1. A method of treating a child with a mental development disease, comprising the steps of: testing and observing a nonverbal development stage and a verbal development stage of said child; determining said verbal development stage and said non-verbal development stage of said child; and administering a therapeutic dosage of a dopamine agonistic medicine to said child upon said child being determined to demonstrate an equivalent 18 to 24 month development level with either said verbal development stage or said non-verbal development stage.