Night Shifts at Work Not Associated with Mental Decline

Late night work shifts are not directly associated with mental decline, according to a study published in the American Journal of Epidemiology.

In a large study, women classified as middle-aged and who worked night shifts didn't suffer any long-term impairment in their thinking skills contrary to common misconception that sleep disruptions could speed-up brain aging. "While we had a good rationale for thinking this association might exist, it simply did not in this dataset," Dr. Elizabeth E. Devore, lead author of the study from the Channing Division of Network Medicine of Brigham and Women's Hospital in Boston said.

The researchers involved in the study found that midlife would be a critical period for influencing early changes in the brain related to memory loss and cognitive decline later on in life, Devore told Reuters Health. Devore and her colleagues used current reports about women's shift habits as they were in 1988, when most of the participants were between the ages of 58 and 68, before they conducted a series of memory and cognitive tests in 1995 and 2001, when the same participants reached the age of 70 and beyond. They checked whether or not mental declines became evident.

According to the results of the study as reported on Medical Daily, there were no significant declines observed after six different cognitive tests were administered every two years, for a total of three points of data collection for each of the subjects. "There is still plenty to be concerned about regarding shift work," Jeanne M. Geiger-Brown, of the University of Maryland School of Nursing, told Reuters Health. "The problem with shift rotation is that the period between two successive shifts can be shorter than the equivalent number of hours on a day off between the same shift."