Depression linked with impaired spatial ability

Depression has a detrimental effect on people's ability to find their way around, according to researchers. Husseini Manji and colleagues compared the performance of 30 depressed patients and 19 healthy controls on a virtual reality spatial navigation task. The participants had to navigate their way around a virtual town, in a task that resembled a first-person perspective video game. Participants familiarised themselves with the town one day, and then the actual testing, which involved finding locations in the town, took place three days later.

The performance of the depressed patients was impaired relative to the healthy controls. Moreover, the more depressed a patient was (as measured by a psychiatric rating scale) the worse they tended to perform at the navigation task. Performance did not vary according to the kind of depression participants were suffering from: uni-polar or bi-polar.

The patients and controls did not differ on IQ or on a traditional pen and paper spatial task, suggesting such tests are not sensitive enough to pick up on the spatial deficit revealed by the current virtual reality task.

Past research has shown the virtual reality navigation task used here is associated with neural activity in the hippocampus. Meanwhile other studies have reported reduced hippocampal volume in patients with depression, so it's tempting to conclude that the patients were impaired at the navigation task because of hippocampal abnormalities. However, further research is needed to confirm this.

On a related note, stimulating neural regrowth in the hippocampus could be a new target for anti-depressants.

Further reading

Gould, N.F., Holmes, M.K., Fantie, B.D., Luckenbaugh, D.A., Pine, D.S., Gould, T.D., Burgess, N., Manji, H.K. & Zarate, Jr., C.A. (2007). Performance on a virtual reality spatial memory navigation task in depressed patients. American Journal of Psychiatry, 164, 516-519.