A FIFTH of prisoners in Mountjoy jail are using heroin every day, or several times a week, according to a new study.
More than 40 per cent of prisoners surveyed admitted to a researcher in the Dublin jail last year that they were using heroin during their current sentences.
The study, based on a representative sample of more than 100 prisoners, indicates a significant increase in the level of drug use in the jail.
It found that 86 per cent used cannabis, and indicated that some, who found cannabis difficult to obtain in the prison because of a security crackdown, had turned to heroin instead.
The findings indicate a doubling in the level of serious drug use in the all-male jail since 1986, when a similar survey was conducted.
The study was carried out by Dr Paul O'Mahoney for the Department of Justice, which published it yesterday. Dr O'Mahoney identifies the growth in drug use in the jail as "by far the most far-reaching and important change" since his 1986 study.
The governor of the prison, Mr John Lonergan, said it would be disappointing if attention focused on the drug abuse levels found in the survey.
He said the number of convicted drug addicts being committed to the jail had doubled since 1986, and that "if you're sending that many drug addicts to a prison, you're bound to have a drug problem in the prison".
He said the true message of the study was in its finding that most prisoners came from a small group of disadvantaged areas in Dublin and from similar family backgrounds.
The Mountjoy prisoner is typically aged 28 and often from one of just six disadvantaged areas of Dublin with a high proportion of corporation housing and social deprivation. There were six or more children in his family, and he has a good chance of having had a father or brother in jail. He left school before the age of 16. He has 14 previous convictions and has been sent to jail 10 times.
The study also found Mountjoy prisoners tended to be serving longer sentences compared to the 1986 study, reflecting both more severe sentencing by judges, and the growth in early release of shorter-sentence prisoners.
In a comparison with prisoner surveys in England and Wales, Dr O'Mahoney found that Irish judges were far more likely to send a prisoner to jail than hand down a community-service sentence, even though they were often dealing with less serious offences than the judges in England and Wales.