Antipsychotic drugs can help reduce the number of violent crimes, a new study suggests.
Research has found people with a psychiatric illness that do not take medication are nearly twice as likely to commit a violent crime than those who take clozapine, risperidone or other drugs.
Mood-stabilising drugs such as lithium or carbamazepine can also help lower the violent crime rate, but only in men with a bipolar disorder, and not by as much as antipsychotic drugs.
The psychiatric diagnoses of 40,937 men and 41,710 women in Sweden who were given mood-stabilising and antipsychotic drugs between 2006 and 2009 were analysed for the study, which was published in The Lancet.
A team of British and Swedish researchers, led by Dr Seena Fazel of Oxford University, found that 6.5% of the men and 1.4% of the women were found guilty of a violent crime in those three years.
Those patients who received antipsychotics committed 45% fewer violent crimes than during periods when they were not on medication, while the figure was 24% lower for those on mood stabilisers.
Combining both types of drugs had no further effect on the number of violent crimes carried out, the researchers found.
The team also discovered that, although the drugs are generally prescribed to people with schizophrenia or bipolar disorder, many study participants were taking them for other conditions such as depression or substance misuse.
Up to one in 50 people in the UK (2%) are thought to suffer from schizophrenia, bipolar disorder or related disorders.
Dr Fazel said it was unknown until now whether antipsychotic and mood-stabilising drugs have any impact on the level of violent crimes committed.
He added that his team’s research suggested the risk of violence could be substantially reduced by antipsychotic drugs, and that violence could even be preventable in patients with psychiatric disorders.