Severity of Alzheimer's Can Vary by Season

A study published in PLoS Medicine found the cognitive ability of people with Alzheimer's can shift with the seasons, reports HealthDay News . The researchers' analysis of data on about 3,400 people with Alzheimer's in the United States, Canada, and France determined their cognitive ability is better in the late summer and early fall compared to winter and spring. "There may be value in increasing dementia-related clinical resources in the winter and early spring, when symptoms are likely to be most pronounced," suggests the University of Toronto's Andrew Lim. The team estimated that improvements in average thinking skills in the summer and fall were equivalent to almost five years less in age-related declines in thinking ability. This seasonal variance persisted even after factors such as depression, sleep, physical activity, and thyroid status were accounted for. There also were seasonal variations in levels of Alzheimer's-related proteins and genes in cerebrospinal fluid and the brain. "By shedding light on the mechanisms underlying the seasonal improvement in cognition in the summer and early fall, these findings also open the door to new avenues of treatment for Alzheimer's disease," concludes Lim.