Being woken up regularly during the night can leave parents and on-call workers feeling as sleep deprived as if they had only four hours rest a night
It will come as no surprise to new parents struggling after a night of feeds or doctors on call, but being woken up in the night is as detrimental as getting just four hours of sleep.
Researchers discovered that being pulled from a deep slumber by a crying baby or a frantic emergency call, causes the same confusion, depression and fatigue as being severely sleep-deprived.
It means that even when people get a total of seven hours sleep a night, being forced to wake up for regular 15 minute feeds, or consultations, will leave them feeling like they had just four hours rest.
Researchers at Tel Aviv University’s School of Psychological Sciences warn that it is likely to leave parents feeling bewildered, dejected and exhausted and effect on-call professionals like doctors or fire-fighters, impacting decision making and attention spans.
“The sleep of many parents is often disrupted by external sources such as a crying baby demanding care during the night,” said Professor Avi Sadeh and a team of researchers from Tel Aviv University’s School of Psychological Sciences.
“Doctors on call, who may receive several phone calls a night, also experience disruptions.
“These night wakings could be relatively short – only five to ten minutes – but they disrupt the natural sleep rhythm.
“The impact of such night wakings on an individual’s daytime alertness, mood, and cognitive abilities had never been studied. Our study is the first to demonstrate seriously deleterious cognitive and emotional effects.”
The team studied 61 adults who were monitored at home using wrist-watch like devices which detected when they were asleep and when awake.
The volunteers slept a normal eight-hour night, then experienced a night in which they were awakened four times by phone calls every 90 minutes and not allowed to go back to sleep for 15 minutes.
The students were asked each following morning to complete certain computer tasks to assess alertness and attention, as well as to fill out questionnaires to determine their mood.
The experiment showed a direct link between disrupted sleep and poor attention spans and negative mood after only one night of frequent interruptions.
The volunteers were found to be on average 24 per cent more confused, 29 per cent more depressed and 43 per cent more fatigued.
A second experiment where volunteers were only allowed to sleep for four hours, showed similar results, suggesting regular night disruption has the same impact as only getting half the recommend eight hours of sleep.
“Our study shows the impact of only one disrupted night,” said Prof. Sadeh.
“But we know that these effects accumulate and therefore the functional price new parents-who awaken three to ten times a night for months on end-pay for common infant sleep disturbance is enormous.
“Besides the physical effects of interrupted sleep, parents often develop feelings of anger toward their infants and then feel guilty about these negative feelings.”
