Source hospital and asylum records
Data protection issues often complicate the search for hospital records from the 20th century. However, as long as you can provide proof that the individual concerned is no longer alive, it is possible for the archive to access the records and provide copies of the pertinent section even if a catalogue entry states that the records are closed. Search for details of holdings via The National Archives’ catalogue discovery.nationalarchives.gov.uk or its (no longer updated) Hospital Records Database at nationalarchives.gov.uk/hospitalrecords, then get in touch with the archivist to ask if a copy can be made of any material with details of your ancestor.
Also the Wellcome Library has digitised a number of records relating to mental healthcare, including many that span the whole of the 20th century ( bit.ly/ wellcome-mental). Patient records only go up to 1913 online, but there are staff photos, magazines, minutes and other records going all the way up to 2000.
This photograph of the Gartnavel Royal Hospital bowling club is from the Wellcome Library's online collection