He graduated in Medicine from University College Dublin (UCD) in 1985 and trained in Psychiatry at St Patricks Hospital, Dublin. He studied Addiction Psychiatry at Yale University, New Haven, Connecticut, and conducted research into new treatments for alcohol misuse.
He took charge of the addiction section of Mount Sinai School of Medicine and the Bronx Veterans Hospital, New York for a number of years, where he continued his research and founded the dual diagnosis treatment programme at St Patricks University hospital.
As well as having written numerous scientific articles on the subjects of addiction and mental health, he has also written extensively for newspapers and popular journals, and has spoken on radio and television on the same topics. He is married with three children, and lives in Dublin. Overcoming Alcohol Misuse is his first book.