Sundowning is a term broadly used to describe a set of behaviours occurring in people with or without dementia, which commonly presents later in the afternoon, evening and late at night. Behaviours include confusion, disorientation, anxiety, agitation, yelling and calling out, aggressive outbursts (verbal and/or physical), pacing and wandering. 

While not a formal psychiatric diagnosis, the prevalence of sundowning is well recognised and well documented. Some literature suggests rates of sundowning for elderly persons with cognitive impairment such as dementia are as high as 66%. Sundowning can be very challenging to manage and have a significant impact on the person and their loved ones/carers who are supporting them.

A number of theories exist regarding the possible reason/s for sundowning, though none have demonstrated a high level of scientific evidence to date. Commonly held beliefs about the prevalence of sundowning in people with dementia include:

·         Problems with circadian rhythm (the internal body clock) and difficulty differentiating between dream state during sleep and reality

·         Misinterpretation of input (light and shadows) which increases confusion, fear & agitation

·         Less stimulation after dark to act as a distraction

·         A consequence of mood symptoms or medications wearing off in the afternoons

·         Unmet physiological needs – hunger, thirst, pain, over tiredness

Sensory Modulation Brisbane has considered sundowning with a sensory lens and whether these behaviours are in fact a consequence of sensory overload. This could apply to people with dementia, Autism Spectrum Disorder and other conditions.

Sensory overload occurs when a person experiences too much sensory input for their system (too loud, too busy, too bright, too fast or too intense) resulting in increased feelings of distress and overwhelm. Think about a baby who has been too stimulated through the day, they will often become overloaded, upset and are much more difficult to settle in the evening. For a person with dementia, sensory overload will have a similar effect and thus could be a significant factor in the occurrence of sundowning behaviours. Some literature has suggested that agitation could be a behavioural response to sensory overstimulation and wandering may be an attempt at self- regulation.

People with cognitive impairment like dementia often experience sensory overload due to difficulties with:

·         understanding their unique sensory needs and preferences

·         being able to regulate sensory input throughout the day, for example turning down the volume, changing the temperature, opening or closing the door or window covers or even their choice of meal flavours and textures.

·         being able to communicate their sensory needs to others, for example telling others when they feel uncomfortable or in pain or timely requests to change sensory input in their environments

To help manage behaviours related to dementia, non-pharmacological measures including environmental assessment and modifications are recommended. Sensory modulation is therefore an effective means of reducing the prevalence and challenging consequences of sundowning behaviours, by actively managing and addressing the experience of sensory overload. Examples of sensory modulation strategies include:

1.       Dialling down sensory input into the afternoon and evening, such as –

·         Slowly turning down light levels

·         Reducing visual movement and business in the environment, including turning off the TV.

·         Reducing sound levels/volume, or use of gentle white noise in background to filter out unwanted sound

·         Eliminate unwanted scent with products such as nil odour, or using a familiar scent known to be comforting to the person (be mindful not to diffuse scents in public/common spaces as other people may not prefer/like this smell)

2.       Use of individually preferred sensory input at the times sundowning can occur, such as –

·         Gentle movement like rocking, stretching or swaying

·         Deep pressure like weighted items

·         Comforting touch like a warm bath or heat pack, snuggly throw rug, familiar tactile items to explore in hands.

3.       Engagement in familiar, calming routines and activities in the afternoon and evenings to increase feelings of comfort and stability and reduce experience of unfamiliar and novel sensory input.

4.       Access to a book or digital frame with familiar and soothing pictures of family, friends, pets, places.

References

(2011). Khachiyants, N; Trinkle, D; Son, SY & Kim, KY.  Sundown Syndrome in Persons with Dementia: An Update. Psychiatry Investigation, 8:275-287

(2022). Rhodus, E; Hunter, E; Rowles, G. Sensory Processing Abnormalities in Community-Dwelling Older Adults with Cognitive Impairment: A Mixed Methods Study. Gerontology and Geriatric Medicine. 8, 1-11  https://doi.org/10.1177/23337214211068290

 Link to Online Training – How to Use Sensory Modulation with Aged Care Residents

Sensory Modulation Resource Manual (2017) J O’ Sullivan and C Fitzgibbon.