As parents of young babies will testify, regularly waking in the night can leave you feeling drained.
Now experts say that interrupted sleep can be as physically detrimental as having no sleep at all.
A new study links interrupted sleep patterns and compromised cognitive abilities, shortened attention spans, and negative moods.
‘The sleep of many parents is often disrupted by external sources such as a crying baby demanding care during the night,’ said Professor Sadeh, who led the study, conducted at 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.’
The researchers discovered that interrupted sleep is equivalent to no more than four consecutive hours of sleep.
‘Our study is the first to demonstrate seriously deleterious cognitive and emotional effects,’ said Professor Sadeh.
‘In the process of advising these parents, it struck me that the role of multiple night wakings had never been systematically assessed.
‘Our study shows the impact of only one disrupted night.
‘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.
‘Sleep research has focused in the last 50 years on sleep deprivation, and practically ignored the impact of night-wakings, which is a pervasive phenomenon for people from many walks of life.
Prefessor Sadeh, who directs a sleep clinic, said that the study demonstrated that induced night wakings, in otherwise normal individuals, clearly lead to compromised attention and negative mood.
The study was conducted on student volunteers at TAU’s School of Psychological Sciences.
Their sleep patterns were monitored at home using wristwatch-like devices that detected when they were asleep and when they were awake.
The students slept a normal eight-hour night, then experienced a night in which they were awakened four times by phone calls and told to complete a short computer task before going back to sleep after 10-15 minutes of wakefulness.
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 compromised attention, negative mood, and disrupted sleep — after only one night of frequent interruptions.
The study was published in the journal Sleep Medicine.
