ORIGINAL ARTICLE Apnea-hypopnea indices and snoring in children diagnosed with ADHD: a matched case-control study Barbara C. Galland & E. Gail Tripp & Andrew Gray & Barry J. Taylor # Springer-Verlag 2010 Abstract Objectives To measure apnea-hypopnea indices and snoring in children diagnosed with attention-deficit hyper- activity disorder (ADHD) in a case-control design. Addi- tionally, the study design allowed us to investigate whether or not methylphenidate had any effect on breathing variables. Methods Twenty-eight children (22 boys) aged 6–12 years meeting diagnostic criteria for Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV ADHD were studied together with matched controls. Two nights of polysomnography (PSG) were conducted that included recordings of snoring waveforms. A randomly assigned 48-h on-off medication protocol was used for ADHD children. Control children’ s recordings were matched for PSG night, but medication was not used. A low apnea- hypopnea index (AHI) threshold of >1event per hour was used to define sleep-disordered breathing (SDB) because of a clinical relevance in ADHD. Results Categorical analyses for paired binary data showed no significant differences between control and ADHD children for presence of an AHI >1 or snoring. Variables were extracted from a significantly shorter total sleep time (67 min) on the medication night in children with ADHD. Eight (28%) control and 11 (40%) ADHD children snored >60 dB some time during the night. Methylphenidate had no effect on central apneas, AHI, desaturation events, or any snoring data. Conclusions Our PSG findings show no strong link between ADHD and SDB although our findings could be limited by a small sample size. Findings from PSG studies in the literature argue both for and against an association between ADHD and SDB. Our results suggest medication is not a factor in the debate. Keywords Attention-deficit hyperactivity disorder . Snoring . Methylphenidate . Polysomnography Introduction Attention-deficit hyperactivity disorder (ADHD) is the most common behavioral disorder of childhood with prevalence figures ranging from 4% to 12% amongst 6–12 year olds (reviewed in [1]) with a male to female ratio ranging from 4:1 to 9:1 [2, 3]. The disorder is characterized by developmentally inappropriate levels of inattention, impul- sivity and over-activity that form the core symptoms of the disorder. Comorbidities include poor academic perfor- mance, disruptive social interactions, diminished self- esteem, and significant behavioral disturbance. In addition to its effects on child functioning, ADHD also impacts negatively on those closest to the child in all environs. The condition can persist into adulthood and is associated with high levels of morbidity and disability. There appears to be an overlap between sleep problems and ADHD, as acknowledged since 1980 when the Diagnostic B. C. Galland (*) : B. J. Taylor Department of Women’ s and Children’ s Health, University of Otago, P.O. Box 913, Dunedin, New Zealand e-mail: barbara.galland@otago.ac.nz E. G. Tripp Department of Psychology, University of Otago, Dunedin, New Zealand A. Gray Department of Preventive and Social Medicine, University of Otago, Dunedin, New Zealand DOI 10.1007/s11325-010-0357-0 Sleep Breath (2011) 15:455–462 Received: 18 February 2010 / Revised: 12 April 2010 / Accepted: 18 April 2010 / Published online: 4 May 2010