ADHD Drugs May Not Help with Homework, Cause Heart Arrhythmia

Giving stimulants to kids with attention deficit hyperactivity disorder (ADHD) may not help them complete homework and increases risk of abnormal heart rhythms.

A recently published study has found that giving stimulants to kids with attention deficit hyperactivity disorder (ADHD) may not help them complete homework or get better grades. The study tested the effectiveness of medication against behavioural interventions in 75 children that attended a summer school program for eight weeks. “Long-acting stimulant medications haven’t been shown to help with homework performance despite companies advertising their utility for homework time,” said lead study author Brittany Merrill, a researcher at the Center for Children and Families at Florida International University. “Behavioural interventions are more effective than long-acting stimulant medications in improving homework performance among children with ADHD, and stimulant medication did not add to the effectiveness of the behavioural intervention.”

The children in the study ranged from 5 to 12 years old. Children were randomly assigned to receive either behavioural treatment that included daily report cards for kids and coaching parents to help with homework or a long-acting stimulant. In the group assigned to receive medication, children were assigned to either a stimulant or a placebo for three weeks, then switched, so researchers could see how drugs impacted each child’s homework performance. For the group assigned to behavioural therapy, clinicians led a series of six 2-hour group sessions over the first two weeks, followed by an individual half hour session during each of the next two weeks.

Medication had no significant effects on homework completion or accuracy, compared with a placebo. With behavioural treatment, children got 10 percent to 13 percent more homework problems finished and completed 8 percent more problems accurately than they did without the treatment. This translated into the difference between getting an average passing grade of C with behavioural help, compared with an average failing grade of F without intervention.

One of the limitations of the study was that even with long-acting drugs, the effects might wear off for children who took medication first thing in the morning then didn’t do homework until that night. So by evening when the effect of the medication had dissipated, behavioural interventions would be even more important to help the child get through evening homework tasks.

In clinic, parents often mention this disparity, that teachers say that their children are performing better at school, but parents do not see the same benefit at home. By the evening when parents need to sit down with the children to do homework, the effect of the medication is wearing off.

In another study, the stimulant methylphenidate (Ritalin, Concerta and other brands), appears to increase the risk for arrhythmias, particularly in children and young people with congenital heart disease. In this Australian study, investigators at the University of South Australia, in Adelaide, found that methylphenidate increases the risk for arrhythmias by more than 60% overall and that the risk more than triples for individuals with congenital heart disease. Children on these medicines should have their blood pressure and heart rate monitored to help reduce potential risk.

To explore potential links between methylphenidate use in children and young people and cardiovascular events, the researchers examined data from the South Korean national health insurance claims database for the period 2008-2011. They identified all patients aged 17 years or younger for whom at least one ADHD diagnosis had been recorded. All patients had been receiving methylphenidate and had had a cardiovascular disease event. Cardiovascular events were defined as arrhythmias, hypertension, myocardial infarction, ischemic stroke, and heart failure. The investigators identified 1224 individuals who experienced a cardiovascular event. These events included 864 cases of arrhythmia, 396 cases of hypertension, 52 cases of myocardial infarction, 67 cases of ischemic stroke, and 44 cases of heart failure.

The mean duration of methylphenidate exposure was 0.5 years for all events except heart failure, for which the mean duration of exposure was 0.3 years. Across all risk periods, there was a significantly increased risk for arrhythmia, at an adjusted incidence rate ratio of 1.61, rising to 2.01 during days 1-3 after initial exposure. The increased risk was no longer significant after 56 days from the start of treatment.