One of Ireland's largest drug treatment centres has reported a rise in addiction to a cocktail of alcohol, cocaine and benzodiazepine among the clients using its service last year.

The Coolmine Therapeutic Community also said there was a sharp decline in the use of heroin in the Dublin area in 2012.

However, it says opiates remain the primary drug in the rest of Ireland.

In its annual report, the Coolmine Therapeutic Community notes new admissions increased by 37% last year compared to 2011.

Over 1,000 clients were helped during 2012.

Around 42% of them were treated for addiction to a cocktail of benzodiazepine, cocaine and alcohol, compared with 33% being treated for addiction to a similar cocktail the previous year.

The centre said the rise in addiction to this mixture of drugs is a major concern, and believes it is due to the ease of access to alcohol and benzodiazepine, which is used to treat mental health disorders.

Coolmine has called on the pharmaceutical and alcohol industries to begin funding services that prevent and treat addiction in Ireland.

The centre also reported an increase in the average age of its users to 30.