Mental Retardation Causes More Condition_symptoms Do Adults Get Mental Retardation From Things Other Than Childhood Causes?

Do adults get mental retardation from things other than childhood causes? - mental retardation causes more condition_symptoms

I read that some people say, mental retardation occurs in lead-based. Well, when I grow up, if people take drugs and not to test for the assignment or work or even on the IQ test, does that mean they are mentally disabled?