Michael Parsonage, 51, was sent to Three Bridges regional secure unit under section 37 of the Mental Health Act without limit of time. He had pleaded guilty in June to the manslaughter of his wife, Carole, 50, at their home in east Finchley, north London, last November, on the ground of diminished responsibility.
At the Old Bailey in London, Judge Geoffrey Grigson told Parsonage yesterday: "This was a truly tragic case." He said Parsonage had been suffering from a severe depressive illness at the time of the attack and psychiatric reports showed he was still ill and needed treatment.
The court was told that Parsonage had been tormented by guilt over his affair with a Treasury colleague. A forensic psychiatrist, Nadji Kahtan, said Parsonage still presented a risk to the public and in particular to his mistress. Dr Kahtan said: "He is an urbane and intelligent man and it is easy to forget what he is capable of doing in a disturbed mind."
Diana Ellis, for the defence, said Parsonage had suffered permanent leg and brain injuries from his failed suicide attempt and could not remember what had happened.
Oxford-educated Parsonage had met Carole, his second wife, at university and the marriage had been happy for a number of years, Ms Ellis said. But doctors now confirmed that he had the type of personality that would lead him into depression in middle age.
Close friends and family suspected a change in him in the past two or three years. He had become more withdrawn. In November, Mrs Parsonage took him to see the crisis psychiatric team at Barnet General Hospital, north London. But "regrettably", a junior doctor sent him home with tranquillisers, Ms Ellis said.
Mrs Parsonage had told the doctor that her husband was paranoid and delusional - thinking she, or his colleague, would kill him. Mrs Parsonage was apparently killed while she was trying to phone the hospital again, and her body was found the next evening. She had many skull fractures.