Study: Sleep Problems in Children Linked to Low Iron, Restless Behavior
Sleep problems are more common among children with restlessness and iron deficiency problems, according to this small study. Results highlight the need to collect bloodwork and family history, especially for children with ADHD.
October 19, 2024
Sleep problems in children are associated with restless behavior and iron deficiency, two problems more common in patients with ADHD, according to a small study published in the journal Nutrients.1
The study followed 199 patients referred to a Sleep/Wake Behavior Clinic between 2021 and 2023. It found that patients with ADHD were nearly twice as likely as their neurotypical counterparts to have restless leg syndrome (RLS). The most common psychiatric comorbidities among patients with sleep disorders included ADHD (46%), autism (45%), and anxiety disorder (41%).
Most patients in the study had an iron deficiency (94%), and 41% knew someone in their family who did. When comparing ADHD patients only, a family history of iron deficiency increased the patient’s risk of having RLS and insomnia.
“Recently, iron has received increasing attention due to its role in sleep disorders, as well as wake behaviors associated with mental health and/or neurodevelopmental disorders such as ADHD, autism spectrum disorder, and prenatal alcohol exposure/fetal alcohol spectrum disorder,” the research authors wrote.
RLS was the most common sleep disorder (74%) in the study, followed by:
- Chronic insomnia: 61%
- Signs of sleep-disordered breathing: 50%
- Restless sleep or PLMS: 30%
- Circadian rhythm sleep disorder (CRSD): 16%
- Probable painful RLS: 11%
Sleep and ADHD
Nearly three-quarters of children with ADHD experience a sleep problem or disorder.2 For many children, sleep problems last into adolescence and can aggravate ADHD symptoms during the day.
“By the time they get into adolescence, we know that teens with ADHD are more likely than their peers without ADHD to get insufficient sleep on school nights,” said Stephen Becker, Ph.D., in his 2021 webinar with ADDitude, “Why Am I Always So Tired? The Latest Science on Improving Sleep in Children and Teens with ADHD.”
“We’ve also shown that poor sleep impacts academics, including academic performance, organization, and lower grades based on report cards that we’ve acquired from schools and college institutions,” Becker said. “In some of our work with young teens, even after we account for a teen’s initial levels of depressive symptoms or oppositional behaviors, those teens who had sleep problems went on to experience an increase in depressive symptoms and oppositional behaviors over time.”
Restlessness, defined as the “urge to move,” was a strong risk factor for sleep problems in children with and without ADHD in the present study. Hypermotor restlessness and hyper-arousal are central to ADHD and RLS but are often missed in pediatric patients, according to the authors. Symptoms of restlessness are based on adult criteria and do not account for physical differences that may be present in children.
“Characterizing hyper-motor restlessness during sleep as a new diagnostic entity supports our understanding that disorders presenting with hypermotor restlessness and/or hyper-arousability need an in-depth phenotyping approach from a pediatric sleep medicine perspective,” the authors wrote.
Limitations & Future Research
Standard diagnostic evaluations for sleep disorders typically do not assess for iron levels, according to the authors. Testing iron levels using blood tests could help improve treatment outcomes, as many patients in the present study were shown to be deficient. The authors noted that iron supplementation is often an effective treatment approach.
Evening activities, screen time, stimulant medication, homework stress, and inconsistent sleep/wake times may also make it difficult for children with ADHD to wind down at night.
Patients ages 3 months to 23 years and/or their family members answered questions upon intake about bedtime habits, excessive daytime sleepiness, nighttime awakenings, routines, sleep-disordered breathing, quality of sleep, and other non-specific concerns. The Sleep Disturbance Scale for Children (SDSC) and ADHD Rating Scale-IV were also administered.
The study has several limitations, including the absence of a control group and a small sample size. Additionally, medication use was not controlled, and there was no distinction made between anemic and non-anemic individuals with iron deficiency, nor between maternal and paternal family histories. Future research should explore the causes of iron deficiency. Inadequate nutrition, inflammation, and malabsorption were listed as potential contributors to iron deficiency.
Findings associated with other psychiatric disorders, including autism, were also shared in the study and can be found here.
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1 Ipsiroglu, O.S., Pandher, P.K., Hill, O., McWilliams, S., Braschel, M., Edwards, K., Friedlander, R., Keys, E., Kuo, C., Lewis, M.S., et al. (2024). Iron deficiency and restless sleep/wake behaviors in neurodevelopmental disorders and mental health conditions. Nutrients, 16(18):3064. https://doi.org/10.3390/nu16183064
2 Sung, V., Hiscock, H., Sciberras, E., Efron, D. (2008). Sleep problems in children with attention-deficit/hyperactivity disorder: prevalence and the effect on the child and family. Arch Pediatr Adolesc Med, 162(4):336–342. https://doi.org/10.1001/archpedi.162.4.336
