Rebecca Riley seemed a normal, playful young child, if at times a little boisterous. Then, aged 2, she was diagnosed with attention deficit hyperactivity disorder, and at 3 as having a bipolar personality. By the age of 4, Rebecca was dead, killed by an overdose of the drug clonidine, which was being used to treat her condition. She was also taking the anti-convulsant Depakote (valproate) and the anti-psychotic Seroquel (quetiapine fumarate) to stabilise her mood.

Rebecca died next to her parents’ bed in Hull, Massachusetts, on 13 December last year. This Wednesday a pre-trial hearing began that will be followed …