Sundowning

Key takeaways

Sundowning belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Sundowning to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Sundowning from memory before moving on to harder problems.

Reference excerpt

Sundowning, or sundown syndrome, prevalent among people with some form of dementia, is characterized by increased confusion and restlessness beginning in the late afternoon and early evening. The term sundowning was coined by nurse Lois K. Evans in 1987 due to the association between the person's increased confusion and the setting of the sun. For people with sundown syndrome, a multitude of behavioral problems begin to occur and are associated with long-term adverse outcomes. Sundowning seems to occur more frequently during the middle stages of Alzheimer's disease and mixed dementia and seems to subside with the progression of the person's dementia. People are generally able to understand that this behavioral pattern is abnormal. Research shows that 20–45% of people with Alzheimer's will experience some variation of sundowning confusion. However, despite lack of an official diagnosis of sundown syndrome in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), there is currently a wide range of reported prevalence.

Relevance The following social, economic, and physiological adverse outcomes are correlated with individuals affected by sundowning and their caregivers:

Long-term admission to psychiatric care facilities. Prolonged hospital admission with recurrent visits that increase financial burden. Steeper cognitive decline in Alzheimer's disease. Decreased quality of life. Increased stress and burnout of caregivers due to the timing of sundowning symptom onset.

Symptoms Symptoms are not limited to but may include:

Increased general confusion as natural light begins to fade and increased shadows appear. Agitation and mood swings. Individuals may become fairly frustrated with their own confusion as well as aggravated by noise. Individuals being found yelling and becoming increasingly upset with their caregivers are not uncommon. Mental and physical fatigue increase with the setting of the sun. This fatigue can play a role in the individual's irritability. An individual may experience an increase in restlessness while trying to sleep. Restlessness can often lead to pacing and or wandering which can be potentially harmful for an individual in a confused state. Hallucinations (visual and auditory) and paranoia can cause increased anxiety and resistance to care.

Causes While the specific causes of sundowning have not been empirically proven, some evidence suggests that circadian rhythm disruption increases sundowning behaviors. In humans, sunset triggers a biochemical cascade that involves a reduction of dopamine levels and a shift towards melatonin production as the body prepares for sleep. In individuals with dementia, melatonin production may be decreased, which may interrupt other neurotransmitter systems. Other causes or precipitating factors that may lead to sundown syndrome may include hormonal changes, disturbances in REM sleep, individual and/or caregiver fatigue, inappropriate medication use, or being predisposed to behavioral disorders from chronic neurological diseases. Resources in an institution's environment can also play a role as a symptom trigger. A reduced number of staff in the evening can be attributed to more unmet needs and a lower threshold for agitation for individuals with sundown syndrome. Sundowning should be distinguished from delirium, and could be presumed to be delirium when it appears as a new behavioral pattern until a causal link between sunset and behavioral disturbance is established. People with established sundowning and no obvious medical illness may be suffering from impaired circadian regulation, or may be affected by nocturnal aspects of their institutional environment such as shift changes, increased noise, or reduced staffing (which leads to fewer opportunities for social interaction). Delirium is generally an acute event that can span hours to days.

Connection to Alzheimer's disease It is thought that with the development of plaques and tangles associated with Alzheimer's disease there might be a disruption within the suprachiasmatic nucleus (SCN). The SCN is located in the hypothalamus and is associated with regulating sleep patterns by maintaining circadian rhythms, which are strongly associated with external light and dark cues. A disruption within the suprachiasmatic nucleus would seem to be an area that could cause the types of confusion that are seen in sundowning. However, finding evidence for this is difficult, as an autopsy is needed to analyze this disruption properly. By the time a person experiencing Alzheimer's has died, they have usually surpassed the level of brain damage (and associated dementia) that would be associated with sundowning. This hypothesis is, however, supported by the effectiveness of melatonin, a natural hormone, to decrease behavioral symptoms associated with sundowning. The pineal gland produces melatonin when signaled by the SCN to help maintain circadian rhythms. Melatonin supplementation can be administered to older adults as their natural hormonal production decreases over time. Serotonin has also been observed to potentially have a key role in the regulation of circadian rhythm as research has shown that serotonergic agonism in the SCN results in "phase shifts" in portions of the light-dark cycle. In addition to the effects on circadian rhythm, serotonin is also known to be involved in the regulation of aggression. Due to the serotonergic signaling deficiencies of Alzheimer's disease, it has been commonly reported that deficiencies in serotonin have been associated with worsening circadian rhythm or aggression.

Risk factors Elderly people often experience multiple comorbidities that may contribute to the phenomenon of sundowning syndrome through neurodegeneration.

Neurological disorders: Alzheimer's disease, Parkinson's disease, Huntington's disease, Lewy body dementia, fronto-temporal dementia, subcortical dementia. Neurobehavioral disorders: anxiety and depression. Cerebrovascular disease risk factors: hypertension, smoking, obesity. Genetic predisposition: presence of the ApoE4 allele has associations with sundown syndrome in people experiencing Alzheimer's disease.

Treatment Scant clinical trials exist to guide treatment. Current treatment proposals have limited justifications for their use. Treatment of sundown syndrome may vary based on when agitated behavior is observed throughout the day.

… excerpt ends here. Continue reading the full article.

Worked examples

Example 1 — a first encounter with Sundowning

Start with the simplest possible case. Write down what Sundowning claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Sundowning before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Sundowning ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Sundowning

In research: Sundowning appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Sundowning in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Sundowning is common in secondary-school and first-year university syllabi. It links to neighbouring topics Alzheimer's disease, Circadian rhythm, Delirium, so understanding it makes those chapters shorter.
In everyday life: Look for Sundowning outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Sundowning in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Sundowning means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Sundowning out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Sundowning in simple terms?

Sundowning, or sundown syndrome, prevalent among people with some form of dementia, is characterized by increased confusion and restlessness beginning in the late afternoon and early evening. The term sundowning was coined by nurse Lois K.

Why does Sundowning matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Sundowning?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Sundowning.