Criminal behavior in people with attention-deficit hyperactivity disorder is lower when they are taking medication, according to a study that may lead to wider acceptance of drug treatment for the condition.
Analyzing Sweden’s registries of patients, drug prescriptions and crime, researchers found that among 25,656 patients over the age of 15 diagnosed with ADHD, crime rates over a four-year period were 32 percent lower in men and 41 percent lower in women when they were on medication compared with when they weren’t. The study, funded by the Swedish Research Council, the U.S. National Institutes of Health and the U.K.’s Wellcome Trust, was published today in the New England Journal of Medicine.
The findings may be extrapolated to the rest of western Europe as rates of crime and medication are similar, while prescription rates are higher in the U.S., said Seena Fazel, one of the study’s authors and a senior research fellow at the Wellcome Trust. The study may support the view that treatment helps patients engage more positively in society, particularly in school and in employment, he said, adding that drugs’ side effects must be considered.
“This adds to the broader picture of how you weigh up the costs and benefits of medication,” Fazel, who is also senior lecturer at Oxford University’s department of psychiatry, told reporters in London yesterday.
15 to 24
About half of the patients were between the ages of 15 and 24 at the start of the study period. About a fifth of adolescent girls and 12 percent of boys in detention and correctional facilities suffer from ADHD, according to a review of 25 surveys published in the Journal of the American Academy of Child and Adolescent Psychiatry in 2008.
The study compared patients’ behavior while on drug treatment with their activity when they were off medication for a period of at least six months, which could occur if they missed appointments to refill prescriptions or if they just chose to forgo drugs, Fazel said.
This may have resulted in a more accurate outcome than comparing patients on medication against a separate population that has never taken drugs because different underlying factors such as genetics, environment and socio-demographics could confound the results, he said.
“We have shown that ADHD medication very probably reduces the risk of crime,” said Henrik Larsson, associate professor at Sweden’s Karolinska Institute and another author of the study. “However, we need to point out that most medical treatments can have adverse side effects, so risks must be weighed up against benefits.”
Pills used to treat ADHD can raise blood pressure and heart rate. Medicines include amphetamines like Shire Plc’s Adderall XR, as well as other drugs such as Novartis AG’s Ritalin, Johnson & Johnson’s Concerta, Shire’s Vyvanse and Intuniv and Eli Lilly & Co.’s Strattera. In Sweden, Concerta is widely prescribed, said Philip Asherson, professor of molecular psychiatry at King’s College London.
ADHD, which causes inattentiveness, over-activity and impulsiveness, is diagnosed in as many as 7 percent of children and 4 percent of adults, according to the American Academy of Child and Adolescent Psychiatry website.
The condition doesn’t disappear as children grow older and leads to less education, higher rates of divorce and substance abuse and more time in jail, according to a study published in the Archives of General Psychiatry last month.