Health chiefs have been ordered to carry out an investigation into the widespread prescription of powerful tranquillisers across Ireland.
Latest figures show almost one in six people on both sides of the border have taken either sedatives, tranquillisers or anti-depressants.
Usage is much more pronounced in Northern Ireland where more than a fifth of the population said they have taken the drugs at some stage. More than one in 10 used them last year.
It is a growing issue in the Republic, with around 5% of people south of the border last year taking anti-depressants and almost 7% taking sedatives or tranquillisers.
Despite guidelines being issued to medics in 2002, usage continues to rise.
Junior Health Minister Roisin Shortall has told the Health Service Executive to report back to her on the prescribing patterns of benzodiazepines, such as Valium or Xanax, in particular.
The medication, for stress and anxiety, can lead to addiction if used over long periods of time and their role in drug overdoses has also come under the spotlight.
Also known as benzos or BZDs, the drugs are the second most common contributor in drugs poisonings after alcohol.
"I feel that we in Ireland have a problem in relation to prescription drugs that is underestimated," said Ms Shortall.
Dr Des Corrigan, chairman of the National Advisory Committee on Drugs (NACD) said most overdoses could be prevented if people didn't use benzos mixed with other drugs, particularly with narcotics and alcohol.