A state of physical, emotional, and mental exhaustion caused by prolonged and excessive stress, characterized by emotional exhaustion, depersonalization/cynicism, and reduced personal accomplishment. Physiologically associated with HPA axis dysregulation and eventual hypocortisolism.
Burnout develops through progressive HPA axis exhaustion. Initial stage shows hyperactivation (elevated cortisol) with preserved stress response. Chronic activation leads to glucocorticoid receptor resistance in the HPA axis and immune system. Final stage involves adrenal exhaustion with blunted cortisol awakening response, flattened diurnal rhythm, and hypocortisolism. This coincides with elevated pro-inflammatory cytokines (due to loss of cortisol's anti-inflammatory effects), mitochondrial dysfunction, and prefrontal cortex dysfunction. Parasympathetic nervous system fails to recover adequately between stressors.
Burnout represents the endpoint of chronic stress where the organism can no longer maintain allostasis. Distinguished from depression by context-specificity (often work-related) and hypocortisolism (vs mixed cortisol patterns in depression). Treatment requires prolonged stress reduction (months), not just symptom management. Testing cortisol awakening response and diurnal rhythm guides treatment. Recovery requires metabolic support (mitochondria), inflammation reduction, and genuine lifestyle change—not pushing through.