The use of some psychiatric drugs, especially benzodiazepines, which are prescribed for their tranquilizing effects, may increase the risk of committing a homicide, according to an analysis of homicide and prescription drug databases in Finland.
The startling finding was made by Jari Tiihonen, MD, PhD, of the Karolinska Institute in Stockholm, Sweden, and colleagues after they analyzed prescription drug use of 959 people who were convicted of homicide.
The team examined use of prescription drugs before the crime was committed among all people convicted of homicide in Finland between 2003 and 2011 utilizing two databases: the Finnish Homicide Database of the Institute of Criminology and Legal Policy, and the Finnish Prescription Register of the Social Insurance Institution of Finland, Kela.
Interestingly, after confounding factors were accounted for, antipsychotics were not associated with an elevated risk of committing a homicide, the researchers reported in the journal World Psychiatry. Use of antidepressants was associated with a 31% higher risk, and for benzodiazepines, the figure was 45%.
But the highest risk in committing a homicide came from using opioid-based painkillers — a 82% increased risk — and from non-inflammatory pain medication — a 206% increased risk.
“Benzodiazepines can weaken impulse control, and earlier research has found that painkillers affect emotional processing,” Tiihonen said in a statement. “Caution in prescribing benzodiazepines and strong painkillers to people with a history of substance abuse is advisable.”
However, the authors cautioned that their study only found an association and not a causal relationship between these medications and risk of committing a homicide,
A study analyzing the Finnish homicide and prescription drug databases discovered that the use of certain drugs that affect the central nervous system are associated with an increased risk of committing a homicide.
The greatest risk was associated with the use of painkillers and tranquillizing benzodiazepines, while anti-depressants were linked only to a slightly elevated risk. The study is the first one of its kind in the world.
Professor Jari Tiihonen’s research group analyzed the use of prescription drugs of 959 persons convicted of a homicide.