Parents of children with attention deficit hyperactivity disorder (ADHD) have long reported that their kids have a great deal of difficulty settling into bed and falling asleep. Until now, however, scientific studies that measure sleep quality through electrodes have failed to show a correlation between sleep quality and ADHD.
Now a new study by Aarhus University in Denmark scientifically confirms the parental reports — that children with ADHD do, in fact, get poorer sleep compared to other children.
“Our study will confirm what many parents have experienced, which is that children with ADHD take longer to fall asleep at night,” says study leader Anne Virring Sørensen Ph.D., from Aarhus University and medical doctor at the Child and Adolescent Psychiatric Hospital, Risskov.
“With our measurements we can also see that these children experience more disturbed sleep including less deep sleep. If you only look at length of sleep, children in the ADHD group sleep for 45 minutes less than children in the control group.”
The study involved 76 children with ADHD (average age 9.6 years) and a control group of 25 children without ADHD. The researchers conducted outpatient sleep examinations with electrodes during the night (polysomnography) as well as several sleep latency tests which measured how quickly the children fell asleep.
Two in three children with ADHD have one or more additional psychiatric diagnoses on top of ADHD, which may increase the risk of sleep problems. But even when the researchers look at the children with only ADHD, they see a big difference in the sleep patterns of the control group and the ADHD group.
The researchers found surprising results related to daytime sleeping patterns as well. “Unlike in the evening we could see that there was a tendency for the children with ADHD to fall asleep faster during the day than the children in the control group. This is somewhat surprising when you take into account that ADHD is associated with characteristics such as hyperactivity. But this hyperactivity could be compensatory behaviour for not being able to doze off during the day,” says Sørensen.
The fact that researchers have not previously been able to show a link between ADHD and poorer sleep could be due to different measuring methods.
“In our study the children had electrodes attached to their heads for what is known as a polysomnography at the hospital in the afternoon, but they slept in their familiar home surroundings. In previous studies children have been admitted to specialist sleep centres at hospital to measure sleep via a polysomnographic study,” says Sørensen.
While many children with ADHD are given medicine to help them fall asleep, Sørensen emphasizes that none of the children received medicine while taking part in the study. She believes that the study is important in both the short and long term.
“I think many parents and clinicians are very pleased to receive confirmation that poor sleep patterns can now be demonstrated and that there is probably a correlation with the ADHD diagnosis. The next step is, of course, to find out where this correlation lies so we can develop better treatments in the long term. Our survey is an important foundation for further studies,” she says.
The study was recently published in the Journal of Sleep Research.
Source: Aarhus University