The findings from this study fit with what we know about trauma and MS, says Dina Jacobs, MD, the clinical director of the multiple sclerosis and related disorders center at Penn Medicine in Philadelphia, who was not involved in the research. “The release of stress hormones chronically may impact the immune system, and it is certainly plausible that chronic stress may have an impact here,” says Dr. Jacobs, adding that although the research found an association, it doesn’t prove that the trauma directly caused any of the women to develop MS.
Evidence That Stress and Trauma Could Influence Autoimmune Disorders, Including MS
A study published in JAMA in 2018 that included more than one million people found an association between exposure to trauma and stressful life events and an increased risk of autoimmune disorders. Stressful events in adult life, such as the loss of a loved one, divorce, or personal conflict, has been linked to an increased likelihood a person will develop MS, in a 2020 study published in the European Journal of Neurology. Researchers designed the new study to further explore how childhood trauma might impact the risk of MS developing later in life.
Childhood Sexual Abuse Had Strongest Association With Later MS
The study included a total of 77,997 pregnant women who were enrolled in the Norwegian Mother, Father, and Child cohort study. Participants were recruited between 1999 and 2008, and their health was monitored until the end of 2018. Information on childhood abuse before age 18 was gathered through responses to questions about whether or not participants had been subject to humiliation, threats, or physical or sexual abuse. Confirmation of MS diagnoses was obtained from linked national health registry data and hospital records. A total of 14,477 women reported experiencing childhood abuse, while 63,520 said they had not. Researchers found that women with a history of abuse were more likely to be current or former smokers — a known risk factor for MS, and to have overweight, as well as depressive symptoms. The women were followed for at least 10 years, with an average follow-up of 13 years; during that period, 300 women were diagnosed with MS. Key findings included:
Of the women who were diagnosed with MS, nearly 1 in 4 (24 percent) reported being abused as children compared with around 1 in 5 (19 percent) of those who didn’t develop MS.Even after accounting for factors that may influence whether or not a person develops MS, including smoking, obesity, educational attainment, and household income, the women who had been abused as children were more likely to be diagnosed with MS.The association was strongest for sexual abuse (65 percent heightened risk), followed by emotional abuse (40 percent heightened risk), and physical abuse (31 percent heightened risk).
The risk of developing MS was even higher (66 percent) if a woman had been exposed to two categories of abuse and rose to 93 percent if she had been exposed to all three categories of childhood trauma, suggesting a ‘dose-response’ association, according to the authors. Researchers found similar associations after they excluded women who might have been in the early (prodromal) phase of MS when obvious symptoms had yet to appear. The association also persisted when women who had already been diagnosed with MS at the start of the study were included.
PTSD and Chronic Stress Caused by Trauma May Play a Role in Findings
Childhood trauma results in PTSD and chronic stress, which may be partly how it influences the likelihood a person will develop MS, says Jacobs. “[Chronic stress] in turn results in the release of stress hormones which impact the immune system,” she says. Other factors associated with childhood abuse, such as increased risk of obesity, smoking, and perhaps even lower vitamin D levels (victims of abuse may be less likely to get outside and care for themselves in ways that may lower vitamin D levels) may play a role, says Jacobs. Obesity, smoking, and vitamin D deficiency have all been identified as environmental factors that contribute to a person’s overall risk of developing MS, according to the National MS Society. The authors acknowledge a few limitations of the findings. As an observational study, the findings don’t prove that the abuse directly causes MS. Environmental factors such as diet, nutrition, physical activity levels, and parental smoking were not controlled for, but might all be independently important. The duration of the abuse, the age or ages at which it occurred, and what levels of emotional support were available to the women was unknown, noted the authors.
Healthcare Providers Should Be Aware That Some MS Patients May Have Suffered Abuse
These findings are important in part because it’s good to be aware that MS patients may have suffered abuse, says Jacobs. “This may result in high incidence of mood disorders, including depression and anxiety, which may impact one’s ability to properly care for oneself while living with MS. It’s important to make certain our patients have access to appropriate care for any resultant mood disorders and PTSD which may impede one’s ability to best care for oneself,” she says. The Multiple Sclerosis Association of America offers a toll-free help line, which can be accessed by calling 800-532-7667, extension 154, or by email at MSquestions@mymsaa.org. The line is staffed by people with social services and counseling backgrounds Monday through Friday, 8:30 a.m. to 8 p.m. EDT. To reach a Spanish-speaking client services specialist, call 800-532-7667, extension 131.
