A nation-wide Swedish population study suggests that almost one quarter (23 percent) of all violent crimes are committed by people with serous substance abuse problems involving alcohol or other drugs, according to an article in the May 22nd issue of the British Medical Journal.

Although previous studies have suggested a correlation between substance abuse and violent crime, the current study is the first to date to use national data to estimate the social impact of substance abuse on crime. The authors hypothesized that if the correlation were substantial at the population level, public health officials would be able to justify design of interventions that would help the substance abuser at the individual level and decrease the social costs of drug-related crime.

The researchers used Swedish national psychiatric and crime registries from 1998 to 2000 to calculate the impact of substance misuse on violent crime in that nation.

During that three-year period, 16 percent of all violent crimes in Sweden were committed by people who had been discharged from hospital with a diagnosis of alcohol misuse, and more than 10 percent of all violent crimes were committed by patients diagnosed with other drug abuse. The overall proportion of violent crimes in the whole population that can be attributed to patients with substance misuse was 23 percent.

The authors recommend extension of mental health and substance misuse services to the criminal justice system in order to identify and serve people who need psychiatric evaluation and treatment.