The research, which analysed data from nearly 150,000 individuals in Sweden between 2007 and 2020, compared outcomes for newly diagnosed people who received medication versus those who did not.
Among those starting medication, there was a 17 per cent reduction in suicidal behaviour, 15 per cent in substance misuse, 12 per cent in transport accidents, and 13 per cent in criminality.
For individuals experiencing recurrent adverse events, medication led to even greater reductions across all five outcomes, including a 25 per cent decrease in substance misuse and criminality.
Despite an estimated 2.6 million people living with ADHD in the UK, just over half are prescribed medication, prompting experts to highlight the need for greater awareness of the long-term risks associated with unmedicated ADHD.