Sometimes Biology Trumps Good Sleep Hygiene
A first-of-its-kind study has discovered that melatonin rhythms differ between children with autism and children without the disorder. This discovery could explain why sleep problems are prevalent in children with autism and why, even after appropriate sleep hygiene protocols are established, individuals with autism still struggle to get a good night’s sleep. To conduct this research, a team of Spanish scientists evaluated melatonin rhythm and its relationship with sleep and circadian parameters in children and adolescents with autism. Their cross-sectional study involved 41 children and adolescents with autism and 24 neurotypical children and adolescents. All participants were matched for sex, body mass index, and pubertal stage. None of the study’s participants took sleep-inducing drugs. Circadian and sleep parameters were analyzed using an ambulatory circadian monitoring (ACM) device. Saliva samples were also collected around sleep onset to determine dim light melatonin onset (DLMO). In short, DLMO is a natural occurrence where the human body produces its own melatonin starting two hours before bedtime, providing the lighting is dim. The study found that prepubertal individuals with autism presented later DLMO and earlier decline in melatonin during adolescence. Also discovered was a relationship between melatonin and both sleep and circadian parameters. Participants and controls with later DLMOs were likelier to have delayed sleep onset times. Interestingly, the researchers discovered that later melatonin peak time and DLMO time were related to lower general motor activity and lower stability of its rhythms. The authors concluded their study by calling for more extensive, multi-day studies to further explore this relationship.