ADHD Linked to Lack of Sleep in Kids

Lack of sleep in children increases their risk of developing attention deficit hyperactivity disorder (ADHD), according to new research published in the April 27, 2009 online edition of Pediatrics. In a study of 7- and 8-year-olds conducted by researchers at the University of Helsinki in Finland, children who received less than 7.7 hours of sleep per night were at significantly increased risk of developing hyperactive/inattentive disorders compared to children who slept longer. The Finish study is the first to identify length of sleep alone as a source of behavioral difficulties.

“There is a large amount of literature linking sleeping difficulties to behavioral symptoms,” principal researcher E. Juulia Paavonen, M.D., Ph.D. told Medscape Psychiatry in an April 28, 2009, online article about the study. “However, this study shows short sleep duration itself is related to behavioral symptoms, independent of sleeping difficulties.”

The study provides a potential key for the treatment of rising attention and cognitive performance issues among U.S. children. As many as one-third of American children do not receive an adequate amount of sleep.  While previous studies have indicated a probable link between sleep disorders, such as sleep apnea, and the behavioral symptoms associated with ADHD, none of those studies included behavioral assessments. The Finish study is the first to specifically assess the effects of sleep length on behavioral issues in children and show a definite causal effect between lack of sleep and decreased attention span and cognitive performance.

The study evaluated the sleep habits and duration of 280 boys and girls with a mean age of 8.1 years. Assisted by the children’s parents, sleep journals logged when children went to bed, woke up and were allowed to leave their beds over seven-day intervals. Problems such as illness that could affect sleep quality were also recorded. Hyperactivity, impulsivity and inattention symptoms were evaluated using the maternal ratings from the ADHD Rating Scale. Socioeconomic status, parental education and other demographic data were also considered. The majority of the test group (80.7%) were categorized as average sleepers, getting 7.7 to 9.4 hours of sleep per night. Short sleepers (9.3%) received less than 7.7 hours of sleep, while long sleepers (10%) got more than 9.4 hours of sleep.

Next time: Study recommendations: What parents can do.