COLUMBIA, S.C. AP – The South Carolina SupremeCourt upheld the murder conviction Monday of a teenager who claimed antidepressants led him to kill his grandparents and set their house on fire when he was 12 years old.

The court ruled against several arguments made by Christopher Pittman’s attorneys, including the contention that he was denied a speedy trial before he was sentenced to 30 years in prison in February 2005. He was 15 at the time of his sentencing.