Childhood maltreatment was found to be a predictor for development of schizophrenia (SZ) and bipolar disorder (BD) in a study conducted to understand the possible mechanisms associated with the disease development.1 Elevated cortisol levels in the hair of adult patients were the evidence of childhood abuse or neglect, which was confirmed by a self-administered questionnaire.1 The findings of the study were presented at the annual congress of the Schizophrenia International Research Society (SIRS) 2019, Orlando, Florida, USA, and subsequently published in the Journal of Schizophrenia Research.1,2
Chronic traumatic stress is already a defined factor in the development of SZ and BD.3 Yet, the biological mechanism of stress affecting severe mental disorders remains unclear. Cortisol level is an indicator of the hypothalamic-pituitary-adrenal (HPA) axis, which controls the body’s reaction to stress.4 Although cortisol levels can be detected in blood, urine or saliva, these sources are not a reliable measure of chronic stress.5 Using human hair to measure long term cortisol levels, however, has emerged as a reliable and valid estimate.6
The investigators obtained hair samples from 63 participants with SZ or BD and 94 healthy controls. Hair cortisol concentrations were measured by enzyme-linked immunosorbent assays.1 A history of childhood maltreatment constituting all forms of child abuse was assessed using a validated self-administered childhood trauma questionnaire.1 Additionally, a standardized neuropsychologic test was performed to assess the cognitive function.
In the study, more than 150 participants with SZ or BD reported a history of being abused or exposed to trauma in childhood. Concurrently, these individuals showed significantly higher levels of cortisol in their hair compared to healthy controls or individuals with no history of maltreatment (p=0.01).
“Hair cortisol is a marker of stress over time,” said, the lead investigator of the study, Dr. Monica Aas, Oslo University Hospital and University of Oslo, Norway.2 She further explained the findings stating, “We think that childhood trauma experiences could produce long-term changes in the stress response. We know that childhood trauma is associated with chronic changes in the HPA-axis, and that psychotic disorders are associated with dysregulation of that axis”.2
Moreover, SZ or BD patients who were undergoing a current mood or psychotic episode had higher hair cortisol levels than patients in remission (p=0.03). According to the study, higher cortisol concentrations are linked to poorer cognitive performance scores, particularly working memory (p=0.01).1
In view of the findings, Dr. Aas mentioned “The finding supports that long-term changes in HPA-axis are associated with SZ and BD following childhood maltreatment experiences. Basically, high levels of stress for longer durations are not good for our brain”.2
Faith B. Dickerson, PhD, Sheppard Pratt Health System and Johns Hopkins Department of Psychiatry, Baltimore, Maryland, said “The association between childhood maltreatment and the development of serious mental illness remains to be understood. This study points to one plausible mechanism”.2 Furthermore, Dr Dickerson suggested that measuring cortisol in hair is “as an accessible and non-invasive method”.2
In conclusion, the cortisol levels in human hair is an indication of long-term changes in the HPA-axis, and inadvertently the level of chronic stress. It was shown that higher levels of cortisol were associated with childhood maltreatment experiences in patients with SZ or BD. Further research is warranted in the utilization of hair cortisol levels as a predictor of severe mental disorders.
1. Aas M, Pizzagalli DA, Laskemoen JF et al. Elevated hair cortisol is associated with childhood maltreatment and cognitive impairment in schizophrenia and in bipolar disorders. Schizophr Res. 2019. [Epub ahead of print]
2. High Cortisol in Hair Indicates Child Trauma, Poor Cognition. Medspace.com. (Accessed May 27, 2019 at, https://www.medscape.com/viewarticle/911917).
3. Mayo D, Bolden KA, Simon TJ et al. Bullying and psychosis: The impact of chronic traumatic stress on psychosis risk in 22q11.2 deletion syndrome – a uniquely vulnerable population. J Psychiatr Res. 2019;114:99-104.
4. Mondelli V, Dazzan P, Hepgul N et al. Abnormal cortisol levels during the day and cortisol awakening response in first-episode psychosis: The role of stress and of antipsychotic treatment. Schizophr Res. 2010;116(2-3):234-42.
5. Stalder T, Kirschbaum C. Analysis of cortisol in hair-state of the art and future directions. Brain Behav Immun. 2012;26(7):1019-1029.
6. Stalder T, Steudte-Schmiedgen S, Alexander N et al. Stress-related and basic determinants of hair cortisol in humans: A meta-analysis. Psychoneuroendocrinology. 2017;77:261-274.