Sylvester Minogue was Superintendent of the Rydalmere Psychiatric Hospital for five years, until his resignation in August 1947.

Minogue had previously served at Kenmore Mental Hospital, where he aimed to improve the living conditions of patients by increasing the amount of recreation space for patients in the hospital, and reducing the number of padded cells, locked doors and barred windows. He also experimented with new forms of treatment including group therapy, hypnosis, electro-convulsive therapy and new medications. His methods were not embraced by the New South Wales Health Department.

Following his move to Rydalmere, he became interested in the Alcoholics Anonymous organisation, and established the first branch of Alcoholics Anonymous in Australia. The first meeting was held in 1945 at his residence a short distance from the Female Orphan School building.

In 1947, he resigned from his position at Rydalmere in frustration at the way in which mental health patients were treated. At his farewell party he told his staff that:

 “Stupid rules and regulations enforced by the Government and lack of modern facilities, equipment, space and staff made treatment of the insane a hopeless an impossible task. I have been criticised because of my unorthodox views. Every idea I have advanced was neither new or radical, but was based on common-sense and normal developments in other countries...Conditions in mental hospitals in New South Wales are 100 years behind those in other countries. Indeed we have lagged so far behind that I believe we will never catch up. Rydalmere Mental Hospital has space for approximately 800 patients, yet at present, there are over 900 here…Only 34 doctors are attending the 12,000 certified insane people in the whole of New South Wales.” 

He explained that “I have realised that the things I have striven for can never come about so I decided to get out.” One of his major disagreements with the Health Department was his belief that patients were unnecessarily confined – many patients were kept behind barred windows and locked doors, even though it was safe for them to have greater freedom of movement: “I have always determined that the only way to govern patients is by knowing and understanding them. I don’t think they should be locked up”. The press reported that even epileptic and senile patients were kept in these conditions.

Dr Minogue was held in such high esteem that a petition was circulated amongst the staff calling on him to reconsider his decision to resign.

He left the hospital to establish his own private practice in Macquarie Street.