A further Institute of Psychiatry study Psychiatric Aspects of Imprisonment was published outlining the history of prison psychiatric services and the development of Grendon prison.
A study in Grendon prison showed that’s significant psychological change occurs in the therapeutic environment which was not matched by similar prisoners who did not go to Grendon.
Some changes were also noted in Wormwood Scrubs prisoners who received psychiatric treatment of these were not as extensive as the changes shown in Grendon prisoners.