Sundowning in elderly dementia patients: Causes, symptoms, and remedies

sundowning in demetia patients Sundowning is commonly seen in dementia patients. The term refers to changes in behavior that occur in the evening when the sun sets. Patients may become more agitated, aggressive, or confused as the night comes. This is often seen in more severe cases of dementia as the disease progresses. Sundowning may be a result of disturbances to the patient’s 24-hour ‘body clock’, loss of daytime routine, insufficient or disturbed sleep, too little or too much light, prescribed medication, and excessive disturbing noise.

A study has uncovered a possible explanation why some patients are susceptible to sundowning. Lead author of the study Tracy Bedrosian said, “There have been a few clinical studies documenting sundowning, but until now there hasn’t been research in animals to see what’s going on in the brain to explain this.”


The study showed that aged mice showed much more activity and anxiety-like behaviors before their normal bedtime, compared to middle-aged mice – similarly to sundowning in humans.

In these aged mice, the researchers detected changes in the brain parts responsible for attention, emotions, arousal, and other behaviors associated with sundowning in people.

Coauthor Randy Nelson added, “Some people have argued that sundowning could be explained just by a buildup of frustration of older people who couldn’t communicate their needs over the course of the day, or by other factors. But our findings suggest there is a real phenomenon going on here that has a biological basis.”

The researchers also found greater expression of the enzyme acetylcholinesterase prior to bedtime – high levels of this enzyme are associated with anxiety.

Many dementia patients are prescribed medicine to control acetylcholinesterase levels even though there was little evidence that it has any effect on sundowning. The present study actually explains the calming effect of these medicines on patients prone to sundowning.

Bedrosian added, “All of these results converge to suggest there are changes in the cholinergic systems of aged mice that may be contributing to the anxiety and agitation symptoms that we documented.”

Further research is needed on the treatment of the cholinergic dysfunction as a means of further improving the symptoms of sundowning.

Causes and symptoms of sundowning

The exact cause of sundowning is still unclear, but researchers speculate there are many factors involved. Some of these factors are extreme fatigue, hunger or thirst, depression, pain, boredom, or sleep problems.

Triggers of sundowning symptoms may include less light and more shadows in the house, which can lead to confusion and fear, or trouble separating dreams from reality, which can lead to disorientation.


Symptoms of sundowning include:

  • Agitation
  • Anxiety
  • Restlessness
  • Irritability
  • Confusion
  • Disorientation
  • Suspiciousness
  • Yelling
  • Pacing
  • Hallucinations or delusions
  • Mood swings

Tips to reduce sundowning in elderly

artificial lightIf you a caregiver of a dementia patient suffering from sundowning, there are some things you can do to improve care and effectively handle this type of behavior. Here’s what you can try to cope with sundowning:

  • Give the patient something meaningful to do in the evening.
  • Set up a relaxing activity in the late afternoon/early evening.
  • Think about the patient’s day. Can their behavior be explained by something they may need like food or water? Are they in pain or do they have to use the bathroom? Addressing these needs can help prevent sundowning.
  • Minimize the patients’ daytime naps if they are having difficulties falling asleep.
  • Have the patient exercise as it can improve sleep.
  • Improve their sleeping environment – eliminate caffeine, ensure the room is cool enough and dark.
  • Keep appropriate lighting – a room that is too dark can cause distress.

By following some of these tips, you can have greater success in reducing the incidences of sundowning and better managing the symptoms.

Author Bio

Emily Lunardo studied medical sociology at York University with a strong focus on the social determinants of health and mental illness. She is a registered Zumba instructor, as well as a Canfit Pro trainer, who teaches fitness classes on a weekly basis. Emily practices healthy habits in her own life as well as helps others with their own personal health goals. Emily joined Bel Marra Health as a health writer in 2013.


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