Hi ,
Welcome to Rootschat

Newspapers are a good source of info
Yorkshire Post and Leeds Intelligencer 2nd Nov 1939
"National registration figures made available yesterday have revealed the population of Aireborough is 24224.Included in this is 2225 inmates at the West Riding Mental Hospital at Menston."
Also applications invited for various tenders...
West Riding Mental Hospitals, Menston nr Leeds, Storthes Hall Kirkburton nr Huddersfieldand and Wadsley Bridge nr Wakefield.
A 1936 entry has High Royds Hospital , Menston Road, Menston.
So still not quite sure if the same hospital but I m sure someone else might know.
Cathy