There appears to be a clear correlation between how early babies are born and their risk of being prescribed ADHD (attention-deficit/hyperactivity disorder) medications later in life, researchers from the Karolinska Institute, Sweden, revealed in the journal Pediatrics. The authors even found an elevated risk of developing ADHD among babies born at 36 weeks, just three weeks early.
As background information, the researchers explain that prior studies had shown an elevated risk for ADHD in follow-up studies of premature babies who survived neonatal intensive care units.
The team set out to determine what effect moderate and extreme preterm birth might have on ADHD risk in school age children, after factoring in such variables as family history (genetics), smoking status during pregnancy, perinatal factors, and socioeconomic confounders.
They gathered and analyzed data from a Swedish database of over a million children aged between 6 and 19 years, of which 7,506 had been prescribed ADHD drugs.
Those with the highest risk of subsequently developing ADHD were born between 23 and 28 weeks of pregnancy - two and a half times higher than those born at 39 weeks (full term).
15 in every 1,000 babies born at between 23 and 28 weeks of pregnancy went on to be prescribed ADHD drugs, versus 6 in every 1,000 born full term.
Even babies born at 37 weeks had a 20% higher risk of being prescribed ADHD later in life (7 in every 1,000 of them), according to lead author Dr. Anders Hjern.
The authors stress that their study gathered data on children who were prescribed ADHD medications, not those who were diagnosed with ADHD.
The authors concluded in an Abstract in Pediatrics:
"Preterm and early term birth increases the risk of ADHD by degree of immaturity. This main effect is not explained by genetic, perinatal, or socioeconomic confounding, but socioeconomic context modifies the risk of ADHD in moderately preterm births.
"Preterm Birth and Attention-Deficit/Hyperactivity Disorder in Schoolchildren"
Karolina Lindström, MD, Frank Lindblad, MD, PhD, Anders Hjern, MD, PhD
Written by Christian Nordqvist