At Lindsay Clancy's Massachusetts murder trial, her defence used a hospital psychiatrist's testimony to challenge prosecutors' portrayal of her as calculating and organised when she killed her three children. A psychiatrist reportedly conceded that psychosis does not necessarily prevent a person from planning and carrying out actions, an admission a legal expert described as "extremely helpful" to Clancy's defence, which centres on her mental state at the time of the deaths.

Criminal defence attorney Seth J. Zuckerman said the concession gives the defence a useful opening, but noted the case will ultimately hinge on proving Clancy's specific mental state during the killings, which remains the next hurdle for her legal team. Clancy, a former labour and delivery nurse, is accused of killing her three young children in 2023; her lawyers have argued she was suffering severe postpartum psychosis at the time.