Hair cortisol analysis as a marker of past adverse experiences in adult patients with severe mental illness

Abstract

Both altered hypothalamic–pituitary–adrenal (HPA) axis activity and the exposure to adverse childhood experiences (ACE) have been repetitively documented in mental illness. Recent studies describe the impact of past environmental stress on hair cortisol using dose-dependent models: with increasing number of traumatic experiences, lower, but also higher hair cortisol levels have been observed. Besides the dose-dependent effect, recent evidence indicates a distinctive impact of type and timing of ACE on the developing organism, supporting the notion of stress-sensitive periods in (brain) development. The specific contribution of types and timings of adversities needs further evaluation for the alternations of HPA axis. The presented study evaluates the impact of childhood adversities on hair cortisol in patients with severe mental illness. Novel aspects were a detailed screening of various intrafamilial and peer-related types of adversities together with their timing in childhood and adolescence (using the retrospective assessment with the Maltreatment and Abuse Chronology of Exposure, MACE Scale), as well as a fine-grained analysis of predictive modeling of hair cortisol levels using conditioned forest regression.