People diagnosed with attention deficit hyperactivity disorder are more likely to commit crimes when they are not receiving medication, according to a study published Wednesday in the New England Journal of Medicine.
Numerous studies have shown that ADHD is associated with an increase in criminal behavior, but it has remained unclear how medication use influences this equation after adolescence.
The study, which followed 25,656 Swedish people diagnosed with ADHD from 2006 to 2009, is the largest such analysis of the long-term effects of ADHD treatment. The researchers, led by Paul Lichtenstein of the Karolinska Institutet in Stockholm, compared periods in which their subjects were on medication with periods in which they were not. By doing so, they were able to do many comparisons of the same subjects at different points in time, reducing the possibility that confounding factors -- such as socioeconomic status -- would cloud any associations they uncovered (they used statistical methods to control for such factors as well).
A decent number of the subjects committed crimes at some point during the study: 36.6% of men were convicted of a crime, and 15.4% of women.