Mother guilty of murdering 'bipolar' child

A US woman has been convicted of second-degree murder over the 2006 death of her four-year-old daughter from an overdose of powerful psychotropic drugs.

The case rekindled a debate about the rising diagnosis of very young children with serious psychiatric conditions, and their treatment with potent medications.

A judge sentenced Carolyn Riley, 35, to life in prison with eligibility for parole in 15 years after a jury convicted her in Brockton, Massachusetts. She is expected to appeal.

Her husband Michael Riley, 37, will be put on trial separately starting in early March on murder charges over his daughter's death.

Prosecutors said Riley and her husband fabricated severe behavioral problems in their daughter to obtain drugs and to qualify for federal disability benefits, then overmedicated the girl to keep her quiet.

The defence attributed the death to rapid-onset pneumonia and said the parents were following a psychiatrist's direction in the cocktail of drugs given to the girl.

The jury deliberated for almost four days before returning the guilty verdict after a three-week trial.

Rebecca Riley was diagnosed with bipolar disorder, a condition characterised by severe mood swings, and attention deficit disorder before her third birthday, and placed on the medications at that time.

A state medical examiner concluded that Rebecca died of a combination of Clonidine, a blood pressure medication sometimes given to attention deficit hyperactivity disorder patients; Depakote, an anti-seizure and mood-stabilising drug used to treat bipolar disorder; and two over-the-counter drugs including a cold medicine.