NEW YORK (Reuters Health) — Antidepressant use is independently associated with gait impairment, but depressive symptoms are not, a new study of nearly 2,000 community-dwelling older adults demonstrates.

"Several studies have linked antidepressant use to an increased risk of falls, fractures, and frailty," Dr. Orna Donoghue of The Irish Longitudinal Study on Ageing (TILDA) at Trinity College Dublin and colleagues note in their report. "Gait deficits associated with antidepressant use could potentially mediate this relationship, and the paucity of current research highlights the need to examine this further."

The findings were published online May 2 in the American Journal of Geriatric Psychiatry.

Earlier studies linked depression to an increased risk of falls and gait impairment among older adults. Reports on the effects of antidepressants on gait impairment had been small and produced conflicting results, Dr. Donoghue and her colleagues write.

To better understand how depression, antidepressants, and gait impairment are related, the researchers evaluated 1998 adults ages 60 and older who were participating in the TILDA study. Of those, 7.8% had clinically relevant depressive symptoms and 4.9% were taking antidepressants.

Study participants had completed either the single or dual task gait assessment with a minimum of eight steps. Dual task assessment involves having the person walk while reciting alternating letters of the alphabet.

Individuals with depressive symptoms walked 7 centimeters per second (cm/s) slower on the single task gait test and 4 cm/s slower on the dual task gait test, compared to study participants without symptoms of depression. Participants on antidepressant therapy walked 14 cm/s slower on both gait tests than those who were not on antidepressants.

Regression analyses showed that while being on antidepressant therapy was independently associated with gait impairment, having depressive symptoms was not.

There are many possible explanations for the observed relationship between antidepressant use and gait impairment, the researchers note. For example, the drugs have a number of side effects that can affect gait, such as muscle rigidity and drowsiness.

"Our results suggest that a gait and falls assessment may be a useful addition when assessing older adults with depressive symptoms, especially when antidepressants are prescribed," Dr. Donoghue and her team state. "This is particularly pertinent given the increased prevalence of antidepressant treatment in recent years."

The findings also underscore the importance of exercise interventions to prevent falls and help older adults maintain their independence, the researchers add, noting that these interventions have "both psychological and physiological benefits."