There needs to be more cross-over between addiction and homeless services, it's claimed.
A major conference organised by the Irish Medical Organisation and BMA Northern Ireland will take place today to discuss the link between mental health and addiction.
Topics will include the impact of the recession on mental health, how to recognise behavioural addictions and its wider impact.
Fr Peter McVerry, one of the speakers at today's event, will give a presentation on the relationship between addiction and homelessness.
He said there is no cross-over between addiction and homeless services, and labelled it a "disaster".
"Why would a homeless person bother coming off drugs? If they come off drugs, go through an intensive treatment programme, and then they come looking for accommodation from the homeless services, they will be placed in a dormitory full of drug users.
"In 48 hours, they'll be back on drugs again. It's a total and absolute disaster."