Not new, it is all over the literature but no-one seems to know the cause.
As to the term, "sundowning", this is misleading, it appears that the
condition can arise in afternoon and is related to fatigue. I'm thinking it
may relate to central fatigue combined with a stress response induced by
overall fatigue. In dementia individuals, this may create agitation and
restlessness, though violence seems to be a real problem with it. I was
thinking along the lines of light, circadian rhythms but feel the effect is
too pronounced for a circadian influence. However, recent studies have
indicated that bright light therapy is useful for some dementias. At a
guess, excess nore via stress response without adequate Da modulation.
"Emma Chase VanCott" <7elc at qlink.queensu.ca> wrote in message
news:b5v9ns$jj9$1 at knot.queensu.ca...
> In sci.med.psychobiology John H. <johnh at faraway.xxx> wrote:
> : Recently a friend of mine starting working in a dementia ward for
> : demented individuals. She was advised by other staff that to be careful
> : after sundown because many of the patients become violent and extremely
> : difficult to control. I'm mystified by this, just wondering if anyone
> : has noticed this in severe dementia
>> Sundowning is not some sort of "new" discovery.
>> Geriatric psych. literature is rife with references to this phenomenon.
>> There are various strategies. Keep the blinds closed, discourage
> daytime napping to prevent insomnia, etc.
>> Light therapy would be an idea. Keep in mind that it likely must mimic
> sunlight and therefore be full-spectrum, and of an adequate LUX (units of
>> Perhaps it is an SCN (suprachiasmatic nucleus) deterioration thing.