Long-term criminal outcome of children with attention deficit hyperactivity disorder

Long-term outcome studies of child psychiatric populations are often limited by attrition. Our study uses the Danish National Crime Register to report on the largest and most complete prospective study of adult criminality as an outcome for children with socioeconomic status attention deficit hyperactivity disorder (ADHD) and is the first to report on the adult criminal outcome of girls with ADHD.

To estimate the relative risk (RR) of adult criminal convictions of children with ADHD compared with the rate in the general population.

A clinical sample of 206 children who had attended a regional child and adolescent psychiatric clinic in Denmark between 1968 and 1989 and received a diagnosis of ADHD was identified. Official criminal conviction data were collected for all of them up to the year 2000 when their mean age was 31 years. Their rate of sustaining at least one criminal conviction was compared with that in an age-matched general population sample.

Ninety-seven (47%) of the children with ADHD had criminal convictions in adulthood. Children with ADHD were about five times more likely to sustain convictions than their peers in the general population (rate ratio (RR) 5.6, 95% confidence interval 5.2-6.1) and twelve times more likely to have violent convictions (RR 12.0, 95% confidence interval 9.9-14.5). Fifty-four (26%) of the children with ADHD without any conduct problems in childhood were convicted in adulthood. Girls with ADHD were also at increased risk of criminal convictions.

Children with ADHD have a higher risk of criminal convictions in adulthood than previously documented, and both girls and boys are at increased risk. Co-morbid conduct problems in childhood are highly predictive of criminal convictions in adulthood. Even in the absence of conduct problems, however, childhood ADHD is associated with increased risk of criminality.