Is there a relationship between anxiety, depression and cognitive processes in the elderly?
This was a research question that occupied Sherry A. Beaudreau and Ruth O'Hara from Stanford University School of Medicine and the Sierra Pacific Mental Illness, Research, Education and Clinical Center (MIRECC) at the Veterans Affairs Palo Alto Health Care System.
Unfortunately, the answer is the classic, "it depends."
They found that if you take 'anxiety' out of the patient, but keep 'depression' in, you get no difference in cognitive processing -- suggesting that depression itself is not a major contributor to reduced mental performance.
But if you have an anxious elderly adult, either with or without depression, you will also have someone whose mental performance is reduced.
Personally, I'm not sure that you can totally separate 'anxiety' from 'depression' -- my personal experience is that anxiety is nearly always a component of depression, or at least a close travelling companion.
To be fair to Beaudreau and O'Hara, they do note that their sample of 102 community-dwelling older adults were well-educated and also self-reported a mild, not major, state of depression. Had the sample been taken from a population under the care of psychiatrists, it may well have shown similar results to previous studies of such patients and reported impairment of memory and a reduced ability to rapidly shift attention (Beaudreau and O'Hara cite studies from Butters et al., 2004 and Mantella et al., 2007 for those interested in finding out more).
Perhaps the 'take away' from the research is that if you are responsible for or have an elderly relative yourself who is reporting mild depression (which the vast majority of the elderly do), and you witness a slowdown or impairment in their mental faculties that cannot be considered part of 'dementia' or Alzheimers, then have a look at what if any anxiety-producing stressors they have in their environment, or in their inner-world.
Helping to reduce their anxiety, whilst still acknowledging and accepting their depression, may go some way to helping them restore their mental performance.
Beaudreau, S.A., & O'Hara, R. (2009). The Association of Anxiety and Depressive Symptoms With Cognitive Performance in Community-Dwelling Older Adults. Psychology and Aging, 24, 2, 507-512
Butters, M. A., Whyte, E. M., Nebes, R. D., Begley, A. E., Dew, M. A., Mulsant, B. H., et al. (2004). The nature and determinants of neuropsychological functioning in late-life depression. Archives of General Psychiatry,61, 587-595.
Mantella, R., Butters, M. A., Dew, M. A., Mulsant, B. H., Begley, A. E., Tracey, B., et al. (2007). Cognitive impairment in late-life generalized anxiety disorder. American Journal of Geriatric Psychiatry, 15, 1-7.
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