies evaluated. The proposed mechanisms are largely theoretical and preclinical.
Cited by
- context Heat exposure and sauna bathing stimulate the production of brain-derived neurotrophic factor (BDNF), promoting neurogenesis and neuroplasticity.