ORLANDO — Elevated levels of cortisol in the hair of adult patients with schizophrenia or bipolar disorder (BD) indicate a history of childhood trauma and poorer cognitive performance, new research suggests.
In a study of more than 150 participants, those with schizophrenia or BD who reported a history of being abused or exposed to trauma in childhood showed significantly higher levels of cortisol in their hair vs healthy controls and in patients with no history of maltreatment.
In addition, patients experiencing a mood episode had higher hair cortisol levels than patients in remission. Higher hair cortisol was also associated with poorer cognitive performance, in particular working memory.
“We think that having childhood trauma experiences could produce long-term changes in the stress response. We know that childhood trauma is associated with chronic changes in the hypothalamic–pituitary axis, and that psychotic disorders are associated with dysregulation of that axis,” Aas said.
The investigators obtained hair samples from 63 participants with schizophrenia and/or BD and 94 healthy controls. Hair cortisol concentrations were measured by enzyme-linked immunosorbent assays, or ELISA.
A history of childhood maltreatment was assessed using the Childhood Trauma Questionnaire. Global function and symptom levels were obtained using the Global Assessment of Functioning Scale and the Positive and Negative Syndrome Scale.
Additionally, a standardized neuropsychologic test battery was performed to assess cognitive function.
Relative to the healthy controls group and patients without a history of childhood maltreatment, patients with a history of childhood trauma showed significantly higher levels of hair cortisol (P = .01).
In addition, patients experiencing a current mood or psychotic episode had higher hair cortisol levels than patients in remission (P = .03).
Finally, patients with higher cortisol concentrations had poorer cognitive performance scores, specifically in working memory (P = .01).
“The findings support the stress-diathesis model in schizophrenia and bipolar disorder first proposed in 1997 and updated in 2008, pointing to long-term changes in the HPA-axis following childhood maltreatment experiences,” Aas said. “Basically, high levels of stress are not good for our brain.”
Hair cortisol measurements are easy to obtain, and this makes it an ideal research tool, she noted.
“You don’t need a lot of hair, but it needs to be at least 2 cm. We take a sample from the back of the head, and it does not leave a gap or show at all. I didn’t see anything after I did it for the pilot study, and we have not had anyone complain about having a mark in their hair,” Aas said.
The hair sample is also very easy to store. It requires no refrigeration and can be wrapped in foil and kept at room temperature, away from direct sunlight, for months, she added.
Approached for comment by Medscape Medical News, Faith B. Dickerson, PhD, Sheppard Pratt Health System and Johns Hopkins Department of Psychiatry, Baltimore, Maryland, said that measuring cortisol in hair is “an accessible and non-invasive method.”
“The association between childhood maltreatment and the development of serious mental illness remains to be understood,” Dickerson noted. “This study points to one plausible mechanism.”
Aas and Dickerson have disclosed no relevant financial relationships.