See all of this from Wikipedia. We do not see anything of a similar scope in this case.
"Following the birth of her fourth child, Luke, Yates' depression resurfaced. On June 16, 1999, Rusty found her shaking and chewing her fingers. The next day, she attempted suicide by
overdosing on pills, leading to her being hospitalized and prescribed
antidepressants. Soon after her release, Yates begged Rusty to let her die as she held a knife up to her neck. Once again hospitalized, she was given a plethora of medications, including
Haldol, an
anti-psychotic drug. Yates' condition improved immediately, and she was prescribed it upon her release. After this incident, Rusty moved the family into a small house for the sake of her health. She appeared temporarily stabilized.
[8]
In July 1999, Yates had a
nervous breakdown, which culminated in two suicide attempts and two psychiatric hospitalizations that summer. She was subsequently diagnosed with
postpartum psychosis.
[9]
Yates's first psychiatrist, Dr. Eileen Starbranch, testified that she urged her and Rusty not to have any more children, as it would "guarantee future psychotic depression." They conceived their fifth and final child approximately seven weeks after her discharge.
[10] Yates stopped taking Haldol in March 2000 and gave birth to her daughter, Mary, nine months later.
[11]
Yates seemed to be coping well until the death of her father on March 12, 2001. She then stopped taking medication,
mutilated herself, read the
Bible feverishly, and stopped feeding Mary.
[8] She became so incapacitated that she required immediate hospitalization. On April 1, 2001, Yates came under the care of Dr. Mohammed Saeed; she was treated and released."
Features that are worth noting
Clear link between the emergence of psychotic symptoms and child-birth
Clear presence of psychotic symptoms before the killings took place
Multiple episodes of hospitalization
Multiple episodes where she was unable to take care of herself
Previous suicide attempts and self-harm
LD's history just looks way too tidy in comparison. The only disorder for which there is evidence is the depression (and possibly anxiety). There are also some signs of a personality disorder but those would not amount to an insanity defence.
IMO the amount of publicity around this case is evidence of the horrifying betrayal that has been committed here- by a sentient and normal-seeming mother. We have had infanticide cases in New Zealand before that flew under the radar- because the mothers were clearly in the throes of hallucinations and believed they had to sacrifice their baby to the devil or other things of that nature. People were much less interested in those. It sounds like I'm being flippant- but really, that was more or less the situation.
This one is darker- IMO- because there is real evidence of malice. And malice disturbs us, more than craziness.