Doctors battle to beat the spread of sundown blues

Most people have heard of the winter blues, or Seasonal Affective Disorder, the medical condition brought about by long nights and little sunlight. But studies have now identified Sundown Syndrome, a year-round condition affecting the elderly and linked to the hours before sunset.

Sundown Syndrome involves increased levels of agitation and confusion in the late afternoon and early evening, according to a report published in the November edition of Nursing Standard magazine.

The syndrome is widely recognised but under-researched in Britain. In the United States it has been acknowledged as a medical condition in several areas of health care, including nursing homes, acute and psychiatric hospitals.

The latest research, carried out last May, involved observation of 52 residents of a nursing home in Morecambe, Lancashire. The residents, who had an average age of 86, were monitored between 10am and midday and 4pm and 6pm. The report found that 20 of the residents showed greater mental impairment and levels of confusion during the afternoon hours over at least a two-day period.

"They became restless, tapped their feet and fingers, pulled at their clothes, some rocked back and forth and others would scratch themselves," said the study's author, Lee Drake, an independent researcher and psychological trainer. "These symptoms were markedly worse in the evening than they were in the morning.

"Previous studies have suggested that it is only people suffering from dementia or Alzheimer's who are vulnerable to this syndrome, but most of the residents in this case who showed signs of distress still had all their cognitive faculties," said Mr Drake.

"This would suggest it is an affective disorder and so could be also apparent in children and other adults," he said.

The research has been welcomed by Help the Aged, which says it may help to remove some of the stigma around the elderly. "We don't like the way elderly people can be mis-diagnosed as having dementia," said Kirsty Fyfe, a spokeswoman. "This research suggests there may be other factors to explain some behaviour."

The influence of sunlight on mood has been well established and Seasonal Affective Disorder (SAD) is a recognised condition. In cases of SAD, the imbalance in brain chemicals is triggered by the shorter daylight hours and the lack of sunlight in winter. Ranging from mild blues to severe clinical depression, in 85 per cent of cases SAD symptoms respond to an hour or two of daily exposure to bright light.

In contrast, health experts suspect Sundown Syndrome may also have a psychological explanation. "This is a new subject. In 10 years we may be able to say sundown syndrome is an affective disorder," said Dr Lance Workman, a biological psychologist at the University of Glamorgan.

"We all feel fresher in the morning. We have had an evolutionary history and we feel safer in the daylight. At night we are less able to detect predators. Elderly people are more prone to depression, partly because they may feel their lives are coming to an end."

Dr Ian Rodin, a lecturer in psychiatry at Southampton University, said it was not unusual for people to feel worse at certain times of day. "It's well known that the time of day can affect how people feel. Our body has daily biorhythms and their patterns are partly dictated by when the sun comes up and when it goes down.

"Hormone and chemical secretions are influenced by the body clock and one of the things that affects our body clock is daylight. At the end of the day people start to wind down, perhaps are starting to worry about not being able to sleep."

Mr Drake also suggested that the ambience of nursing homes may exacerbate the problem. "A lot of care homes are very dreary. The onset of darkness can be a depressing time in a nursing home. Most of the activity of the day has gone and most staff have left. The residents are hanging around waiting for bed.

"A simple solution may be to improve lighting in care homes by installing fluorescent tubes rather than the traditional dimmed lighting."

It was a point supported by Abigail Bennett of Age Concern. "Older people in care homes are twice as likely to become depressed as people of the same age living in their own home," she said. "Depression is seen as an inevitable part of old age rather than a health problem that is treatable."