Prescription antidepressants, tranquilizers and painkillers all increase risk of murder

(NaturalNews) People taking antidepressants, tranquilizers and painkillers are all significantly more likely to kill another human being than similar people who are not taking those drugs, according to a study conducted by researchers from the Karolinsksa Institutet in Stockholm, Sweden, and published in the journal World Psychiatry on June 1.

Following high-profile school shootings in the United States and Finland, commentators have wondered whether antidepressants being taken by the shooters might have played a role in their actions.

"It has been repeatedly claimed that it was the antidepressants used by the persons who committed these massacres that triggered their violent behavior," researcher Jari Tiihonen said. "It is possible that the massive publicity around the subject has already affected drug prescription practices."

Shockingly, however, the new study found that painkillers were actually the drugs most strongly linked to homicide, with non-prescription painkillers showing the strongest link.

People on painkillers three times more likely to kill

For the new study, the researchers collected data from the Finnish Homicide Database of the Institute of Criminology and Legal Policy on 959 people convicted of homicide. They then consulted the Finnish Prescription Register of the Social Insurance Institution of Finland to see whether the murderers had used any prescription drugs during a seven-year period (2003-2011) prior to committing homicide. The researchers also reviewed police reports to see if the convicted killers had been reported to be intoxicated at the time of the killings.

Each convicted killer was matched with 10 other people of the same age and gender who lived in the same town but had not been convicted of homicide, and these 9,590 people were also looked up in the Prescription Register.

The researchers looked at prescription drugs including antidepressants, antipsychotics, benzodiazepines (tranquilizers, used for anxiety and insomnia), epilepsy drugs, addiction control drugs and painkillers.

Among psychiatric drugs, there was no connection between antipsychotic use and the chance of killing someone. Antidepressant use, in contrast, raised the risk of becoming a killer by 31 percent. Tranquilizer use increased it by 45 percent.

Surprisingly, these effects were dwarfed by the effects of drugs not typically considered psychiatric in nature: painkillers. People who took opioid (narcotic) painkillers were 92 percent more likely to kill someone, while those taking prescription anti-inflammatory drugs were a shocking 206 percent – that is, three times – more likely to kill someone.

The effects were even more striking among those under the age of 26. In this age group, the use of benzodiazepine tranquilizers increased the risk of committing a homicide by 95 percent, while the use of narcotic painkillers increased the risk by 223 percent.

Drugs weaken impulse control, emotional processing

Of course, the study proves only that there is a correlation between the use of certain drugs and homicide, not that the drugs actually cause their users to kill people. But the findings are certainly cause for concern, especially since the drugs in question are all known (indeed, designed) to disrupt the function of the brain.

Although antidepressants were, as suspected, associated with a higher risk of committing homicide, Tiihonen emphasized the greater risks found with other drug classes.

"If anything, we should be concerned about prescriptions of high-dose benzodiazepines and opioid painkillers for people with substance abuse," he said.

Tiihonen noted that many of the killers studied had been long-term users of high-dose tranquilizers before committing their crimes.

"Benzodiazepines can weaken impulse control, and earlier research has found that painkillers affect emotional processing," he said. "Caution in prescribing benzodiazepines and strong painkillers to people with a history of substance abuse is advisable."

Sources:

http://www.livescience.com

http://www.medicalnewstoday.com