Victoria's high-security mental health hospital is at "crisis point", with a waiting list of up to a year for prisoners with significant mental health issues, a court has heard.

One of those waiting for a bed at Thomas Embling, in Melbourne's north-east, is a man facing arson charges who was excused from facing the Victorian County Court after corrections staff reported he was acting in a disturbed manner.

Christopher Keane has been in custody since last August.

His lawyer Aime Hancock told the court Keane has been certified but was told he would have to wait six to 12 months to be admitted to Thomas Embling psychiatric hospital due to a lack of beds.

"They described the next person on the waiting list as not eating and if they don't go in they could die," she said. "They're at crisis point."

Ms Hancock told the court her client had started refusing medication for his mental health.

"There could be quite a quick turn around in his mental health," she said.

"But until he receives the treatment he needs it may not improve. Due to the lack of resources at Thomas Embling, we're stuck."

Ms Hancock said if Keane was in the community and acting in a similar manner, he would likely be immediately admitted to Thomas Embling as an involuntary patient.

Keane was unable to enter a plea at the hearing due to his mental state.

The court ordered further psychiatrists reports before a decision is made on how to proceed with his case.