Allostatic load in psychiatry - Systematic review and meta-analysis

Abstract

Stress exposure leads to the activation of multiple biological systems to maintain a dynamic equilibrium that has been termed “allostasis”. Prolonged and chronic activation of the allostatic systems exert a multi-system dysregulation termed the allostatic load (AL), the wear and tear on the body. The AL index is a measure of multisystem - cardiovascular, immune, neuroendocrine, and metabolic - biomarkers associated with toxic stress exposure. A systematic search strategy was conducted following the PRISMA guidelines. Twenty-two studies met our inclusion criteria and were included in this review, which all clearly described a mental health disorder (either psychotic or mood disorder) and used reliable and established measures to calculate the allostatic load index. Studies have consistently found an elevated allostatic load index in patients with psychotic disorders. Additionally, the elevated AL index is correlated with positive symptoms, symptom severity, worse treatment outcome, and an overall lower general and cognitive functioning. Our systematic review and meta-analysis have revealed that the AL index is increased in psychotic disorders but not in major depression.