Objectives: To measure apnea-hypopnea indices and snoring in children diagnosed with attention-deficit hyperactivity disorder (ADHD) in a case-control design. Additionally, 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 >1 event 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.