Past Childhood Abuse Linked to Increased MS Risk in Norwegian Study
Women who were exposed to sexual or emotional abuse as children may be at an increased risk of developing multiple sclerosis (MS) later in life, according to a large study in Norway.
The risk was even higher among patients who experienced a combination of two or more types of abuse in their childhood, the researchers noted, adding that more research is needed to understand the biological mechanisms through which childhood trauma may contribute to MS.
The study, “Association of adverse childhood experiences with the development of multiple sclerosis,” was published in the Journal of Neurology, Neurosurgery & Psychiatry.
MS is an autoimmune disease that occurs when the immune system mistakenly attacks myelin, a fatty substance that forms a protective sheath around nerves. Exactly what triggers this attack is unknown, but a combination of genetic and environmental factors are thought to play a role.
Trauma is linked to an increased risk of autoimmune diseases, and exposure to abuse, neglect, and a chaotic home life in childhood also makes adults more likely to experience poor mental and physical health.
To know whether exposure to abuse in childhood may increase the risk of MS later in life, researchers in Norway drew on data from the Norwegian Mother, Father and Child cohort study (MoBa). The study included pregnant Norwegian-speaking women across Norway from 1999 to 2008 who were followed up until the end of 2018.
At study entry, women filled in a questionnaire that included questions about exposure to sexual abuse, humiliation and threat (emotional abuse), and physical abuse before the age of 18.
Of the 77,997 women who joined the study, 14,477 (19%) said they were exposed to childhood abuse and 63,520 (81%) said they were not. The women with a history of childhood abuse more often were current or former smokers, were overweight, and had more severe symptoms of depression.
During the follow-up period, 300 women developed MS, based on national health registry data and hospital records. Of those, 71 (24%) had a history of childhood abuse.
After accounting for potentially confounding factors, including smoking, obesity, dropping out of school, and low household income, the researchers found that people who had experienced sexual abuse as children had a 65% higher risk of developing MS. For those exposed to emotional abuse, there was a 40% heightened risk.
Physical abuse also increased the risk of developing MS by 31%, but the results failed to reach statistical significance.
The more forms of childhood abuse a woman had experienced, the greater her risk of MS. For those exposed to a combination of two types of abuse, the risk was 66% higher when compared with women not exposed to any form of abuse, and that risk increased to 93% for those exposed to all three forms of childhood abuse.
Similar findings were obtained when the team excluded women who might have been in the prodromal phase of MS (when symptoms had yet to appear) at the time of abuse, or those who already had a diagnosis of MS when they entered the study.
“Children exposed to adverse experiences had an increased risk of developing MS later in life, independent of known environmental risk factors for MS,” the researchers concluded.
“The risk increased with number of abuse categories in a dose–response manner,” they wrote, adding that “the underlying mechanisms behind this association should be investigated further.”
As a possible mechanism, the researchers noted that childhood abuse can disrupt the interaction between the hypothalamus, the pituitary gland, and the adrenal glands — triggering a lingering status of inflammation that may remain into adulthood. It can also contribute to oxidative stress, a form of cell damage known to contribute to inflammation and nerve cell death in MS.
The team noted a number of limitations in their study, including the lack of information about childhood exposure to environmental factors, and about the timing and duration of abuse. It was also not known if participants who experienced abuse had any form of therapeutic or social support.
“Better understanding of the risk factors and timing of risk exposures, may open doors for prevention and give further insight to disease mechanisms,” the researchers wrote.
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