Changes in patterns of excessive alcohol consumption in 25 years of high security hospital admissions from England...

It is now generally acknowledged that alcohol abuse increases the risk of violence among people with major mental disorder. Studies in the 1980s and earlier, however, tended to report an inverse relationship between their alcohol use and violence.

A study was undertaken to test a hypothesis that among people with major mental disorder considered to pose a serious risk to others the likelihood of excessive alcohol consumption in a period leading up to a violent or dangerous act has increased over time.

Analysis was made of annual high security hospital admission cohort case register data of 1 January 1975 to 31 December 1999; alcohol use data were taken from interview and records, and problem drinking defined as consumption of alcohol in excess of 21 units per week during the 12 months prior to the index offence or act.

There was a linear increase in the proportion of patients in five-year admission cohorts who had engaged in excessive alcohol consumption during the year prior to their index offence or act. The increase was steeper among women than men, but cut across all diagnosis and offending groups. It was strongly associated with increasing tendency to abuse illicit drugs.

The greater proportion of patients affected by excessive alcohol consumption occurred in spite of a reduction over the same period in admission of people in the diagnostic groups most likely to be implicated in substance misuse (personality disorder). This increased trend may simply reflect similar trends in the general population, but may also be associated with a lack of services or current consensus on appropriate treatment for patients whose mental illness is complicated by excessive alcohol use. Regardless, the trend suggests a growing need for 'dual diagnosis' services within and outside high security hospital.