A new study has raised serious concerns about how some people prescribed antidepressants are affected by the drugs.
Psychologists in the U.S. say it appears that people taking prescription antidepressants are worse drivers than people not on such drugs.
They say depressed people on antidepressants have far more trouble concentrating and reacting behind the wheel.
The team from the University of North Dakota recruited 60 people to participate in a driving simulation exercise where the participants had to make a series of common driving decisions, such as reacting to brake lights, stop signs or traffic signals, while being distracted by speed limit signs, pylons, animals, other cars, helicopters or bicyclists.
The exercise tested the skills needed for steering, concentration and scanning. 31 of the participants were taking at least one type of antidepressant while 29 in the control group were taking no medications apart from, in some cases, oral contraceptives.
The group on the antidepressants were then subdivided into those who scored higher and lower on a test of depression.
It was found that the group taking antidepressants who reported a high number of symptoms of depression performed significantly worse than the control group on several of the driving performance tasks.
However participants who were taking antidepressants and scored in the normal range on a test to measure depression performed no differently than the non-medicated individuals.
Researchers Dr. Holly Dannewitz and Dr. Tom Petros say individuals taking antidepressants should be aware of the possible cognitive effects as they may affect performance in social, academic and work settings, as well as driving abilities.
They also say that mood appears to be correlated with cognitive performance, more so than medication use.
Experts say the research is important in light of the rapid increase in the number of people taking antidepressants.
In the U.S. the use of antidepressant drugs such as Prozac, Paxil or Zoloft, has almost tripled in a decade, according to reports and it is thought that 1 in every 10 women takes an antidepressant drug.
The research was presented last weekend at the Annual Convention of the American Psychological Association in Boston.