November 16, 2023
The US Center for Disease Control's (CDC)review of ADHD starts with the statement: "Attention-deficit/hyperactivity disorder (ADHD) is a serious public health problem affecting many children and adults" (http://www.cdc.gov/ncbddd/adhd/research.html). My colleagues and I recently reviewed the ADHD literature. That let us describe ADHD as "... a seriously impairing, often persistent neurobiological disorder of high prevalence..." (Faraone et al., 2015). The figure 1, which comes from that paper, provides an overview of the lifetime trajectory of ADHD-associated morbidity.
Especially compelling data about ADHD and injuries comes from a recent paper, in Lancet Psychiatry, which used the Danish national registers to follow a cohort of 710,120 children (Dalsgaard et al., 2015a). Compared with children not having ADHD, those with ADHD were 30% more likely to sustain injuries than other children. Pharmacotherapy for ADHD reduced the risk for injuries by 32% from 5 to 10 years of age. Pharmacotherapy for ADHD reduced emergency room visits by 28.2% at age 10and 45.7% at age 12.
These results are shown in Figure 2, taken from the publication.
Especially compelling data about ADHD and injuries comes from a recent paper, in Lancet Psychiatry, which used the Danish national registers to follow a cohort of 710,120 children (Dalsgaard et al., 2015a). Compared with children not having ADHD, those with ADHD were 30% more likely to sustain injuries than other children. Pharmacotherapy for ADHD reduced the risk for injuries by 32% from 5 to 10 years of age. Pharmacotherapy for ADHD reduced emergency room visits by 28.2%at age 10and 45.7% at age 12.
These results are shown in Figure2, taken from the publication. The Figure compares the prevalence of injuries among three groups. ADHD children treated with medication, ADHD children not treated with medication, and children without ADHD. The Figure shows how ADHD risk for injuries occurs for all age groups. It also shows how the risk for injuries drops with treatment so that by age 12, the prevalence of injuries among treated ADHD children is the same as the prevalence of injuries for children without ADHD.
Documented examples of ADHD-associated injuries which impact day-to-day functioning include severe burns (Fritz and Butz, 2007), dental injuries (Sabuncuoglu, 2007), penetrating eye injuries (Bayar et al., 2015), the hospital treated injuries (Hurtig et al., 2013), and head injuries (DiScala et al., 1998). In one study (DiScala et al., 1998), when compared to other children admitted to the hospital for injuries, ADHD children were more likely to sustain injuries in multiple body regions (57.1% vs 43%), sustain head injuries (53% vs 41%), and to be severely injured as measured by the Injury Severity Score (12.5% vs5.4%) and the Glasgow Coma Scale (7.5% vs 3.4%).
Injuries are a substantial cause of ADHD-associated premature death. This assertion comes from the work of Dalsgaard et al. (2015b)based on the same Danish registry discussed above. In this second study, ADHD was associated with an increased risk for premature death and 53% of those deaths were due to injuries. They reported the risk for premature death in three age groups: 1-5, 6-17, and >17. For all three age groups, they found a greater risk for death in the ADHD group. For ages 6 to 17 and greater than 17. The ADHD-associated risk for mortality remained significant after excluding individuals with antisocial or substance use disorders.
There are currently no data about the effect of ADHD treatment on ADHD-associated premature death. We do, however, know from the data reviewed above that ADHD treatment reduces injuries and that half the deaths in the ADHD group were due to injuries. From this, we infer that ADHD treatments could reduce the risk of ADHD-associated premature death.
Two other ADHD-associated mobilities, obesity and cigarette smoking, have clear medical consequences. In a meta-analysis of 42 cross-sectional studies comprising 48,161 people with ADHD and 679,975 controls, my colleagues and I reported that the pooled prevalence of obesity was increased by about 40% in ADHD children compared with non-ADHD children and by about 70% in ADHD adults compared with non-ADHD adults(Cortese et al.,2015). The association between ADHD and obesity was significant for ADHD medication-naïve subjects but not for those medicated for ADHD, which suggests that medication reduces the risk for obesity.
Likewise, a meta-analysis of 27 longitudinal studies assessed the risk for several addictive disorders with sample sizes ranging from 4142 to 4175 for ADHD and 6835 to 6880 for non-ADHD controls (Lee et al., 2011). Children with ADHD were at higher risk for disorders of abuse or dependence on nicotine, alcohol, marijuana, cocaine, and other unspecified substances. Another meta-analysis (42 studies totaling, 2360 participants) showed that medications for ADHD reduced the ADHD-associated risk for smoking (Schoenfelder et al., 2014). The authors concluded that, for ADHD patients, "Consistent stimulant treatment for ADHD may reduce the risk of smoking". This finding is especially notable given that, for ADHD youth, cigarette smoking is a gateway drug to more serious addictions (Biederman et al., 2006).
Yes, ADHD is a serious disorder. Although most ADHD people will be spared the worst of these outcomes, they must be considered by parents and patients when weighing the pros and cons of treatment options.
Bayar, H., Coskun, E., Oner, V., Gokcen,C., Aksoy, U., Okumus, S. & Erbagci, I. (2015). Association between penetrating eye injuries and attention deficit hyperactivity disorder in children.Br J Ophthalmol99, 1109-11.
Biederman, J., Monuteaux, M., Mick, E., Wilens, T., Fontanella, J.,Poetzl, K. M., Kirk, T., Masse, J. & Faraone, S. V. (2006). Is cigarette smoking a gateway drug to subsequent alcohol and illicit drug use disorders? A controlled study of youths with and without ADHD. Biol Psychiatry59, 258-64.
Cortese, S., Moreira-Maia, C. R., St Fleur, D., Morcillo-Penalver, C.,Rohde, L. A. & Faraone, S. V. (2015). Association Between ADHD and Obesity: A Systematic Review and Meta-Analysis. Am J Psychiatry, appiajp201515020266.
Dalsgaard, S., Leckman, J. F., Mortensen, P. B., Nielsen, H. S. &Simonsen, M. (2015a). Effect of drugs on the risk of injuries in children with attention deficit hyperactivity disorder: a prospective cohort study. Lancet Psychiatry2, 702-9.
Dalsgaard, S., Ostergaard, S. D., Leckman, J. F., Mortensen, P. B.& Pedersen, M. G. (2015b). Mortality in children, adolescents, and adults with attention deficit hyperactivity disorder: a nationwide cohortstudy. Lancet385, 2190-6.
DiScala, C., Lescohier, I., Barthel, M. & Li, G. (1998).Injuries to children with attention deficit hyperactivity disorder. Pediatrics102, 1415-21.
Faraone, S. V., Asherson, P., Banaschewski, T., Biederman, J.,Buitelaar, J. K., Ramos-Quiroga, J. A., Rohde, L. A., Sonuga-Barke, E. J. S.,Tannock, R. & Franke, B. (2015). Attention deficit hyperactivitydisorder. In Nature Reviews: DiseasePrimers.
Fritz, K. M. & Butz, C. (2007). Attention Deficit/Hyperactivity Disorder and pediatric burn injury: important considerations regarding premorbid risk. Curr Opin Pediatr19, 565-9.
Hurtig, T., Ebeling, H., Jokelainen, J., Koivumaa-Honkanen, H. &Taanila, A. (2013). The Association Between Hospital-Treated Injuries and ADHD Symptoms in Childhood and Adolescence: A Follow-Up Study in the Northern Finland Birth Cohort 1986. J Atten Disord.
Lee, S. S., Humphreys, K. L., Flory, K., Liu, R. & Glass, K. (2011).Prospective association of childhood attention-deficit/hyperactivity disorder(ADHD) and substance use and abuse/dependence: a meta-analytic review. Clin Psychol Rev31, 328-41.
Sabuncuoglu, O. (2007). Traumatic dental injuries and attention-deficit/hyperactivity disorder: is there a link? Dent Traumatol23,137-42.
Schoenfelder, E. N., Faraone, S. V. & Kollins, S. H. (2014).Stimulant treatment of ADHD and cigarette smoking: a meta-analysis. Pediatrics133, 1070-1080.
There has been consistent evidence of an association between ADHD and subjectively reported sleep problems even in patients not medicated for the disorder. There have also been studies using wrist-worn actigraphy (a wrist watch-like device that measures gross motor activity) and sleep lab-based polysomnography that measure objective sleep parameters.
What has been missing are large population-based cohort studies to explore the prevalence rates of different sleep disorders and medical prescriptions in ADHD.
Methods Used:
Sweden has a single-payer health insurance system and a series of national population registers that track virtually its entire population. Using the Swedish Total Population Register, a local research team created a cohort of all 6,470,658 persons born between 1945 and 2008. They linked this to the Swedish National Patient Register, which includes inpatient hospitalizations from 1975 to 2013, and outpatient specialist diagnoses from 2001 to 2013, to identify diagnoses of sleep disorders. They also linked to the Prescribed Drug Register, covering 2005 to 2013, to identify prescriptions for sleep medications.
Summary of Findings:
Overall, persons with ADHD were eight times more likely to be diagnosed with any sleep disorder relative to normally developing peers. Broken down by age, adolescents with ADHD were 16 times more likely to receive such diagnoses, young adults (18-30) twelve times more likely, children and mid-age adults (31-45) eight times more likely, and older adults six times more likely.
Broken down by specific sleep disorder diagnoses, relative to normally developing peers, persons with ADHD were:
As for sleep medication, relative to normally developing peers, persons with ADHD were:
Conclusion:
The team concluded, “Our findings also suggest that greater clinical attention should be directed towards addressing sleep problems in individuals with ADHD. This entails implementing proactive measures through sleep education programmes and providing both pharmacological and non-pharmacological approaches such as cognitive behavioural therapy and parental sleep training.”
Attention is a critical determinant of academic achievement, influencing domains such as language, literacy, and mathematics. To explore whether physical activity can improve attention in children with ADHD, an international team conducted a meta-analysis of peer-reviewed studies. The goal was to evaluate the impact of various physical activity regimens on attention-related outcomes in this population.
The researchers performed a comprehensive search of the medical literature to identify studies examining the effects of physical activity on attention in schoolchildren with ADHD. They included 10 studies with a total of 474 participants in their meta-analysis. The studies evaluated two main types of physical activity:
Additionally, they examined variations based on the frequency, duration, and type of control groups used in the studies. To assess consistency, they also analyzed heterogeneity (variability of outcomes) and checked for potential publication bias.
Key findings from the meta-analysis include:
The authors concluded that mentally engaging exercise is more effective than aerobic exercise in improving attention problems in schoolchildren with ADHD. Furthermore, higher frequency and longer duration of physical activity do not necessarily yield better outcomes.
This research underscores the importance of tailoring physical activity interventions to emphasize cognitive engagement over intensity or duration. By refining strategies, educators and parents can better support children with ADHD in achieving academic success. But take note: given the results from controlled studies, it seems clear that if there is a positive effect of exercise, it is very small so should not replace standard treatments for ADHD.
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Previous studies have examined how stimulant medications affect the brain in controlled settings, but less is known about their impact in real-world conditions, where children may not always take their medication consistently or may combine it with other treatments. A new study leverages data from the Adolescent Brain Cognitive Development (ABCD) study to explore how real-world stimulant use impacts brain connectivity and ADHD symptoms over two years.
Changes in Brain Connectivity Researchers used brain imaging data from the ABCD study to examine the functional connectivity—communication between brain areas—of six regions within the striatum, a brain area involved in motivation and movement control. They focused on how stimulant use influenced connectivity between the striatum and other networks involved in executive functioning and visual-motor control.
The study found that stimulant exposure was linked to reduced connectivity between key striatal areas (such as the caudate and putamen) and large brain networks, including the frontoparietal and visual networks. These changes were more pronounced in children taking stimulants compared to those who were not medicated, as well as compared to typically developing children. Importantly, this reduction in connectivity seemed to regulate certain brain networks that are typically altered in children with ADHD.
Symptom Improvement In addition to brain changes, 14% of children taking stimulants experienced a significant reduction in ADHD symptoms over the two-year period. These children showed the strongest connectivity reductions between the right putamen and the visual network, suggesting that stimulant-induced connectivity changes may contribute to improvements in visual attentional control, which is a common challenge for children with ADHD.
Why This Matters This study is one of the first to examine how stimulant use in real-world conditions affects brain networks in children with ADHD over time. The findings suggest that stimulants may help normalize certain connectivity patterns associated with ADHD, particularly in networks related to attention and control. These insights could help clinicians better understand the potential long-term effects of stimulant treatment and guide personalized approaches to ADHD management.
Conclusion Stimulant medications appear to alter striatal-cortical connectivity in children with ADHD, with some changes linked to symptom improvement. This research highlights the potential for stimulant medications to impact brain networks in ways that support attention and control, highlighting the importance of understanding how real-world medication use influences ADHD treatment outcomes.
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