Gait characteristics in patients with major depression performing cognitive and motor tasks while walking.

Depressed patients demonstrate alterations in motor and cognitive functioning that can affect their adjustments to the variations in everyday life environment. The objective was to explore gait parameters and variability of patients with major depressive disorder in dual task walking situations. Eight patients and 20 healthy controls performed motor, mental and combined motor+mental tasks while walking. Calculated parameters were cycle time, stride length, swing time, double support time and their coefficients of variation (CV). Patients demonstrated greater gait variability (swing time CV) than controls during baseline walk (t(26)=2.64, p<0.05) and motor dual task (t(26)=3.68, p<0.05). Moreover, the transition from mental to combined task decreased stride length (M=126.48±15.35 and M=121.19±13.55, p<0.001) and increased double support time (M=0.266±0.072 and M=0.287±0.076, p<0.01) only in controls. Also, gait variability increased in controls during the combined task, while remaining the same or decreasing in patients. Tasks that required greater cognitive involvement affected gait variability in patients more than controls, but only up to a certain level, after which patients׳ stability appeared unaffected by the increase of cognitive demand. This could be explained by a tendency of patients to neglect complex cognitive tasks while walking in order to preserve stability and prevent possible falls.