Children who are the youngest in their class diagnosed with ADHD are just as likely to have the diagnosis as older students in their year group, scientists have found.
Experts from the University of Southampton and the University of Paris Nanterre, working with researchers worldwide, made the discovery after examining data from thousands of patients with attention deficit hyperactivity disorder.
In the past, scientists have questioned the validity of diagnosing ADHD in young students – arguing that they receive it because they are less mature than those born at the beginning of the school year.
But the study, published in Lancet Psychiatry, found that children who were the youngest in the class and diagnosed with the condition were just as likely to retain it later as their older peers.
Professor Samuel Cortes, a child and adolescent psychiatrist at the University of Southampton, said: “We know the youngest children in their year group are more likely to be diagnosed with ADHD – but many believe this is because they are lagging behind their elders. classmate
“However, whether these young children diagnosed with ADHD retain the diagnosis later on – no one has yet investigated. Our study shows for the first time that these young children are no more likely to miss the diagnosis over time than older children. “
According to the World Health Organization, around 360 million people under the age of 18 are diagnosed with ADHD worldwide.
Symptoms include impulsiveness, disorganization, poor time management skills, difficulty focusing, and restlessness.
The research from Southampton and Paris Nanterre, conducted with 161 scientists worldwide, is based on the largest data set ever created to explore the influence of month of birth on the persistence of ADHD.
In total, it examined data from more than 6,500 patients worldwide who were followed for a period between the ages of four and 33.
Dr Corentin Gosling, an associate professor at the University of Paris Nanterre in France and visiting researcher at Southampton, is the first author of the study.
He said: “Our work shows that the diagnosis of ADHD in relatively young children is not particularly unstable.
“However, we could not assess whether this is an appropriate diagnosis or whether it is because, once a child receives the ADHD label, parents and teachers perceive the child as having ADHD and are influenced by the diagnosis. Future studies should address this question.”
Synergy for birth month effects in the ADHD (SIMBA) study group. (2023) Association between relative age at school and persistence of attention-deficit hyperactivity disorder in a prospective study: an individual participant data meta-analysis.. Lancet Psychiatry. doi.org/10.1016/S2215-0366(23)00272-9.