ADHD drug does not trigger suicidal thoughts
Swedish research shows that there is no link between the ADHD medication atomoxetine and suicide.
The number of people in Norway who receive medication for ADHD has tripled in the last ten years. The medication can suppress symptoms and improve the quality of life for those who are being treated with the drug.
One of the ADHD drugs currently on the market is called atomoxetine. It works on a part of the central nervous system.
However, previous studies have suggested that it may also have a dangerous side effect: an increase in the frequency of suicidal thoughts.
Products with this component have included warnings to this effect for a number of years, and the Norwegian Medicines Handbook contains a reference to “indications of an increased incidence of suicidal behaviour”.
More than 37,000 patients followed
This reputation is undeserved, according to new research from the Karolinska Institute in Stockholm. The researchers followed all Swedes with an ADHD diagnosis – 37,936 people – from 2006 to 2009.
The aim was to identify the relationship between ADHD drugs and suicide-related events.
“Our research shows clearly that ADHD medications should not be linked to increased risk of suicide or suicide attempts. In fact, it is more likely that they have the opposite effect,” says project leader Henrik Larsson, a researcher at the Department of Medical Epidemiology and Biostatistics.
The research that originally led to the spurious link was based on quite small studies and used methodology that was more uncertain,” according to a press release from the Karolinska Institute.
“In many epidemiological studies on the risk of drugs, it is not possible to control differences between those who take medication and those who do not,” says Larsson.
“Those who are treated are usually more severely ill than those who are not. This can lead to an erroneous link to the drug rather than to background factors,” he explains.
For example, patients may already have a tendency to think suicidal thoughts before starting the medication.
To avoid this potential source of error, the new study was based on analysis at the individual level (which is called “within-patients methodology”) rather than at the group level. The individual patients were compared with themselves at other points in time. Performing this type of analysis makes it easier to weed out background factors that may otherwise affect results.
The study followed the same ADHD patients during periods with and without drug treatment – and no significant differences were found.
“We found no evidence of an increased incidence of suicide-related events in connection with the use of atomoxetine,” concludes the research report.
The researchers end their paper with a strong recommendation that the within-patients methodology be used in future drug studies to avoid false alarms.
Translated by: Lars Nygaard
- Chen, Sjölander, Runeson, D’Onofrio, Lichtenstein and Larsson: Drug treatment for attention-deficit/hyperactivity disorder and suicidal behaviour: register based study, British Medical Journal, June 18 2014, doi: 10.1136/bmj.g3769