A new research suggests that attention-deficit/hyperactivity disorder (ADHD) medication may have an adverse effect on children's sleep.

Researchers from the University of Nebraska-Lincoln found that stimulant medications for ADHD cause sleep problems among the children who take them. The study addresses decades of conflicting opinions and evidence about the medications' effect on sleep.

"We would recommend that pediatricians frequently monitor children with ADHD who are prescribed stimulants for potential adverse effects on sleep," Katie Kidwell, lead author of the study, said in a statement.

For the study, researchers reviewed nine studies that required objective measures obtained through clinical sleep studies or wristband monitors used at home.

They found that both methylphenidate medications like Ritalin and amphetamines like Adderall cause sleep problems, without identifying differences between the two. Although they were unable to determine whether varying dosage amounts changed the effect on sleep, they found that more frequent dosages made it harder for children to fall asleep.

They found that drugs tend to cause more sleep problems for boys. The problems dissipate, but never completely go away, the longer children continue to take the medication.

"Sleep impairment is related to many cognitive, emotional and behavioral consequences, such as inattention, irritability and defiance," Kidwell said. "Sleep adverse effects could undermine the benefits of stimulant medications in some cases. Pediatricians should carefully consider dosage amounts, standard versus extended release, and dosage frequencies to minimize sleep problems while effectively treating ADHD symptoms."

Kidwell also recommended considering behavioral treatments, such as parental training and changes to classroom procedures and homework assignments, to reduce ADHD's negative consequences.

"We're not saying don't use stimulant medications to treat ADHD," researcher Timothy Nelson said in a statement. "They are well tolerated in general and there is evidence for their effectiveness. But physicians need to weigh the pros and cons in any medication decision, and considering the potential for disrupted sleep should be part of that cost-benefit analysis with stimulants."

The findings are detailed in the journal Pediatrics.