Study: Chronic Fatigue Twice as Likely Among Children with ADHD
The link between ADHD and chronic fatigue is illuminated by a new study that suggests higher levels of inflammation in neurodivergent kids may be to blame.
August 20, 2024
Children with ADHD or autism are twice as likely to experience chronic disabling fatigue by the age of 18, even when controlling for comorbid depression, according to a new study published in the journal BMJ Open. Researchers point to the high levels of inflammation (often resulting from elevated stress levels) found among research subjects as a possible explanation for this association.1
While previous research has demonstrated a high prevalence of chronic fatigue in patients with ADHD,2 this is the first study to investigate potential mechanisms underlying the association.
Data from The Avon Longitudinal Study of Parents and Children (ALSPAC) was analyzed to assess whether children who scored above the threshold for ADHD or autism at ages 7 and 9 had an increased risk of chronic disabling fatigue at age 18. Mediation analyses were performed to investigate whether an inflammatory marker (IL-6) at age 9 was linked to fatigue and neurodivergence.
In fact, it did. IL-6 levels at age 9 were associated with a higher likelihood of chronic disabling fatigue at age 18. Though the causes of inflammation are myriad, it is often exacerbated by elevated stress levels, common among neurodivergent children.
“Research shows that neurodivergent children experience higher levels of loneliness, and are more likely to experience bullying,” the authors of the study explain. “Neurodivergent children are also more vulnerable to experience pain.”
In addition to chronic fatigue, adults with ADHD suffer in higher numbers with many different physical conditions. In fact, a recent study found that adults with ADHD are at elevated risk for 34 of 35 conditions studied, including nervous system, respiratory, musculoskeletal, metabolic, circulatory, gastrointestinal, genitourinary, and skin conditions. 3 These include:
- ulcer or chronic gastritis
- pulmonary disease
- Type 2 diabetes
- epilepsy
- heart failure
- kidney infections
- spinal conditions
- eczema
The mechanisms of action underlying the association between ADHD and its comorbid physical conditions are not yet known, but this study brings us one step closer to understanding a complex and critically important picture, the authors of the study explain.
“Children who are suspected to be or diagnosed as neurodivergent should routinely be screened for physical and mental health concerns,” they urge. “Earlier integration of brain-body concerns in a holistic framework can facilitate tailored support and improve quality of life of neurodivergent individuals.”
Putting a Spotlight on Chronic Fatigue
“When you think of hyperactivity, you think of talking non-stop, fidgeting, interrupting, distractible,” says Walt Karniski, M.D., a developmental pediatrician. “Lethargy is the last thing you would think about.” Yet, Karniski says he has seen an increase in pediatric patients who present with lethargy as one of the most problematic symptoms. A slightly different approach is needed to treat ADHD patients dealing with chronic fatigue, he adds.
The authors of the study assessed the presence of “chronic disabling fatigue” (defined broadly as lacking energy and getting tired during the last month) rather than the presence of myalgic encephalomyelitis/chronic fatigue syndrome because up to 91% of ME/ CFS cases go undiagnosed. “Despite its evident detrimental impact on quality of life, prolonged or chronic fatigue as a medical symptom is frequently described as an ‘unexplained’ symptom, and patients regularly report being dismissed about their experience,” the study’s authors write.
The symptoms of ME/ CFS include chronic widespread pain, unrefreshing sleep and rest, and dysfunction in the areas of memory, attention, and cognition — many of the same symptoms as ADHD.
“Neurodivergence and chronic fatigue are conditions with complex individual neurodevelopmental pathways,” the researchers explain. “It is therefore likely that inflammation is not the only mediating or moderating factor […] Additional mechanistic insights are needed to disentangle the intricacies of this relationship.”
As is the case with all ADHD comorbidities, optimized treatment is a byproduct of comprehensive diagnostic care and a holistic picture of each individual’s conditions. When diagnoses are missed, patients suffer.
“For years I have struggled with chronic fatigue syndrome, going in cycles of boom and bust. I would work successfully for years, energetic and committed to what I was doing. Eventually, I could no longer sustain the pace and would crash, taking months to recover, unable to work,” explains Cathy, an ADDitude reader in the United Kingdom. “Only recently have I realized that I also have ADHD and begun my journey to a formal diagnosis.”
Polly, an ADDitude reader with chronic fatigue syndrome, depression, anxiety, and chronic pain, shares this: “I have taken various medications over the years for these issues, which have had benefits and drawbacks but never resolved anything. It is so clear to me now where the root of it all lies. I’ve only recently realized, at the age of 60, that I am neurodivergent and probably have ADHD.”
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1 Quadt, L., Csecs, J., Bond, R., et al. (2024). Childhood Neurodivergent Traits, Inflammation and Chronic Disabling Fatigue in Adolescence: A Longitudinal Case Control Study. BMJ Open. 14:e084203. doi.org//10.1136/bmjopen-2024-084203
2 Sáez-Francàs, N., Alegre, J., Calvo, N., et al. (2012). Attention-Deficit Hyperactivity Disorder in Chronic Fatigue Syndrome Patients. Psychiatry Res. 200: 748, 53 doi:10.1016/j.psychres.2012.04.041
3 Du Rietz, E., Brikell, I., Butwicka, A., Leone, M., Chang, Z., Cortese, S., D’Onofrio, B.M., Hartman, C.A., Lichtenstein, P., Faraone, S.V., Kuja-Halkola, R., Larsson, H. (2021). Mapping Phenotypic and Aetiological Associations Between ADHD and Physical Conditions in Adulthood in Sweden: A Genetically Informed Register Study. Lancet Psychiatry. 8(9):774-783. doi.org/10.1016/S2215-0366(21)00171-1
