A female patient at Rampton Secure Hospital who can rarely leave her room repeatedly punched a nursing assistant without warning, a court heard.
Elehah Etemadi launched the attack on July 6, last year.
Prosecutor Kate Beardmore said: “The defendant was sitting outside and said she felt mentally unwell. She was encouraged to go back into the hospital.
“She refused to do that. She punched the nursing assistant in the left side of her body four times, then four times more before other staff could assist.”
The nursing assistant was left with bruising and discomfort, but no lasting injuries.
Jill Hawkins, mitigating, said Etemadi has been at the hospital for more than five years and is currently on the high-intensive psychiatric Emerald Ward.
“She is very rarely brought out of her room because there are incidents like this,” she said.
“She is self-harming on a daily basis. I think the future for her is fairly bleak. There are no plans to move her from Rampton.”
She said Etemadi’s ESA had been suspended, but staff didn’t know why.
Etemadi, 35, admitted the assault via her solicitor, at Mansfield Magistrates Court, on Friday.
She was ordered to pay compensation of £150 and costs of £85 from her savings.