Is Sudden Infant Death Syndrome caused by a serotonin imbalance?

There can be few events more devastating for a parent than cot death - the sudden and unexpected death of a baby. Cot death is more formally known as Sudden Infant Death Syndrome (SIDS) and it is an apt title, for affected babies often seem outwardly healthy and show no signs of suffering. Studies have suggested that things like passive smoke and breastfeeding can affect the risk of SIDS but the underlying biology behind the syndrome is a mystery, as is the cause of death in most cases.