A mother smothered her toddler daughter with a 'Minnie Mouse' pillow while she was taking a nap after becoming "obsessed" with the child's autism diagnosis, a jury has been told.

The Central Criminal Court also was told the woman described to gardaí how she held the pillow over the child's face as she struggled and screamed. Her daughter called out for her daddy and finally let out a sigh, she said.

A consultant forensic psychiatrist told the murder trial the defendant had been suffering with "recurrent depressive disorder" at the time and fulfilled the criteria for a special verdict of not guilty by reason of insanity.

In the days before the killing, the defendant had carried out internet searches on suicide and mothers killing their autistic children. She had convinced herself her child had a more severe form of autism when the diagnosis was at the milder end of the spectrum.

The woman, who cannot be named by order of the court, has gone on trial at the Central Criminal Court, having pleaded not guilty by reason of insanity to the murder of the three-year-old infant nearly two years ago.

Garda Declan Hartley agreed with prosecuting counsel Paul Murray SC that the toddler was assessed for autism in January 2018. The therapist in the centre said the child scored at the borderline spectrum of autism. Mr Murray read a statement from the woman's husband in which he said that his wife had been Googling autism and found a form of autism called Pathological Demand Avoidance (PDA).

"She immediately convinced herself that was what the child had," said the husband.

The husband said he left home that day and his child was watching cartoons. He said he never blamed his wife for what happened as he knew it had to be a psychiatric event.

The woman's sister said in a statement the accused became totally obsessed with autism.

In her garda interviews, the defendant described the weeks before the killing as a "living nightmare" and said she felt "overwhelmed" by her child's autism.

The court heard the woman smothered her child with a 'Minnie Mouse' pillow while she was taking an afternoon nap on the couch.

The woman rang 999 and told them she had tried to suffocate her child. The woman did chest compressions on her daughter but she looked grey.

The accused told gardaí she did not have a choice but to complete the act so her other child could have a happy life.

Asked whether she had something to say to her child, she replied: "I would say I'm so, so sorry."

Dr Sally Linehan, a consultant psychiatrist from the Central Mental Hospital, gave evidence that the woman first faced mental health frailties when she was in college and people had expressed concern about this. When her daughter was diagnosed with autism, she had said she felt as if it was the end of the world.

Dr Linehan said the woman suffered from a "recurrent depressive disorder" which is a mental disorder and it had an element of psychosis at the time. The woman experienced a "morbid preoccupation" with the issue of her child's diagnosis, as well as irrational thoughts that could reinforce negative and catastrophic thinking.

In cross-examination, Dr Linehan agreed with Mr Gageby that his client had misinterpreted the severity of the child's illness.

The trial continues.

Irish Independent