Tuesday, 27 March 2007

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.
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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.

Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.

7 comments:

  1. Interesting. Do depressed people do less well at spatial tasks because of brain abnormalities or is it because they are less motivated to do well at these sorts of mental tasks?

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  2. that's a good point rvcanuck. Your question is partially answered by the fact the depressed people and controls were matched for IQ (a detail I've now added to the main text) and by the fact they performed equally well on the pencil and paper spatial task - suggesting they were motivated enough to perform mental tasks.
    Christian

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  3. You might be interested in a new DVD on Depression just released by my company called EVERYTHING YOU ALWAYS WANTED TO KNOW ABOUT DEPRESSION presented by UK Consultant Psychiatrist, Dr Darryl Britto at www.TimeTrappers.co.uk
    Cheers
    John Edmonds
    CEO
    TimeTrappers

    ReplyDelete
  4. I'm really just free-associating here, but is it possible that there is a connection between stress- or depression-related reductions in hippocampal neurogenesis (pretty well documented I believe) and the "spatial map" representations that reside in hippocampus?

    The paper and pencil spatial task may involve more parietal components, whereas navigation is clearly involves a lot of hippocampal computation.

    very cool...

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  5. Could it not just be down to the fact that a person who is depressed has reduced concentration and therefore a reduced capacity to remember

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  6. What affect do you think this would have on architecture and the urban environment?

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  7. This is in regards to whether a person suffering from depression finds city living more difficult than others. Due to the disorientation that can be caused by buildings, streets etc. Perhaps architecture is in a sense increasing the effect of depression in some people?

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