The study found that over half of 14 to 18-year-olds had self-harmed, 70% had suicidal thoughts and one in three had attempted suicide.
HSE national office for suicide prevention, reveals that LGBT people still experience bullying at school, fear of rejection and discrimination, violence and negative attitudes.
It found the most common age people discover their LGBT identity is 12 but it is another four years before they tell the first person of their sexual identity.
One in four had not told their parents that they are LGBT.
Meanwhile 3% had not come out to anybody with fear of rejection and discrimination one of the main reasons they continued to conceal their identity.
The fear of rejection was strong where there was an awareness of negative attitudes within their family or among friends.