A scientometric analysis investigating melatonin and cortisol in the context of sleep in autism

Sleep disturbances are extensively reported in Autism Spectrum Disorder (ASD) but the nature of this association is, to date, unclear. This study uses a scientometric methodology to explore the role of two key biological factors, namely melatonin and cortisol, including its precursor adrenocorticotropic hormone on sleep. Six hundred and thirty-four papers were retrieved from Scopus. A co-citation analysis was carried out, from which ten thematic clusters were identified and discussed chronologically, these were: “Epilepsy” (average year of publication = 1998), “Biology of sleep” (average year of publication = 2001), “Paediatric sleep” (average year of publication = 2001), “Sleep in ASD” (average year of publication = 2003), “Co-occurring conditions” (average year of publication = 2007), “Psychopharmacology, ASD and sleep” (average year of publication = 2007), “HPA-axis dysregulation” (average year of publication = 2009), “Use of melatonin for sleep disturbances in ASD” (average year of publication = 2013), “Safety of melatonin medications for sleep in ASD” (average year of publication = 2015), “Disturbed sleep in children, a symptom in a bigger picture” (average year of publication = 2016). Detailed analysis of each cluster indicated that the association between ASD and sleep is complex and multifactorial. As such, two main areas for future research were identified: (a) the need for larger studies that allow stratification of the population to uncouple confounding factors (e.g. concomitant use of medications) and (b) the need for longer, longitudinal studies assessing melatonin and cortisol in ASD across development.