Winter time is here, the days have become shorter and the evenings darker. For most of us it’s the signal of cosy nights in and that Christmas will soon be upon us.

But for people with dementia this shift can have a dramatic effect on their behaviour.

Light plays a huge role in our sleep cycles. Everyone has an internal 24-hour 'body clock' which tells our bodies when to sleep. With the clocks going back recently we now have less light in the evenings, this can cause a disturbance to someone’s internal clock and for people with dementia can trigger sundowning.

Sundowning may be caused by a number of reasons including loss of routine at a previously busy time of day, too little or disturbed sleep or too little or too much light. It can cause people to become of agitated, aggressive or confused during the late afternoon or early evening.

For people with dementia disturbances to their body clocks can be caused by the physical changes to the brain that happen as a direct result of the condition, however changes in timings caused when daylight saving time ends could further complicate things. It is believed that overstimulation and exhaustion caused by the changes from daylight saving time affect the brain and many carers have noticed that the symptoms of sundowning get much worse after the clocks change.

Alzheimer’s Society recommends that you try to give the person something meaningful to do at the time of day that they are most affected, using past activities as a guide. Consider planning quiet and relaxing activities for late afternoon/evening and consider minimising daytime naps.

Exercise can be beneficial for helping someone to sleep and we always recommend people try to remain physically active after diagnosis to help them to continue to live well with the condition.

For further information or advice call the National Dementia Helpline on 0300 222 1122 or visit