A lifelong abuse of cannabis likely triggered the schizophrenia that led Cairns mother Raina Thaiday to murder eight children, a court has found.
Justice Jean Dalton last month ruled in Queensland's Mental Health Court that Thaiday suffered a psychotic episode when she killed her four sons, three daughters and a niece at the family's Manoora home on December 19, 2014.
The court heard the 37-year-old was of "unsound mind" at the time of the attack and believed she was saving the children, aged between two and 14 years, from the end of the world.
Several psychiatrists agreed Thaiday's persistent cannabis abuse triggered her schizophrenia despite the illness usually manifesting in the younger years of life.
In the months before the massacre, Thaiday was smoking up to 20 cones of cannabis a day.
Her illness brought on an obsession with cleansing and prompted her to give up drugs and alcohol but by then her delusions had "a life of their own".
The night before the murders, neighbours reported seeing Thaiday pacing back and forth talking to herself or on the phone that in hindsight were clearly psychotic.
"I have the power to kill people and to curse people," Thaiday said.
"You hurt my kids, I hurt them first. You stab my kids, I stab them first. If you kill them, I'll kill them."
Treating psychiatrist Angela Voita told the court Thaiday had poor insight into her illness and was reluctant to take medication.
Dr Voita said while she was currently stable, Thaiday was able to hide her more subtle symptoms from those who did not know her well, and could be violent to herself and others if not medicated.
Justice Dalton ordered Thaiday continue to receive involuntary treatment and be allowed escorted leave on the grounds of the high-security health facility where she is being held.
Readers seeking support and information about suicide prevention can contact Lifeline on 13 11 14.
Suicide Call Back Service 1300 659 467.
Multicultural Mental Health Australia www.mmha.org.au.
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