A Kensington mental health worker was left unable to return to work after she was kicked and grabbed around the throat by a patient.
Akbar Ali, 20, admitted assault by beating after lashing out at Deborah Banton while receiving treatment at a centre in Kingsbridge Road, North Kensington.
On Thursday, West London Magistrates' Court heard that Ali entered an area of the centre that was off-limits to him on January 23 this year.
Tom Gill, prosecuting, said: "Deborah Banton asked him to leave as he should not be there. He told her to shut up or he would punch her in the face."
He added that Ali then kicked Ms Banton in the stomach three times before he managed to grab her around the throat, making it hard for her to breathe.
Mr Gill said: "She left work and saw her GP. She had no bruising but she was afraid of his threats of violent behaviour in the past. The main injury is psychological as the victim has not returned to work."
Ali's defence lawyer said he was staying at Schomberg House, in Page Street, Pimlico, where he was receiving help with his mental health problems.
Presiding magistrate Mrs Jenkins adjourned sentence until April 2 for reports to be prepared by the probation service.