No link between suicidal behaviour and drugs for ADHD

by Bruce Sylvester – Researchers report that drug therapy for ADHD does not increase the risk of suicide attempts or suicide. The findings were published on June 18, 2014  in the British Medical Journal/BMJ.

“Our work in several ways shows that most likely there is no link between treatment with ADHD drugs and an increased risk of suicide attempts or suicide. The results rather indicate that ADHD drugs may have a protective effect,” said lead investigator Henrik Larsson, PhD, of the Department of Medical Epidemiology and Biostatistics, Karolinska Institute in Stockholm.

As background, the authors noted that prior research suggested that ADHD drug treatment  increased suicidal thoughts. But, they emphasized, the studies were small scale and the methodology limited, rendering the results uncertain.

The researchers in the newly reported study used national patient registers to identify all patients in Sweden diagnosed with ADHD between 1960 and 1996, totaling 37,936.

They evaluated data on these subjects for 2006-2009, in terms of drug treatment and events designating suicide attempts and suicide.

They compared the rate of suicidal behaviors while subjects received ADHD medication to the rate for the same patients while not receiving medication. In this way the investigators determined that there was no evidence to support the hypothesis that ADHD drug therapy increases the risk of suicide attempts/suicide. Since all subjects were compared to themselves, this allowed the researchers to determine the differences between those receiving drugs and those who did not.

“Many epidemiological studies on the risks related to drugs fail to adjust for the differences between individuals who take the drugs and those who do not. This is a critical limitation given that the individuals on medication are usually more severely ill than the others,” added Larsson.