Food additives can cause hyperactivity..I taught a boy who did reacted with certain "E" numbers..although diagnosed and having a clear understanding he would seek out the sweets that caused his behaviour to be out of hand..
he became a world class swimmer when he was channeled into sport.
the condition for him curtails his ability to work so sport fills a social need

Hyperactivity has a different diagnosis to autism which has a name in todays society but would be blanketed in the past when often institutional living was usued to care for the children

The continuim of autusim is vast.