42% of Irish people meet the requirements for at least one mental health disorder.
That's according to a joint study from Trinity, Maynooth University and the National College of Ireland, which also shows 11% have attempted suicide.
The most common disorders found were insomnia, anxiety, alcohol abuse and depression.
"Studies by the World Health Organization indicate that this figure [42% of people meeting requirement for at least one mental health disorder] is similar to what has been found in the United States and New Zealand," said Dr Phillip Hyland who is an associate professor in the Department of Psychology at Maynooth University and led this study.
He continued to say, "mental health disorders are extremely common, and it is important that the public and the Irish Government understand the level of need that exists.
Those most likely to experience symptoms were younger, doing a shift-work job and experiencing a traumatic life event.
If you need to talk to someone there is help available. You can call:
Or you can contact the HSE's YourMentalHealth information line on 188 111 888.