You are assessing an eight-year-old male child with attention-deflcit/hyperactivity disorder (ADHD)

(D). At first, hypertension, ataxia, and hyperthyroidism should be excluded. Other differential diagnosis should be considered as heavy metal poisoning (including lead), sensory deficits (hearing and vision), auditory and visual processing disorders, and neurodegenerative disorder, especially leukodystrophles. Fragile X syndrome, absence and sleeping disorders are also important differential diagnose