Intrusive thoughts and hoarding are the most common symptoms experienced by Irish people with obsessive compulsive disorder.
The condition, which was the subject of a recent RTE documentary called OCD and Me, affects between two and three percent of the population.
People with OCD experience repetitive and upsetting thoughts and behaviours.
St Patrick's Mental Health Services in Dublin recently asked the public to complete a questionnaire, where participants were asked what symptoms they experience with OCD.
People reported symptoms of compulsive checking and fears around contamination in the survey along with the top answers of intrusive thoughts and hoarding.
"Many young people have mild obsessions and compulsions, for example, having to organise their toys in a special way. This is normal and may be the result of worry due to stress or change," said St Patrick's CEO Patrick Gilligan.
"OCD can start at any time from pre-school age to adulthood, with typical age of onset being during adolescence or early childhood. We need to be more vigilant about our young people's mental health because the earlier we identify the difficulty, the easier it is to address it," he said.
OCD Ireland run support groups from St Patrick's University Hospital and Trinity counselling service.