Parent stabber mentally ill, court hears

A young man accused of stabbing his parents in their Sydney home may have a long-term psychiatric illness, a court has heard.

David Anderson, 21, was reportedly on the drug "ice" when he allegedly attacked his mother and father at Oatlands in the city's northwest in January.

The man's legal proceedings may be complicated by a psychiatrist's report finding the man suffers from a psychiatric illness, a Parramatta Local Court heard on Thursday.

"The problem affecting Mr Anderson isn't said to be a short-term thing," Magistrate Timothy Keady said.

Mr Anderson's parents, both in their fifties, were treated in hospital for injuries sustained during the alleged attack, which happened in the early hours of January 22.

Their son is facing a string of charges, including one count of causing wounding with intent to commit murder relating to his father.

He is also charged with using a carriage service to threaten to kill his father on Boxing Day last year.