People with serious drug and alcohol abuse problems are linked to about a quarter of all violent crimes, many of which could be avoided with better treatment, researchers in Sweden reported on Friday.

They found that 16 percent of crimes, such as murder, robbery, assault and rape, in Sweden between 1988-2000 were committed by people who had been discharged from hospital for alcohol abuse and 10 percent of crimes were associated with drug abusers.

“It is likely you will find the same sort of figures in Western Europe and North America,” Seena Fazel, of the University of Oxford, said in an interview.

Fazel and Martin Grann, of the Karolinska Institute in Stockholm, studied the country’s national crime register and compared it with hospital discharges of people diagnosed with alcohol and drug misuse and psychoses.

Few countries, apart from Scandinavian nations, have such detailed population-based registers that are needed to conduct such a study.

In addition to alcohol, abuse of amphetamines and opiates, such as heroin, and the use of multiple drugs were linked to the most violent crimes.

“There needs to be more integration between the criminal justice system and mental health services because of this close association between crime and people who leave hospital with drug and alcohol problems,” said Fazel, who reported his findings in the British Medical Journal.

“Using resources to treat people with these problems could be cost effective in terms of crime reduction,” he added.

In Britain alone, drug-related crimes cost the criminal justice system about 1 billion pounds ($1.8 billion) annually.

Fazel suggested that opportunities for treatment should be considered if a person with a history of alcohol or drug abuse has been convicted of committing a violent crime.

“Probation officers and mental health professionals should continue to work more closely,” he added.