We All Sundown, Don't We?

Mark E. Williams, MD


December 15, 2021

Mark E. Williams, MD

When I was a geriatric fellow in the early 1980s, I trained in a very large facility, with more than 535 beds, in Rochester, New York. I cared for several patients who regularly became confused late in the day, toward evening. At the time, I wondered about the mechanism of what we now call sundowning, and what we could do to minimize the distress of the person experiencing it.

I met with the reference librarian who helped me to perform a literature search on sundowning. To my complete surprise, we found only one article, from 1941 ("Studies in senile nocturnal delirium" by D. Ewen Cameron), that appeared in Psychiatric Quarterly. In retrospect, the paucity of literature probably related to the fact that the term was coined in 1987, 7 years after I started my fellowship. I made a copy of Cameron's article and put it in my briefcase to read the next day during a flight to a professional meeting.

A Small but Illuminating Study

On the return flight I re-read the article. The author was systematic, logical, and brilliant. He first wondered if sundowning was due to darkness or if it was simply related to fatigue at the end of the day. Sixteen people with severe dementia who were prone to sundowning were placed in a dark room early in the day and every one of them showed signs of increasing delirium. The delirium reversed when they were brought back to a lit area.

Then Cameron sat each subject in the center of their room and had them point to familiar objects such as the bed, table, mirror, door, window, and nightstand. Some objects were behind the subjects and some to either side. He made notes on where they pointed. He then blindfolded the subjects (sheer genius) and every 15 minutes for an hour, he asked them to point to the location of the items in the room.

Thirteen out of the sixteen subjects progressively displaced all of the objects rostrally. Of interest, when the blindfolds were removed, the subjects were not distressed by where they thought things were in the dark and where they actually were. Cameron hypothesized that the nocturnal delirium represents the conflict experienced between where a person thinks an object is in the dark and where it actually is.

Babies Sundown Too!

My contemplation of the Cameron article during the flight was interrupted by an infant who was sitting on his mother's lap, crying and screaming. The mom looked over at me and said, "I am really sorry, but he always gets grumpy in the late afternoon." I gazed up the aisle and saw the flight attendants passing out coffee and little bottles of alcohol. I had an epiphany: We all sundown!

People go to bars for happy hour; we drink coffee or afternoon tea for a pick-me-up. Most of us can compensate for our evening delirium, but people with dementia cannot. Perhaps it is the combination of reduced lighting and the time of day when our cortisol levels are dropping. Come to think of it, I don't recall seeing the sundowning phenomenon in any of my patients who were taking prednisone or hydrocortisone.

Upon Reflection…

My sundowning observations on the airplane made me realize that we all sundown — it's just that most of us can compensate for it. Each of us has had the experience of waking up in an unfamiliar bed and wondering for a split second, Where am I? Imagine not being able to reconcile your location for longer than that second.

You would think that the science of sundowning would be much more advanced 80 years after Cameron's brilliant insight. And yet, a recent review of the literature would suggest that it has not advanced all that much. There is disappointingly little new information on sundowning in the wake of Cameron's work. Perhaps researchers should focus on these compensatory mechanisms. Additional research would enable us to get a better handle on sundowning and thus provide better care to our geriatric patients.


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