Cauchi, 40, was experiencing psychotic symptoms in April 2024 when he fatally stabbed six shoppers at Sydney's Westfield Bondi Junction and injured 10 others.
As an inquest into the rampage resumed on Tuesday, the Queensland psychiatrist started her evidence by issuing a tearful apology to the families of the victims, Cauchi, and everyone affected.
"I offer my sincere apologies to you that this tragedy has happened," she said.
"I am aware that no words will ease the profound pain and suffering."
She told the NSW Coroners Court that she had been personally affected by the attacks, which had impacted her life and health.
"No psychiatrist in the world would wish on themselves for this trauma to happen," she said.
Counsel assisting Peggy Dwyer SC will ask the doctor, who cannot be legally identified, about her treatment of Cauchi.
This will include a decision to stop his anti-psychotics in 2019 and what could have been done after Cauchi's mother later raised concerns about a decline in her son's mental health.
Cauchi's mother first raised concerns about her son's worsening symptoms three months after he was weaned off the medication, the inquest was told on Monday.
While he presented well afterwards, potential signs of relapse surfaced, a treating nurse said.
Cauchi's father, however, was "adamant" about his son not resuming anti-psychotics and said "he himself had been traumatised by demons when awake and hears voices and is not on medication," a nurse's note read to the coroner said.
Cauchi had been diagnosed with schizophrenia as a teen but was successfully treated for decades.
Two nurses have already given evidence about Cauchi's treatment, and both have said he did not present with any serious symptoms during appointments.
His mother told them he was hearing voices, expressing sleeplessness, and experiencing extreme obsessive-compulsive disorder.
While the nurses did initial consultations with Cauchi and sometimes his family, it was the psychiatrist who ultimately prescribed his medication and formed a treatment plan.
In early 2020, near the start of the COVID-19 pandemic, he moved to Brisbane.
While some attempt was made to arrange remote appointments, these were not covered by Medicare, the inquest has been told.
A referral letter was sent to Cauchi's GP, but no follow-up was organised with mental health services in Brisbane.
His rampage at the Westfield shopping centre in 2024 was brought to an end after he was shot dead by NSW Police Inspector Amy Scott.
The hearing continues.
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With AAP.
