ADHD Drugs Can Reduce Criminality

Patients receiving medication for attention-deficit/hyperactivity disorder appear to be significantly less likely to commit crimes, according to the results of a study.

Patients with attention-deficit/hyperactivity disorder (ADHD) appear to have significantly lower levels of criminality when they are being treated with ADHD drugs compared with when they are not, according to the results of a study published in the November 22, 2012, edition of the New England Journal of Medicine.

The researchers, based at the Karolinska Institute in Stockholm, Sweden, looked at data on 25,656 ADHD patients (16,087 men and 9569 women) born in 1990 or before who had at least 1 diagnosis of ADHD in Sweden’s National Patient Register. They also looked at a general population sample, with 10 controls matched to each case, to contrast rates of criminality and medication use with those who were diagnosed with ADHD.

Among the men diagnosed with ADHD, 53.6% took an ADHD medication (such as methylphenidate, amphetamine, dextroamphetamine, or atomoxetine), and 36.6% were convicted of at least 1 crime during follow-up. The corresponding numbers for the matched general population controls were 0.2% and 8.9%. Among the women diagnosed with ADHD, 62.7% took an ADHD medication, and 15.4% were convicted of at least 1 crime during follow-up, compared with 0.1% and 2.2% of the controls, respectively.

ADHD patients committed crimes that led to conviction significantly less frequently when they were taking ADHD medication. After adjustment for all confounding variables, men with ADHD were 32% less likely and women were 41% less likely to be convicted of a crime when taking ADHD medication than when not taking ADHD medication.

In sensitivity tests on male patients, similar reductions in criminality were found when patients were taking a stimulant ADHD medication (34% reduction) as when they were taking a nonstimulant ADHD medication (24% reduction) and when the analysis was restricted to less severe or specific crimes. When suspicion of a crime was used as the outcome instead of conviction, there was still a reduction in patients’ criminality rate during treatment periods.

To ensure that criminality wasn’t the cause of patients’ stopping treatment, the researchers looked at the change in rates of criminality when patients went on or off medication and found that the associations were significant regardless of the sequence. There was, however, no finding that taking medication had a long-term effect on reducing criminality.