Sundowning is a pattern of sudden agitation, confusion, and anxiety that typically strikes between 4 p.m. and 6 p.m. in people with dementia. It can also include mood swings, distrust, wandering, and even hallucinations. If you’re caring for someone who becomes a different person as evening approaches, there are concrete steps you can take to reduce the frequency and intensity of these episodes.
What Causes Sundowning
The brain has an internal clock, a small cluster of cells in the hypothalamus, that regulates sleep, wakefulness, and even the tendency toward agitation across the day. In Alzheimer’s disease and other dementias, this clock deteriorates. Recent research has mapped a specific pathway from this clock region through other parts of the hypothalamus that directly modulates aggressive behavior. When the clock malfunctions, the brain loses its ability to keep aggression in check at predictable times, which helps explain why agitation spikes in the late afternoon and evening rather than appearing randomly.
This clock also governs melatonin production, the hormone that signals your body it’s time to sleep. People with dementia often produce less melatonin and produce it at irregular times, which compounds the confusion between day and night. The result is a nervous system that’s simultaneously exhausted and unable to wind down.
Common Triggers to Watch For
Beyond the biological clock dysfunction, several everyday factors can set off or worsen a sundowning episode. Recognizing these gives you specific levers to pull:
- Fatigue. A long or overstimulating day makes evening agitation worse. But so do long afternoon naps, which disrupt nighttime sleep and shift the internal clock further out of alignment.
- Low lighting and shadows. As daylight fades, dim rooms create visual ambiguity. A person with dementia may misinterpret shadows as people or threats.
- Hunger or thirst. If dinner is late or the person hasn’t been drinking enough fluids, basic physical discomfort becomes a trigger the person can’t always articulate.
- Pain or infection. Urinary tract infections are a particularly common and overlooked cause of sudden behavioral changes in older adults. If sundowning appears out of nowhere or dramatically worsens, an underlying infection may be the cause.
- Unfamiliar surroundings. Travel, hospital stays, or even rearranged furniture can strip away the environmental cues a person with dementia relies on to feel safe.
- Boredom and depression. A day with no meaningful activity or social contact can leave the person understimulated and more vulnerable to confusion as the day wears on.
Structure the Day to Prevent Episodes
The most effective interventions happen hours before sundowning starts. Think of your approach as setting up the entire day so the evening goes more smoothly.
Keep mornings active. Physical activity, social interaction, and engagement with familiar tasks during the first half of the day build healthy fatigue that supports a natural transition to rest in the evening. Discourage long naps after early afternoon. A 20-minute doze is fine, but an hour-long nap at 3 p.m. can delay sleep onset and feed into the cycle of nighttime restlessness and daytime drowsiness.
Cut caffeine and alcohol from the afternoon onward. Coffee, tea, cola, and alcoholic drinks all interfere with sleep architecture and can increase agitation. If your loved one enjoys coffee, keep it to the morning hours.
Serve a reliable, predictable dinner at the same time each day, early enough that hunger doesn’t become a trigger. A small, calm snack in the late afternoon can help bridge the gap if dinner is later.
Adjust Lighting and the Home Environment
Bright light exposure in the morning is one of the most studied non-drug interventions for sundowning. Exposure to light above 1,000 lux at eye level, roughly the brightness of being near a sunny window, has been shown to improve nighttime sleep, increase daytime alertness, and reduce evening agitation. Multiple studies using light boxes between 2,500 and 10,000 lux for one to two hours in the morning (typically between 9:00 and 11:30 a.m.) found more consolidated nighttime sleep and more stable daily rhythms. You can achieve this with a commercial light therapy box or simply by arranging time near a bright window or outdoors each morning.
As evening approaches, the goal shifts. Turn on lights before sunset so there’s no sudden transition from daylight to dimness. Close curtains to reduce the visual contrast of darkness outside. Eliminate shadows where possible, especially in hallways and bathrooms. Nightlights in key areas reduce disorientation if the person wakes during the night.
Beyond lighting, reduce noise and clutter. Turn off the TV if it’s adding confusion rather than comfort. Play familiar, soothing music instead. Keep well-loved objects and photos visible, as these serve as anchoring cues that reinforce a sense of safety and familiarity.
How to Respond During an Episode
When sundowning is already happening, your goals narrow: keep the person safe, reduce their distress, and avoid escalation. Three core techniques help.
First, validate their feelings. If the person is anxious or frightened, don’t argue with their perception of reality. Saying “there’s nothing to be afraid of” dismisses what feels very real to them. Instead, acknowledge the emotion: “I can see you’re upset. I’m right here with you.” This doesn’t mean agreeing with a hallucination, just recognizing the feeling behind it.
Second, use distraction. Gently redirect attention to something comforting: a favorite song, a simple familiar activity, a snack, or looking through a photo album. The key is “gently.” Forcing a new activity can increase frustration. Offer rather than insist.
Third, stay calm yourself. People with dementia are highly attuned to the emotional tone around them, even when they can’t follow the words. If you’re visibly frustrated or anxious, it amplifies their agitation. Speak slowly, use short sentences, and keep your body language relaxed. Move slowly. Approach from the front rather than from behind.
Melatonin and Other Treatments
Melatonin supplementation has shown consistent benefits for sundowning in multiple studies. Doses ranging from 3 to 9 mg taken at bedtime have reduced sundowning severity, decreased nighttime activity, and improved sleep quality in people with Alzheimer’s. In one study, seven out of ten dementia patients taking 3 mg at bedtime showed a significant decrease in sundowning and more consistent sleep onset times. Long-term use at 6 to 9 mg over two to three years continued to improve sleep quality without noted complications in one smaller study.
Melatonin is available over the counter, but the right dose and timing matter, and it can interact with other medications common in older adults. It works best as part of a broader strategy that includes light exposure and environmental adjustments rather than as a standalone fix.
Keeping the Person Safe at Night
Sundowning often leads to wandering, which is one of the most dangerous behaviors in dementia. People may try to leave the house to go to a place from their past, like a childhood home or former workplace, and they can become disoriented quickly once outside.
Start by making a list of places your loved one has gone before or might try to reach. This helps you and neighbors know where to look if an episode occurs. Install an alarm system on exterior doors. Products designed specifically for wandering prevention include door alarms, bed and chair alarms, and pressure-sensitive mats that alert you when the person enters an unsafe area of the house.
Hide car and house keys so they aren’t readily accessible. Place locks out of the normal line of sight, such as at the very top or bottom of doors. If the person tends to get up at night, make sure the path between their bed and the bathroom is well-lit and free of tripping hazards.
Tracking Patterns Over Time
Sundowning varies from day to day, and keeping a simple log can reveal patterns you’d otherwise miss. Note what time symptoms start, what happened earlier in the day, what the person ate, how much sleep they got the night before, and what seemed to help or make things worse. Researchers studying sundowning use structured questionnaires that multiply the number of symptoms by how often they occur each week to calculate a severity score. You don’t need a formal scale, but tracking the same basic information over a few weeks often reveals that certain activities, foods, or disruptions reliably precede bad evenings.
This kind of log is also invaluable when talking to a doctor. “Agitation is getting worse” is hard to act on. “Agitation starts around 4:30 p.m. on days when she naps after 2 p.m., and it’s happening four times a week instead of two” gives a clinician something specific to work with.