The study targeted 20-year-olds.
Poorer wellbeing, higher levels of aggression and negative coping strategies have been found among pornography users.
A study from the ESRI also found those who watch porn report more depressive symptoms.
It interviewed a number of 20 year olds, who were offered the chance to answer the most sensitive questions in private.
Psychotherapist in Westmeath, Rory Hafford, says the sex education children are being exposed to is online porn:
The study also found young people who use pornography are less likely to use condoms.
Men who use porn also generally have poorer wellbeing and are less satisfied with their lives.
One of the report's authors, Emer Smyth, says young men often copy what they see: