People have about the same risk of having suicidal thoughts or attempting suicide when starting out on antidepressants no matter what type of pill they're prescribed, new research shows.
"There is no meaningful difference between these agents," said Dr Sebastian Schneeweiss of Brigham and Women's Hospital and Harvard Medical School in Boston, one of the study's authors.
This means that psychiatrists prescribing antidepressants can base their choice on what works best for the patient, rather than what's safest, he explained. But the findings don't mean that the drugs are risk-free, Schneeweiss added.
"You always have to worry about the safety of these medications, the increased (suicide risk) is still there," he said.
The US Food and Drug Administration issued a warning in 2004 that children and adolescents taking antidepressants might have an increased risk of suicidal thoughts and behaviours.
In 2006, it extended the warning to include young adults up to age 25.
All antidepressants carry warning
All antidepressant labels must now carry a "black box" warning stating that they can increase a person's likelihood of suicidal thoughts and behaviours.
But it has been difficult to pin down whether a certain antidepressant drug or class of medications might be more dangerous -- or safer -- than others, Schneeweiss noted.
To investigate, he and his colleagues looked at data on nearly 300 000 adults in British Columbia, Canada, who had been prescribed antidepressants between 1997 and 2005.
They evaluated whether specific medications would increase the risk that a person would attempt or complete suicide during their first year of taking that drug.Among the 287,543 men and women in the study, there were 751 suicide attempts and 104 suicides.
What the study found
Schneeweiss and his team found no difference in risk between different classes of medications, such as selective serotonin reuptake inhibitors (SSRIs for short, which include Prozac, Zoloft and other widely used medications) or older antidepressants called tricyclic antidepressants.
Risks also were similar for individual SSRIs.
In April, Schneeweiss and his colleagues published a similar study in the journal Paediatrics of 20,000 10- to 18-year-olds that found no difference in suicide risk among antidepressants.
It's still unclear why antidepressants could increase suicide risk, Schneeweiss noted in an interview. "You cannot really tease that apart in non-randomised studies," he added. But for now, he and his colleagues conclude, "clinicians should be vigilant in monitoring after initiating therapy with any antidepressant agent." - (Reutetrs Health, May 2010)