A leading psychiatrist has claimed that the murder-suicide in Bray two weeks ago would not have happened if Shane Clancy had not been prescribed antidepressant medication.

Dr Michael Corry, who is an outspoken critic of anti-depressants, said: "If he was not on medication, he would not have done what he did. I would stake my career on that. His behaviour was out of character. He went from homicidal to suicidal. It's a Jekyll and Hyde situation,"

Clancy (22) started taking medication a week before he murdered Sebastian Creane and stabbed his former girlfriend Jennifer Hannigan before committing suicide.

Clancy had told friends that he did not like the way the drugs made him feel and gardaí believe that he may have been misusing the medication by taking more than the recommended dosage.

Dr Corry, who has a private practice in Dublin, said that the side affects of anti-depressants can be severe when people initially take them.

"In the first three to seven days [on anti-depressants], people can feel totally out of character and worse than before. Side effects can be patients wanting to self-harm, commit suicide and harm others," he added.

"Anti-depressants inhibit oxytocin, which is basically the self-love hormone. It results in an emotional numbing. People can be feeling no pain but not alive either."

Professor Patricia Casey, professor of psychiatry at the Mater Hospital and University College Dublin, said that some people can experience "unpleasant side effects" from anti-depressants, such as increased agitation and anxiety. However, she added she did not think this would occur in the first two weeks as it is accepted in the medical community that anti-depressants do not work for up to 14 days.

A Sunday Tribune investigation has found that anti-depressant prescriptions can easily be obtained under false pretences.

This newspaper visited five GPs in Dublin and Bray last week feigning depression and obtained prescriptions from four doctors for antidepressants.

Prof Casey and Dr Corry both said they would not have prescribed anti-depressants to the Sunday Tribune given the symptoms described.

"I think we prescribe anti-depressants far too easily in this country," said Prof Casey