Castlebar Mental Hospital 'Lunatic Asylum'

Hello,

Through my research I have found a number of ancestors who have died at what was then the Castlebar Mental Hospital. Their causes of death range from 'religious mania' to 'melancholia' which I know would now likely be different diagnosis'. I can only find a record of their deaths and wondered if anybody knew if there were any sort of records about patients and if so, where could they be found?

Thanks in advance!