Stephen Bailey, 37, was deemed to be mentally impaired and incapable of knowing his actions were wrong at the time of Penelope Bailey was killed.

Ms Bailey's body was discovered in a creek bed in suburban Donvale in 2015, three days after her son was seen running through traffic in his underwear and arrested.

A Supreme Court judge delivered the not guilty murder verdict in April last year and it was hoped Bailey would be transferred from prison to a psychiatric hospital before long.

But Bailey, who faced court on Friday for an update on the case, remains in a mental health unit at Port Phillip Prison.

His lawyer Amelia Beech said Bailey still suffers "grandiose" psychotic symptoms but he is unable to receive the ideal treatment while in jail.

"Mr Bailey remains not on what was described as the optimum anti-psychotic drug," she told the Supreme Court.

"He has only partially responded to medication. He continues to experience distressing, grandiose psychotic symptoms."

A potentially more effective anti-psychotic drug is available but Bailey can't have it because prison staff aren't equipped to deal with the potential side effects, the court was told.

Bailey continues to wait for a bed at Thomas Embling Hospital forensic mental health hospital.

Ms Beech said more than a dozen beds had been expected to become available by now but they had not.

Bailey had been a fitness fanatic during his football days at VFL club Box Hill and two SANFL clubs in Adelaide.

But in 2011 he started to develop paranoid thoughts, which developed into voices directing his actions, the court previously heard.

Bailey believed a wealthy establishment known as the "Mime Order" controlled him and once told his sister he thought he was Jesus.

The case was adjourned to return to court on June 22.

Australian Associated Press