Antidepressant Use Tied to Poorer Driving (HealthDay)

SUNDAY, Aug. 17 (HealthDay News) -- Taking prescriptionantidepressants while still highly depressed could impair driving ability,a new study suggests.

"We already know that depression causes concentration problems," saidstudy author Holly J. Dannewitz. "And now it appears that people takingantidepressants who also have relatively higher depression scores faresignificantly worse when attempting to perform a computerized simulationof driving."

Dannewitz conducted her research while a graduate student at theUniversity of North Dakota in Grand Forks, where she is currently apsychology resident in a private practice.

She and her colleagues were scheduled to present their findings Sundaythe American Psychological Association annual meeting, in Boston.

To gauge the possible impact antidepressants might have on drivingperformance, the research team asked 60 people to "drive" a computerizedversion of a car in a program that mimicked real-world conditions.

Approximately half of the participants were taking at least one type ofantidepressant, while the other half was taking no medication (other thanoral contraceptives in certain instances). Those on antidepressants werescreened for current levels of depression and were subsequentlycategorized as experiencing either low or high depression at the time ofthe driving test.

Participants had to perform common driving tasks such as braking,steering, and scanning sightlines in response to an unfolding video of cartraffic, stop signs, speed limit signs, traffic lights, deer crossings,bicyclists, and even the appearance of helicopters.

People taking antidepressants who were highly depressed registeredmarkedly worse scores on some driving skills than those not takingantidepressants, the team found. This appeared tied to poorerconcentration and a weakened ability to react well to situations thatdivided their attention and relied on memory skills.

These deficits weren't found among those who were takingantidepressants but had low depression scores. In fact, that group wasfound to execute their driving tasks with a precision equal to that ofthose not on medication.

Dannewitz said that her future work would involve patients who arediagnosed with clinical depression but not on antidepressants. In thisway, her team can determine whether it's the depression, or medicationsused to treat it, that are at the root of the concentration problems.

"More research needs to be done, of course," she said. "And I wouldn'twant to instill fear in drivers. But I think that perhaps individuals whoare taking these medications should just be aware of the fact that theymay cause concentration problems and impair reaction time."

Dannewitz also stressed that, "this issue is not just a question fordrivers, because the cognitive skills needed for driving are also neededfor a lot of other skills."

Dr. Bernard Carroll, scientific director of the Pacific BehavioralResearch Foundation based in Carmel, California, agreed that it's tooearly to draw specific conclusions from the study. But he said thefindings weren't surprising.

"There is already a very deep literature about subtle impairments ofhigher cognitive function associated with clinical depression itself,apart from medications," he noted. "I would add that, in any case,medication package inserts routinely warn patients about a whole host ofissues when starting a course of psychotropic drugs, including warningagainst the handling of machinery, driving, or engaging in any occupationin which you can be injured. So, to that extent, this concern isn'tnew."

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