There is a "significant association" between young people taking certain types of antidepressants and being convicted of violent crime such as murder and assault, a study has suggested.
A group of psychiatrists from Oxford University extracted information from Swedish national drug and crime registers and studied the correlation between violence and use of prescribed selective serotonin reuptake inhibitors (SSRIs) such as Prozac, and Seroxat.
The study, which was published on Journals PLOS, assessed 856,493 individuals who were prescibed SSRIs, which amounts to 10.8% of the Swedish population. Of these individuals, 1% had committed a violent crime.
"There was a significant association between SSRIs and violent crime convictions for individuals aged 15 to 24," the study found. "However, there were no significant associations in those aged 25 [years] or older."
SSRIs, which are used to treat depression and other mental health conditions, are not recommended for use in people under the age of 18. Previous to the study, however, there was "limited and inconclusive evidence linking SSRI use with violent behaviour".
Around 8% of people in Britain now take a medication to combat depression. The study found the 84,000 young people in Sweden taking SSRIs had committed 2,081 violent crimes over a four year period - around 890 more than expected.
"Because SSRIs are widely prescribed, it is important to clarify this latter issue," the study adds.
Writing in the journal, one of the researchers Professor Seena Fazel said: "People who were aged between 15 and 24 had a 43 per cent higher risk of committing a violent crime when medicating compared to when not medicating.
"The adolescent brain may be particularly sensitive to pharmacological interference."
The study does point out the findings cannot prove taking SSRIs actually causes an increase in violent crime among young people - because the analytical approach does not account for factors such as symptom severity or alcohol misuse, which "might affect an individual's risk of committing a violent crime".
"In addition, some people who committed a violent crime might have subsequently taken SSRIs to cope with the anxiety and stress of arrest.
The study adds: "The association between violent crimes and SSRIs among individuals younger than 25 years is worrying.
"But.. it might be inappropriate to restrict the use of SSRIs in this age group because increases in adverse outcomes associated with poorly treated depression, such as suicide, might outweigh the public health benefit accruing from decreases in violence."
Prof Gitte Moos Knudsen, Vice-President of the European College of Neuropsychopharmacology, told the Telegraph: "The study does also not show that SSRI use makes you more likely to be convicted of violent crime compared to if you had not taken SSRIs.
"The absence of dose effect, e.g., for moderate or high SSRI use supports that this is not a causal relationship."
Useful websites and helplines:
- Samaritans, open 24 hours a day, on 08457 90 90 90
- Mind, open Monday to Friday, 9am-6pm on 0300 123 3393
- Get Connected is a free advice service for people under 25. Call 0808 808 4994; email: firstname.lastname@example.org or visit the website getconnected.org.uk
- Young Minds offers information to young people about mental health and emotional wellbeing
- HopeLine runs a confidential advice helpline if you are a young person at risk of suicide or are worried about a young person at risk of suicide. Mon-Fri 10-5pmand 7pm-10pm. Weekends 2pm-5pm on 0800 068 41 41
- HeadMeds - a straight-talking website on mental health medication