A jury will hear from a string of experts this week as to whether they think Dickason was so mentally disturbed when she killed her children that she cannot be held responsible - or if she became so angry she snapped and murdered them.
Dickason, 42, is charged with murdering Liané - who was a week off her 7th birthday - and 2-year-old twins Maya and Karla at their Timaru home in September 2021.
The family had emigrated from South Africa and been in New Zealand less than a month when the girls died.
While Dickason admits she killed the children she has pleaded not guilty to the murder charges by reason of insanity or infanticide.
She is on trial in the High Court at Christchurch before Justice Cameron Mander and a jury of eight women and four men.
The Crown alleges Dickason murdered the children in a “calculated” way because she was frustrated, angry and resentful of them.
It acknowledges Dickason suffered from sometimes-serious depression, it maintains she knew what she was doing when she killed the girls.
The defence says Dickason was a severely mentally disturbed woman in the depths of postpartum depression and did not know the act of killing the children was morally wrong at the time of their deaths.
Further, it says she was “in such a dark place” and had decided to kill herself and felt “it was the right thing to do” to “take the girls with her”.
Experts are now being called to give evidence about Dickason - three for the defence and two for the Crown.
Defence expert grilled by Crown about timing of interview, assessment with accused
Last week, Dr Susan Hatters-Friedman - a global expert on forensic and reproductive psychiatry - gave evidence for the defence.
She explained at length to the jury all the information she had considered to come to a formal conclusion about Dickason’s mental state at the time of the killing.
She interviewed Dickason four times in May and August this year, for a total of 10 hours.
“It is my opinion that at the time of her alleged offending Lauren Dickason was labouring under a disease of the mind to such an extent that it rendered her incapable of knowing that the act was morally wrong. She conceptualised that [killing the children] was the right thing to do.”
Crown Prosecutor Andrew McRae then began his cross-examination of the expert - which continued today.
He questioned Hatters-Friedman about the lateness of her interactions with Dickason.
He put to her that the time between the girls’ deaths and her speaking with Dickason was “a weakness … in terms of being able to get a really clear diagnosis”.
Hatters-Friedman agreed it would have been “optimal” for her to have seen DIckason sooner.
However, the information she was provided together with Dickason’s police interview enabled her to use her “clinical judgement and skills” to come to her conclusion.
“No thought disorder … Focus and concentration were reasonable.”
On September 23, a clinical report was completed for Dickason.
In that, again, it was noted the accused was not delusional.
“Presents with major depressive episode of high severity, no psychotic symptoms,” it said.
“Assessment and plan - Lauren presents with severe depression, I continue to see no strong evidence of psychotic features although I remain open to this.”
On September 28, the psychiatrist saw Dickason again.
“No indication of any disorganisation of thought … or disassociated phenomena,” he wrote.
On October 1, the psychiatrist noted: “Lauren denied any sense of … dissociative phenomena.”
Three days later he noted: “There remains no indication of any disassociative or psychotic phenomena.
“She continues to present with a major depressive episode without indication fo prominent psychotic features.”
McRae referred to a number of other clinical reports - up to more than a month after the alleged murders - where delusions or prominent psychotic symptoms were not noted.
Dickason was on “a very low dose” of antipsychotic medication at the time but the dose later increased.
Hatters-Friedman said she considered all of the clinical notes when making her assessment of the alleged murderer.
She said the notes said things like “no clear evidence” and “without overt psychotic features” the psychiatrist had “kept his mind open”
“She certainly doesn’t present as someone who is obviously psychotic in a very clear way,” Hatters-Friedman
“That’s why it’s really important that they’re paying attention to the more subtle things.”
McRae said sure the doctor who saw Dickason “in person” and a number of times close to the alleged murders would be “best placed” to make the assessment.
Hatters-Friedman agreed but asserted again her belief that his mind was “open” to Dickason being psychotic.
Further, she said “a pair of fresh eyes is able to look at things differently”.
Crown questions expert’s conclusion of ‘psychosis’
McRae put to Hatters-Friedman that if Dickason truly did hold “delusional beliefs” she would be telling others about them.
He said there was no evidence of Dickason doing that.
While it was claimed she was desperately worried about her children’s safety in New Zealand - she mentioned it to no one.
She had “an outlet for her deepest thoughts” in one friend, but said nothing to her.
“She’s not going out there and saying to the teachers … what can I do to protect my child better, and expressing those [concerns] to those around her,” said McRae.
“You’re saying that these things had reached the point of being delusions - they were fixed false beliefs in her mind. If that was the case she would be out there talking to people if that was the case wouldn’t she?”
Hatters-Friedman said that was not necessarily true - Dickason was “a doctor, a smart woman” who was “careful about how she comes across to other people”.
But McRae said the accused was “functioning at a high level” the day she killed the children - making sure their school bags were packed and hair done “immaculately”.
She managed emails and other family admin.
That, he said, was not indicative of a woman spiralling into deep psychosis.
“To get to such a level that would mean she was not able to determine her actions were not morally correct - those delusions would need to be at a level she was absolutely preoccupied,” McRae posed.
Stress had ‘nothing to do with childbirth’ - Crown
McRae suggested that after her arrest Dickason was able to “reform” her memory of killing her children to fit the narrative of delusions.
He also put to Hatters-Friedman that her mental state at the time had nothing to do with childbirth and she could not rely on infanticide as a defence.
He said before Dickason moved to New Zealand she had embarked on a wellness programme which had resulted in weight and centimetre loss, regular exercise, her stopping “binge eating” and feeling less “sad” in her mind.
She told people that as a result of feeling better, she had stopped taking her antidepressant medication - the first time in a decade she’s been off it.
McRae said the depression and postpartum depression she’d battled with was, as evidenced by her own comments, “in remission”.
He said any stressors she was struggling with from July when the family’s emigration journey intensified - were “very new”.
He said the stressors had nothing to do with childbirth.
“There has to be a point where there is no aspect of the childbirth cause - and new stressors have taken over that mantle and created the depression that caused difficulty for Ms DIckason,” he said.
McRae said a Crown expert would indicate that Dickason had “fully recovered from depression associated with effects of giving birth” and was “in full remission of symptoms.
The expert will tell the court Dickason’s depression at the time of the alleged murders “could not be the result of ‘not having fully recovered from giving birth to her children’.
“This isn’t a case where the cause is one that derives from childbirth,” McRae posed to Hatters-Friedman.
She replied: “It is my opinion that it’s related to childbirth and reproduction”.
“She has this long history of many reproductive-related depressions, then she stops her medication… then she has all these awful stressors,” the doctor said.
“The depressive history that she has, the coming off medication, the coming off medication leads to an increase in depression again.