She was on a lot of drugs. She was prescribed 13 different psychiatric medicines over a one year period, according to AI. She had 4 different drugs in her system when she murdered the kids but she didn't take a lot of the pills she was prescribed, probably because they didn't help her.

She had severe postpartum depression/psychosis and should never have been allowed to care for her children alone. My sister-in-law had postpartum depression and she hated her newborn son. My mother-in-law took care of the baby for awhile until she could be trusted to care for him. She eventually grew out of the depression. I don't know if she took drugs to do it but her mother and husband made sure she didn't harm the baby.

The drugs she took didn't help, but Lindsay Clancy hated her kids at that time without any drugs. A woman with postpartum depression/psychosis has a warped view of motherhood and they're capable of anything.