Up to 500,000 people take anxiety pills in Ireland.
Thereports today that almost 2.3 million prescriptions were written for anxiety and depression drugs in 2012.
330,000 of those were public patients, at a cost of €40m to the state.
The figures are based on analysis of the top five most frequently prescribed anti-anxiety drugs under the General Medical Services scheme.
10% of people in Limerick have been prescribed the pills – the highest in Ireland.
South Dublin had the lowest consumption, at 4% of the population.
Dr Ide Delargy, Director of the Substance Misuse Programme at the Irish College of General Practitioners, said we need to be careful about jumping to conclusions about over-prescribing.
"We would have to be cautious about how we interpret these figures," she said. "It's a complex areas and there are a number of issues at play."
"Doctors, by and large are very careful about how they prescribe, and would deal with each case on an individual basis.
She said assuming there is over-prescribing on a wholesale basis "would not be a sensible approach to take."