A comprehensive diagnostic evaluation is a detailed assessment that examines an individual's cognitive, emotional, social, and behavioral functioning. It is commonly used to identify developmental delays, autism spectrum disorder (ASD), or other concerns, helping to establish a diagnosis, guide treatment, and connect individuals with appropriate support services. 

Psychological and neuropsychological testing are assessments used to evaluate mental and cognitive functioning. Psychological testing focuses on emotional and mental health, while neuropsychological testing examines cognitive abilities and brain function. Both help diagnose conditions and inform treatment but provide different insights through distinct approaches.