DENVER – Adolescents with symptoms of sleep-disordered breathing had a 2.5-fold increased prevalence of inattention-type attention-deficit hyperactivity disorder in the first large, population-based study to examine this relationship, Eric O. Johnson, Ph.D., reported at the annual meeting of the Associated Professional Sleep Societies.
In contrast, sleep-disordered breathing (SDB) was not linked to hyperactivity-type ADHD in the survey of 1,014 Detroit-area youths aged 13–16 years and their parents, according to Dr. Johnson of the Henry Ford Health System, Detroit.
The observed association between SDB and inattention-type ADHD was independent of potential confounders including race, body mass index, the presence of conduct or oppositional defiant disorder, and asthma.
Participants were randomly selected from a large Detroit-area HMO. Computer-assisted structured interviews conducted separately with the teenager and one parent showed good concordance with regard to the presence of SDB.
Roughly 6% of the adolescents experienced the classic symptoms of loud snoring, periods of stopped breathing, and/or choking or gasping sounds during sleep at least once a week. The prevalence of SDB symptoms was twice as high among African American teenagers as among whites.
By the adolescents' own reports, 4.5% met DSM-IV criteria for lifetime diagnosis of ADHD. By their parents' accounts, the rate was 7.8%. Most cases were of the inattention type. Through use of the statistical tool known as generalized estimating equations, it was possible to account for the differing parental and adolescent estimates and essentially split the difference.
Although this was the first large, population-based study to examine SDB and ADHD in a teenage population, several small, clinic-based studies have suggested that SDB in young children is associated with both hyperactive- and inattention-type ADHD. Obstructive sleep apnea in adults is typically associated with inattentive types of behavior rather than hyperactivity.
The new Detroit survey suggests that by the time children with SDB reach the age of 13–16, the dominant manifestation has shifted from hyperactive- to inattentive-type behaviors for many individuals.
But it must be emphasized that in a cross-sectional study it's impossible to assign causality; that is, it's unclear from these data whether SDB causes inattention or whether inattentive-type ADHD somehow predisposes individuals to SDB, Dr. Johnson noted.
The study was funded by the National Institutes of Health.