Research presented to an Oireachtas committee preparing a report on suicide shows 93 per cent of men under 30 who took their own lives had alcohol in their system, according to Fine Gael deputy Dan Neville.
Mr Neville said yesterday that a study in counties Louth, Meath and Cavan had produced this startling figure.
He said GPs report that 20 per cent of patients who died by suicide had a history of alcohol abuse, while psychiatrists report 27 per cent of patients who died by suicide had a history of alcohol abuse.
He said the Government's failure to implement the report of the national task force on alcohol was having a serious negative impact on suicide prevention efforts.
"Aggressive marketing, political lobbying by the drinks industry and the increase in disposable income has increased access to alcohol with its well-described depressant effect on mood and the increase in distorted judgment and impulsivity in its wake.
"Where suicide is concerned, alcohol is as lethal a drug as any other," said Mr Neville, who is his party's deputy health spokesman. "While suicide is a complex issue, the role which alcohol plays is undoubted."
He said that during the 1990s Ireland had experienced a 41 per cent rise in alcohol consumption and that suicide rates increased by 44 per cent, showing an almost 100 per cent correlation.
"More recently, a study into unnatural deaths in 2001 and 2002 in counties Louth, Meath and Cavan found that 93 per cent of young men aged less than 30 years who had ended their lives had alcohol in their system."
Some 58 per cent of these had a blood-alcohol level of greater than 160 mg/dl, twice the legal alcohol limit for driving. Some 25 per cent had a blood-alcohol level of greater than 240 mg/dl, three times that limit.
"By comparison, no man over 30 years lost to suicide had the same level of alcohol consumed, which indicates that this is a key issue for younger people."
Mr Neville pointed to a six-year study carried out by the Co Louth coroner, published in January 2006, which showed that 48 per cent of the 47 people of all ages who died by suicide in his area of inquiry had consumed alcohol before ending their lives.
"The effect of alcohol consumption on the adolescent and young adult brain causes an even greater depletion in important mood-stabilising neurotransmitters than occurs in a mature adult brain.
"A high level of alcohol consumption as might occur in a drinking binge can induce a significantly depressed mood state over the subsequent eight to 12-hour period."