Trial hears drink and drugs rather than mental disorder had role to play in Tallaght murder

A murder trial has heard psychiatric evidence drink and drugs rather than a mental disorder may explain Dublin woman Tanya Doyle's state of mind when she stabbed her husband over 60 times.

The 40 year old admits killing engineer Paul Byrne at their home in Pairc Gleann Trasna, Aylesbury in Tallaght, Dublin on September 4 2009, but denies his murder.