What triggers attention-deficit/hyperactivity disorder (ADHD)?
While the exact cause of this common neurodevelopmental disorder, characterized by persistent, impairing levels of inattention, hyperactivity, and impulsivity, is unknown, it is considered a brain-based, heavily genetic condition and one of the most common mental developmental disorders affecting children.
Treatment for the condition, which has genetic and environmental factors but is not tied to a single gene, typically includes medication, behavioral therapy, or a combination.
Among the most famous sufferers of ADHD are Olympic champion swimmer Michael Phelps, the most decorated Olympian of all time, with a total of 28 medals; Simone Biles, whose 11 Olympic medals and 30 World Championship medals make her the most decorated gymnast in history; billionaire entrepreneur Richard Branson; Harry Potter movie actress Emma Watson; and American astronaut Scott Kelly, whose careers may even have benefited from their condition.
The symptoms include inattention (not being able to keep focus), hyperactivity (excess movement that is not fitting to the setting), and impulsivity (hasty acts that occur in the moment without thinking).
ADHD is known to impact professional achievements
ADHD is considered a chronic and debilitating disorder that is known to impact the individual in many aspects of their life, including academic and professional achievements, interpersonal relationships, and daily functioning.
Among children’s symptoms are difficulty staying focused, forgetfulness, losing items, poor organization, failure to listen, and avoiding tasks that require sustained mental effort; fidgeting; inability to sit still; excessive talking; interrupting others; and acting without thinking.
In adults, hyperactivity may appear as extreme restlessness or wearing others out.
A 17-year longitudinal study from Ben-Gurion University of the Negev (BGU) in Beersheba has followed children from birth to adolescence to examine whether early-life factors predict ADHD. It is known to involve lower levels of dopamine and lower metabolism in brain areas controlling attention and movement.
Among the risk factors are premature birth, low birth weight, brain injuries, and a familial history of the condition.
In preschool-age and younger children, the recommended first-line approach includes behavioral strategies in the form of parent management training and school intervention.
There is, as yet, no cure, but reducing the symptoms includes a combination of therapy and taking medication. In some children, the symptoms decline as they reach adulthood.
Published in Infant and Child Development under the title “Neonatal surgency moderates the association between the home environment and executive functions (EF) in children with a family history of ADHD,” the study tracked 125 boys and their parents, examining the babies’ temperaments, parental ADHD symptoms, and the richness of the early home environment. Their key finding was that early risk factors don’t affect all children equally.
Led by psychology Prof. Andrea Berger, who is a member of BGU’s Department of Psychology and the School of Brain Sciences and Cognition and emerita Prof. Judith Auerbach, together with Dr. Tzlil Einziger (of the Ruppin Academic Center), the researchers found that infants showing high motor activity, especially those with parents who have more ADHD symptoms – were more sensitive to their surroundings.
Berger earned her degrees as a psychologist at BGU and completed post-doctoral studies at the University of Oregon recently served two terms as chairman of the psychology department.
The world average of ADHD in children is estimated at 4.5% to 5%, and in addition to the complex genetic causes, there seem to be substantial environmental influences.
Estimates among Israeli children are higher; a large population study of 284,000 Israeli children (ages six to 13) found a prevalence of about 12.6%.
“The seemingly higher rate of ADHD in Israeli children is not due only to overdiagnosis; it is likely related to the extremely stressful events to which they have been exposed, from constant terror attacks, wars, the COVID pandemic, being taught in too-large classes, and more,” Berger continued.
“And there are no free or easily available high-quality frameworks for infants and toddlers from birth to age three,” she said.
But this could be due to more diagnoses by very accessible pediatrics. Israel is among the countries with the highest use of ADHD medications such as methylphenidate (known by brand names like Ritalin and Concerta).
These drugs are even taken by university students who get their hands on them even though they don’t have ADHD, which often is accompanied by learning disabilities, Berger told The Jerusalem Post in an interview.
ADHD-like symptoms were first described by Sir Alexander Crichton in 1798 as “mental restlessness,” while Sir George Still provided the first clinical description of hyperactive/impulsive children in 1902.
Formal recognition evolved through terms like “hyperkinetic disease” in the 1930s, before the term ADHD was adopted in the 1987 Diagnostic and Statistical Manual of Mental Disorders III-R.
“Twenty-seven years ago, when the BGU study began, all ADHD research focused on boys. Nowadays, more attention is devoted also to girls with ADHD, and we include them in our current studies.”
For those boys who were followed, a rich and supportive home environment strongly predicted better cognitive functioning by age seven, which in turn was linked to fewer ADHD symptoms in later childhood and adolescence.
The same sensitivity meant they benefited most from supportive environments and were more negatively affected by less-enriching ones. “There aren’t just ‘sensitive’ and ‘non-sensitive’ children,” Berger explained. “Sensitivity exists on a continuum, shaped by the interaction between child temperament and parental characteristics.”
Those children who experienced a less-enriched environment showed lower EF at seven years of age, while those who experienced a more enriched home environment demonstrated the highest levels of EF in that sample, outperforming their peers whose parents had low symptomatology.
The relation between the home environment and child EF was not significant among children of parents with low ADHD symptoms.
“Additionally, higher levels of child EF were associated with lower levels of child ADHD symptoms, measured both concurrently and in adolescence. “Understanding this can help tailor early environments to better support children who need it most,” Einziger added.
Indeed, parental ADHD symptoms have been linked to challenges in parenting, such as inconsistency and intrusiveness, but also to certain strengths, including high energy and spontaneity, although these have been less frequently examined.
Thus, the home environment created by parents who have themselves significant symptoms of ADHD might impact the development of their highly sensitive children, even more strongly than in the case of children of parents with low symptomatology.
Understanding the role of sensitivity to the environment in ADHD can contribute to early interventions focused on helping parents with the condition to create a supportive and better-adapted environment for their children, the researchers found.
“Identifying multiple factors of sensitivity might enhance the identification of sensitive children. The combination of such factors could help target children who might be more sensitive to the environment, being more negatively affected by a less enriching environment, yet benefit most from an enriching environment,” Berger said.
“Early identification of these sensitivity factors could promote the implementation of intervention programs very early in their development. These programs should focus on helping parents with ADHD create supportive and enriching environments, despite their own symptoms and unique challenges.
Improving the home environment of children with elevated levels of developing ADHD could improve their developmental outcomes, especially in their cognitive abilities,” she concluded.