ISLAMABAD: Losing sleep in favor of some good holiday fun a few times each year is nothing to worry about, but chronic sleep deprivation can have adverse health effects. Some of us are affected more than others, however, and new research helps us understand why.

 For some of us, it may be harder to perform certain cognitive tasks after a sleepless night.
With 50 to 70 million adults in the United States having a "sleep or wakefulness disorder," the Centers for Disease Control and Prevention (CDC) consider sleep deprivation a "public health concern."

Sleep loss is especially alarming given its status as a significant risk factor for traffic accidents and medical mishaps, as well as posing a danger to one's health.

Insufficient sleep could increase the risk of high blood pressure, diabetes, obesity, and cancer, among others conditions.

Cognitively, sleep deprivation has a wide range of adverse effects. In fact, the CDC report that 23.2 percent of U.S. adults aged 20 and above have trouble concentrating, and another 18.2 percent say that they have trouble remembering things as a result of losing sleep.

However, new research shows that the cognitive effects of sleep loss vary from person to person, and that these differences may be down to our genetic makeup.

Scientists led by Paul Whitney, who is a professor of psychology at Washington State University (WSU) in Pullman, found a genetic variation that explains why some people perform certain cognitive tasks a lot better than others after they have been sleep deprived.

Testing the effects of sleep deprivation
Whitney and colleagues examined the cognitive abilities of 49 healthy adults who were aged 27, on average.

Of these adults, 34 were assigned to a sleep deprivation group, while 15 were assigned to a control group. The former went for a period of 38 hours without sleep, while the controls slept normally.

To test the participants' cognitive abilities, the researchers asked them to complete a task before and after the intervention, using a computer screen and a mouse.

The purpose of the task was to assess flexible attentional control by testing the participants' ability to correctly click the left mouse button when they see a certain letter combination on the screen, and the right mouse button for all the other letter pairs.

Participants were instructed to perform the task as quickly and accurately as possible. Importantly, in the middle of the experiment, they were suddenly asked to switch and click the left mouse button for another letter combination.

Whitney and team also performed genotype analyses on the participants and divided the sleep-deprived group into three subgroups, based on three variants of a gene called DRD2.

The DRD2 gene is a dopaminergic receptor that regulates information processing in a brain area associated with cognitive flexibility.