Final answer:
Developmental disorders commonly emerge during sensitive periods of development, especially infancy and early childhood. This time is crucial for reaching developmental milestones, where any atypical progress can signal the presence of disorders such as ASD or ADHD.
Step-by-step explanation:
Developmental disorders usually appear during certain critical periods of a child's development, such as infancy and early childhood. During these times, different parts of the nervous system are developing, making these stages more sensitive to disturbances that may lead to neurodevelopmental disorders.
Disorders like Autism Spectrum Disorder (ASD) and Attention Deficit/Hyperactivity Disorder (ADHD), amongst others, exhibit complex symptoms that can include intellectual deficits, communication challenges, learning difficulties, or motor system issues. It is often during the early stages, when developmental milestones are expected to be reached, that discrepancies in development can be observed, indicating potential neurodevelopmental disorders.
The exact timing can vary, as the onset of symptoms is influenced by a complex interplay of genetics and environment, reflecting the distinct course of development for each child. However, the recognition of potential disorders often occurs in early childhood, particularly when children are of school age and display difficulties in learning or behavior which do not correspond to the normative developmental milestones.