A national Swedish study involving the 1.16 million children in a national birth cohort identified nearly 8000 on the country's Prescribed Drug Register as using a prescription for ADHD medication (and thus assumed to suffer from severe ADHD). These children were significantly more likely to come from a family on welfare benefits (135% more likely), to have a mother with only the most basic education (130% more likely than those with mothers with university degrees), and to come from a single parent family (54% more likely). Boys were three times more likely to be on ADHD medication than girls, with medication use highest in boys aged between 10 and 15. The finding that family adversity is such a strong risk factor points to the need for more research into the role of environment
(2010). Social adversity predicts ADHD-medication in school children – a national cohort study.
Acta Pædiatrica. 99(6), 920 - 924.