Sundowning Syndrome

What is Sundowning syndrome?

Sundowning syndrome is a condition, in which neuropsychiatric symptoms are rising up after sunset or late afternoon, evening or at night. This syndrome specifically occurs in elderly patients with prolonged suffering and long term admitted in a healthcare institution or patients with cognitive impairment, dementia. Sundowning syndrome in elderly patients may or may not associated with dementia1,2,3.


A wide variety of symptoms is associated with Sundowning syndrome, which may not be specific for this syndrome only, as these symptoms are also manifested with Parkinson’s disease, dementia, delirium, and sleep disturbances. The symptoms include

  • Confusion
  • Disorientation
  • Anxiety
  • Agitation
  • Mood swings
  • Aggression
  • Abnormally demanding attitude
  • Pacing
  • Wandering
  • suspiciousness
  • Restlessness
  • Resistance to redirecPrint screaming
  • Yelling
  • Visual and auditory hallucinations
  • Confusion
  • Disorientation
  • Nocturnal delirium
  • Screaming
  • Delusional thinking
  • Moaning
  • Wandering
  • Drowsiness
  • Confusion
  • Ataxia
  • Falling

The main difference of sundowning with other neurodegenerative diseases is all the disruptive behaviors arises in the late afternoon, evening or at night. Often caregivers face problems to deal with the patient after the onset of symptoms. Institutionalization of elderly patients with dementia often gets sundown syndrome1,4.


Researchers are still working to find out the exact cause of sundown syndrome. Different medical kinds of literature propose different theories to explain the etiology of sundown syndrome and according to these theories, the factors which influence the etiology are physiological, psychological, and environmental1,5.

Triggering factors

Excessive Activity

Some researchers propose that excessive activities in a day causes fatigue and may cause increased stress and leads to anxiety and confusion.


Fatigue often resultant from exhaustion and end of the day when no work remains may trigger sundown syndrome.

Dim Light

After sunset, the light becomes dim and gloominess becomes a challenge for vision and triggers the onset of symptoms related to sundown syndrome.

Hormonal Imbalances

Hormone imbalances negatively influence internal biological clock and that hampers cognition, body balancing, sleep cycle and trigger sundown syndrome.


Seasonal alteration also affects moods. In winter less exposure to natural sunlight often causes depression.1,6


Sundowning Syndrome diagnosis is completely based on clinical presentation, which is characterized by the abnormal behavioral approach, cognition impairment and that affect activity of the suffer. All the negative influence are temporary, and initiate after sunlight become dimmed. Different medical literature mentioned that electrophysiologic studies were performed in Sundowning Syndrome, but no comprehensive report found on the diagnosis of sundowning syndrome1.

Differential Diagnosis

Differential diagnosis performs to exclude the chance of symptoms are not aroused due to delirium. The differential diagnosis requires to perform because both sundowning and delirium possess the similar type of symptoms, but the time of onset of symptoms in sundowning syndrome mainly arise after sunset or dimming of daylight. Another basic difference between sundowning and delirium is a time frame of the symptoms persistence and sundowning syndrome symptoms are usually temporary in nature.

Medical history of the affected patient with sundowning shows the prior presence of some degree of cognitive impairment. Some clinician believes nocturnal delirium is a pre-indication of delirium progression. Researchers also reported that coexistence of sundown and dementia in sundown affected patient and delirious is common in sundown episode, whereas all demented patient may not have sundowning syndrome5,7.


Sundowning Syndrome

Routine Lifestyle

Routine lifestyle restricts sudden change in the daily rhythm and that also not produce exhaustion. The vulnerable individual has a constant mental status and may not enhance stress level to produce anxiety and/or confusion. Sundowning syndrome affected individual usually has not a mental state to handle the surprising situation. Avoid daily sleeping and only two vigorous activities can be plan per day.

Diet management

Some food items like caffeine and excessive sugar-containing drinks and foods can trigger the Sundowning syndrome and should avoid these especially late in the day.

Noise control

The activities or devices which produce noise should avoid at late afternoon or evening, which include put o television, radio or other domestic noise producing amusement devices and also avoid visitors come in evening. The affected patient should keep some isolated room, where the calm environment maintenance can be possible.

Light Therapy

All spectrum light rays are provided through a light box device, which may minimize the sundowning syndrome symptoms, including depression. The room where the patients stay should have well supply of light and even during sleep at night lit up night light, which decreases the chance of nocturnal delirium.


Some medications like antidepressant or sedatives can help to control depression and sleep disorders in sundowning syndrome. But the selection of medication is very important, because some drugs may cause disruption of sleep pattern or provide imbalance energy level.

Dietary Supplementation

Some dietary supplementation may useful to control the sundowning syndrome symptoms like herbs ginkgo Biloba can help to control the symptoms of dementia and vitamin E supplementation also control symptoms of sundowning syndrome. Hormone supplement like, Melatonin assists in sleep regulation6.


  1. Nina Khachiyants, David Trinkle, Sang Joon Son, Kye Y. Kim; Sundown Syndrome in Persons with Dementia: An Update; Psychiatry Investig. 2011 Dec; 8(4): 275–287. Published online 2011 Nov 4. doi: 10.4306/pi.2011.8.4.275; Online available at
  2. Cameron DE. Studies in senile nocturnal delirium. Psychiatr Q. 1941;15:47–53.
  3. Kim P, Louis C, Muralee S, Tampi RR. Sundowning syndrome in the older patient. Clin Geriatr. 2005;13:32–36.
  4. Volicer L, Harper DG, Manning BC, Goldstein R, Satlin A. Sundowning and circadian rhythms in Alzheimer’s disease. Am J Psychiatry. 2001;158:704–711.
  5. Duckett S. Managing the sundowning patient. J Rehabil. 1993;1:24–28.
  6. Sundowners Syndrome: Triggers & Management;
  7. Lipowski Z. Delirium: Acute brain failure in man. Springfield, IL: Charles C Thomas; 1980.

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