SHANE Clancy had "toxic-to-fatal" levels of anti-depressants in his system on the night he went on a tragic stabbing spree.
Professor David Healy of Cardiff University expressed concern to Wicklow East Coroner's Court about the drug Cipramil taken by Clancy, saying that it was known to cause "suicidal and homicidal thoughts" among "a minority" of people.
He believed Clancy had suffered an adverse reaction to the drug and should not have been prescribed it.
Prof Healy stressed that many people can use the drug safely, but told the inquest that he had concerns over the safety warnings given to the drug in Ireland.
Assistant State Pathologist Dr Declan Gilsenan said the post-mortem examination on Clancy's body revealed 19 superficial abrasion lesions and six stab wounds to his chest and upper abdomen.
No alcohol or other drugs were found but levels of a prescribed anti-depressant, an SSRI drug, were present "at a somewhat excessive level". He agreed with Coroner Cathal Louth that the drug was present in "toxic to fatal" levels.
He said the Committee on Safety in Medicine in England had advised that SSRIs should not be used by anyone under 18, as "trials suggest harmful outcomes".
One theory on the drug suggests a danger period at the start of treatment because before the drug actually lifts the depression, it alters a person's ability to make decisions, said Dr Gilsenan.
The cause of death was shock and haemorrhage due to a stab wound to the heart.
In a highly emotional and moving deposition, Shane Clancy's mother, Leonie Fennell, told how her six-foot-tall son, a student of Irish and Theology at Trinity College, had slipped into depression last summer following the break-up of a three-year long relationship with his girlfriend, Jennifer Hannigan and was "miserable with the weight of a broken heart."
His mother persuaded him to go to the doctor on July 18 last year. The doctor told him to go away, to exercise and to eat properly but he showed no improvement and on July 22, his mother brought him back and the doctor prescribed a month's supply of the anti-depressant Cipramil.
On August 5, he took an overdose of the anti-depressant and two days later, Ms Fennell brought her son to a locum doctor and was "surprised" when he received another prescription for the same drug.
Ms Fennell broke down as she told the inquest how her world had become "a living nightmare".
After the inquest, Professor of Clinical Psychiatry Patricia Casey read a statement expressing the College of Psychiatry of Ireland's disappointment at the Coroner's decision not to allow it to give evidence.
She said there were aspects of the evidence with which the college took issue.
Speaking after the inquest, James MacGuill, a lawyer for the Clancys, said the family was happy with the open verdict and believed it marked the beginning of a new and hopefully happier chapter for their family, the Creane family and for Jennifer Hannigan.
They also hope the case would heighten public awareness about the issues surrounding anti-depressant medication and lead to the introduction of treatment protocols "that match" best international practice.
However in a statement last night, Lundbeck, the drug manufacturers disputed the evidence given and claims made about Cipramil (citalopram) in the inquest, and said the drug has been used by 130 million patients worldwide.
"Extensive scientific studies have shown that there is no evidence linking citalopram to violent behaviour," the statement read.
It said there are trials which show that citalopram "has the potential to reduce, rather than provoke, irritability, aggression and violent behaviour", and said data showed no increased risk of suicide.
- Nicola Anderson