Lindsay Clancy’s mental health is at the center of her murder trial. The defense concedes that Clancy committed the crime, but says she wasn’t in her right mind when it happened.

Clancy had been vocal about her struggles and was trying to get help through psychiatric hospitals and various medications.

Mark Astor has prosecuted insanity cases, and now defends people with behavioral health issues. He says this defense is an uphill climb.

"You have three dead children, and so how does a jury wrap their head around the fact that she didn't know what she was doing was wrong, and apparently before she strangled the children, she sent her husband out to go get food?" he said. "That tells you that she had intent. And if she had intent, then how could she really have been 'insane' at the time she committed the offenses?"

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But reproductive psychiatrist Dr. Nicole Cirino says women can appear to be making other rational decisions during an episode of postpartum psychosis.

“The psychosis, such as auditory or visual hallucinations, can appear quickly and can appear kind of in the context of minutes or hours," Cirino said. "And at the time of appearance, and somebody who's previously highly functioning, they can continue to function in ways that would be running tasks and executive function and planning things, even while they're having the acute hallucination or the other signs of psychosis, like paranoia or other things.”

She says women in psychosis do not understand that hurting their children is wrong. To the contrary — they think it’s the only way to save them.

Cirino says she’s found that postpartum psychosis can often be mis-dagnosed as postpartum depression or anxiety because the symptoms can be so similar.

“This is a psychiatric emergency, a biologic, a medical condition," Cirino said. "This is not just psychological, 'I feel bad.' This is a change that's happening in our brain. That's an emergency that is treatable.”

Legal experts say this case could have major implications beyond Clancy's time in the courtroom, potentially shaping how the justice system treats postpartum psychosis in future criminal cases.