The death of a five-year-old boy stabbed 76 times by his father has prompted recommendations about heightened availability of mental health services within the community.

The child, known for legal reasons as JY, was stabbed by his father and died at Westmead Children's Hospital on the morning of June 8, 2018.

An autopsy found stab wounds on the boy's chest, arms, and legs as well as scattered bruises on his legs.

JY was born in 2012. He enjoyed spending time at his grandfather's workshop, developed a keen interest in cars, loved spending time with his family and was popular in his neighbourhood.

"The circumstances of JY's death were tragic, but his life was filled with love and joy," NSW State Coroner Teresa O'Sullivan said in findings published on Wednesday.

Diagnosed with schizophrenia in 2003, the father, known only as BS, used both medication and therapy to treat his mental health condition.

He voluntarily admitted himself to hospital numerous times when his mental health deteriorated.

This included a period at Hornsby Hospital in April and May 2018 after he began referring to himself as God and experienced delusions about the devil.

He was eventually discharged and put into the care of a community mental health team.

On June 8, 2018 at Westmead, he experienced an acute psychotic episode and stabbed and killed his son.

Arrested and tried for the offence of murder, the NSW Supreme Court found BS not guilty by reason of mental illness in July 2019.

Ms O'Sullivan found the deterioration in his mental health was caused by non-compliance with his anti-psychotic medication regime as well as psycho-social stressors like housing arrangements and financial stress.

While medication was changed at Hornsby, information given to the community health team was ambiguous and incomplete, and there was some confusion about how to treat BS in future.

His mental state worsened in the weeks before JY's death, and he experienced "auditory hallucinations and paranoid thoughts (and a) male voice asking him to have (a) boxing match with himself".

Two days before the stabbing, he also referred to his son as "the devil". The boy's mother expressed concern that her husband could "snap" and kill the child.

While finding BS should have been referred to a doctor at that point, Ms O'Sullivan said any risk of violence could not have been predicted.

The family would not have left the father and son alone at the hospital if they were aware of any risks he posed, she said.

Ms O'Sullivan recommended the NSW government's REACH program be expanded to community mental health settings, making it more consistently available.

She suggested consumers, families and carers be provided with sufficient information about how to utilise the program, which aims to provide an easy way to escalate any concerns about worrying changes in a patient's condition.

"It appears to me that the success of the REACH program depends upon patients and carers being aware of its existence and how to use it, in addition to mental health clinicians recognising when patients or carers are seeking to invoke REACH," she wrote.

Other key changes for the provision of accurate information regarding patients between hospitals and community health teams have already been brought in as a result of the incident.

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