Dementia symptoms ‘are worse’ in spring and winter

DEMENTIA symptoms get better in the summer and autumn, scientists have found in an intriguing discovery which hints at new ways to fight the devastating condition.

Canadian researchers studied more than 3,000 people with an average age of 77 and found their mental function declined by the equivalent of 4.8 years in the spring and winter months. They were also 30 per cent more likely to reach the threshold for cognitive ability where they would be diagnosed with dementia.

Researchers say that screening in winter and spring may be a better way of spotting dementia early as symptoms may be masked in the summer and autumn.

Writing in the journal PLOS Medicine, Dr Andrew Lim of the University of Toronto, said: “We found that older adults with and without dementia have better thinking and concentration in the late summer and early fall than in the winter and spring.

“By shedding light on the mechanisms underlying the seasonal improvement in cognition in the summer, these findings also open the door to new avenues of treatment for Alzheimer disease.”

There are more than 850,000 people living with dementia in Britain and the figure is expected to rise to 1 million by 2025. But there are still no treatments or a way of halting or reversing the symptoms.

Scientists are unsure why cognition improves in the summer and autumn but says it shows that the brains of people with dementia are still capable of improvement.

As well as cognitive improvements, researchers also found there were changes in the levels of Alzheimer’s related proteins in the cerebrospinal fluid and the brain.

The phenomenon may be caused by differing levels of vitamin D, sex hormones and melatonin, which shift with the seasons, scientists have suggested. And they speculated that more light and warmer temperatures could also be helpful, as well as increased social interactions in the summer months. “If true, then interventions such as phototherapy or temperature modification may be effective in sustaining this peak year-round,” the authors conclude.