Early behavioral markers for neurodevelopmental disorders in the first 3 years of life: An overview of systematic reviews.

Being able to recognize red flags for neurodevelopmental disorders (NDD) is crucial to provide timely intervention programs. This work aims to support - within a scientific framework - the construction of an instrument capable to early detect all spectrum of NDD and explore all areas of development, detect failures in typical developmental pathways and point out atypical signs at all ages. This overview of reviews provides evidence for differences in children later diagnosed with NDD compared to typically developing peers such as delays in motor, language development and temperament in the first three years of age, repetitive/stereotyped behaviors, atypicalities/delays in play, object use, attention, visual, sensory processing and social engagement in the first and second year, and difficulties in feeding and sleeping in the first year. These behaviors must be carefully observed as potential red flags for NDD. However, data of the systematic reviews are not yet useful to develop an evidence-based clinical screening. It urges to increase efforts in producing systematic reviews on early behavioral markers for each NDD. Trial registration:CRD42019137731. (https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=137731).