NEW YORK (Reuters Health) - People taking antidepressant medication may find their driving skills impaired, German researchers warn.

"Psychomotor disturbances can frequently be found in depressed patients and may have an important influence on the ability to drive," Dr. Alexander Brunnauer and colleagues point out in the Journal of Clinical Psychiatry. "Additionally, effects of sedation, as seen with some antidepressants, probably impair driving performance."

Brunnauer, of the Academic Hospital of Psychiatry, Psychotherapy, and Neurology in Wasserburg/Inn, and his associates examined the effects of antidepressant treatment on psychomotor functions related to driving skills in 100 inpatients with major depressive disorder.

The following abilities were measured according to the German guidelines for road and traffic safety: visual perception, reaction time, selective attention, vigilance, and stress tolerance.

No clinically relevant psychomotor disturbances were seen in 24 percent of the patients. Mild-to-moderate impairments were observed in 60 percent of patients, and approximately 16 percent of subjects had severe impairments in psychomotor functions related to driving abilities.

Compared with patients treated with older types of antidepressants called tricyclics, those on the newer SSRI-type had altogether better test performance. The most pronounced differences were observed in measures of reactivity, stress tolerance, and selective attention.

"Antidepressants seem to affect fitness to drive differently in depressed patients and thus physicians should be concerned about traffic safety when prescribing antidepressants," Dr. Brunnauer's team concludes.

"The great variability within treatment groups indicates that counseling patients with respect to driving safety must be carried out individually," they advise.