Childhood Trauma Linked to Increased Risk for Chronic Fatigue Syndrome

Caroline Cassels

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January 9, 2009 — Childhood trauma has been linked to a significantly increased risk for chronic fatigue syndrome (CFS) in adulthood, new research suggests.

A study by investigators at Emory University School of Medicine, in Atlanta, Georgia, shows that exposure to childhood trauma, including sexual, physical, and emotional abuse as well as emotional and physical neglect, is associated with more than a 5-fold increased risk for the condition, which is estimated to affect up to 2.5% of the US adult population, at an annual cost of about $9.1 billion.

Investigators also found that adults with CFS who report abuse have decreased levels of the stress hormone cortisol, a finding that suggests a potential biological mechanism for the disease.

"This study replicates our previous preliminary findings, that childhood trauma is a very important risk factor for CFS, particularly emotional maltreatment and sexual abuse. Further, it suggests there is a biological correlate (low cortisol levels), which further supports the hypothesis that childhood trauma alters the body's stress hormone system and its subsequent ability to adapt to stress," principal investigator Christine M. Heim, PhD, told Medscape Psychiatry.

The study is published in the January issue of the Archives of General Psychiatry.

Low Cortisol a Hallmark Feature

Preliminary results from a previous study conducted by Dr. Heim in a cohort from Wichita, Kansas, indicate that there is an association between CFS and early trauma. In addition, other research in animals and humans has shown that early life experience can program the development of regulatory systems implicated in CFS, including the hypothalamic-pituitary-adrenal (HPA) axis.

The adrenal gland synthesizes and secretes glucocorticoids in response to stress, which help regulate metabolic, behavioral, and immune systems. However, research suggests that insufficient glucocorticoid signaling may increase immune activation and inflammatory responses, which may then plausibly contribute to symptoms of fatigue and pain.

Interestingly, the authors point out that dysfunction of the HPA axis, characterized by lower-than-normal cortisol secretion, is 1 of the hallmark biological features of CFS.

To replicate their previous findings and further explore the potential relationship between childhood trauma and neuroendocrine dysfunction in CFS, the investigators, in collaboration with the Centers for Disease Control and Prevention, conducted a population-based study that included 113 individuals with CFS and 124 healthy matched controls.

Participants were identified from a general sample of 19,381 adult residents of Georgia and reported whether they had experienced childhood trauma, including sexual, physical, and emotional abuse or emotional or physical neglect.

Subjects were also screened for depression, anxiety, and posttraumatic stress disorder. Cortisol levels were also assessed using saliva testing that was conducted immediately after subjects awoke in the morning. This is because cortisol secretion follows a distinct circadian pattern, with a steep increase occurring within the first 30 minutes after wakening and lower levels in the evening.

Different CFS Subtypes?

The researchers found that individuals with CFS had significantly higher overall childhood trauma scores than controls in each trauma category.

Any type of childhood trauma was associated with a 5.6-fold increased risk for CFS. However, sexual abuse and emotional abuse and neglect were the most predictive of CFS. In addition CFS cases who had comorbid PTSD had a 9-fold increased risk, which Dr. Heim described as a "very large odds ratio for this type of research."

Overall cortisol levels were lower in CFS patients than levels in healthy controls — a finding that is consistent with previous research. Interestingly, however, when researchers looked at CFS cases with and without childhood adversity separately, individuals with CFS who did not report childhood abuse or neglect had similar cortisol levels to controls, a finding that suggests there may be different subtypes of the disorder.

"It is possible that different factors could contribute to the same illness, and changes in biological stress systems are seen only in those who also develop the illness in relation to emotional abuse or neglect, while in other individuals the disease has an entirely different pathophysiology. However, at this point this is just speculation and something that requires further investigation," said Dr. Heim.

Based on these findings, said Dr. Heim, it would be prudent for clinicians who have patients with CFS to screen for childhood trauma and, if the screen is positive, consider psychological referral.