Final answer:
The common feature across all neurodevelopmental disorders is impaired brain function, which stems from a combination of genetic, environmental, and sometimes unknown factors disrupting the development of the CNS. These disorders come with complex symptoms and difficulties in diagnosis and treatment.
Step-by-step explanation:
The common feature across all childhood neurodevelopmental disorders is impaired brain function. Neurodevelopmental disorders can result from various factors, including but not limited to genetic mutations, brain injury, and environmental toxins. The disorders are complex, with many cases involving a combination of factors that disturb the normal development of the central nervous system (CNS). These disorders have been associated with intellectual deficits, communication and learning challenges, as well as complex symptoms as seen in autism spectrum disorder and attention deficit/hyperactivity disorder.
Neurodevelopmental disorders are challenging to define precisely because they often involve a blend of genetic, environmental, and sometimes unknown factors that disrupt the CNS's development. These factors can collectively impair brain functions in complex ways that are not immediately visible, such as improper connections between brain regions without any outward defect or damage, making diagnosis and treatment challenging.