Sleep apnea creates holes in life memories: study

New research has shown that people with sleep apnea have difficulty remembering memories of their lives, making them potentially vulnerable to depression.

Obstructive sleep apnea (OSA) is estimated to be over 936 million people worldwide *, a serious condition that occurs when a person's breathing is interrupted while asleep.

People with OSA suffer from memory problems and higher rates of depression, but it is not clear how these problems are related to the development of the disease.

The new study conducted by RMIT University in Melbourne, Australia, examined the impact of this condition on autobiographical memory and found that people with untreated OSA had difficulty remembering the details of their lives.

Chief investigator, Dr. Melinda Jackson, said research was building on the known links between depression and memory.

"We know that too general autobiographical memories – where people do not remember many details of life events – are badociated with the development of a persistent depression," Jackson said.

"Our study suggests that sleep apnea can impair the brain's ability to code or consolidate certain types of life memories, which prevents people from recalling details from the past.

"The OSA is becoming more common and affects up to 30% of older people and about one in four Australian men over the age of 30.

"Sleep apnea is also a significant risk factor for depression so, if we can better understand the neurobiological mechanisms at work, we will have a chance to improve the mental health of millions of people."

The study compared 44 adults with untreated OSAS to 44 healthy controls, evaluating their memory of different types of autobiographical memories of their childhood, their young age and their recent life.

The results showed that people with OSA had a lot more generic memories – 52.3% versus 18.9% of the control group.

The study also looked at the memory of semantic memory (facts and concepts of your personal story, like the names of your school teachers) and episodic memory (events or episodes, like your first day of high school ).

While people with OSA struggled against semantic memory, their episodic memory was preserved. This is probably related to the fragmentation of their sleep habits, research showing that a good sleep is essential to the consolidation of autobiographical semantic memory.

In both groups, being older was badociated with a higher number of general autobiographical memories, whereas a larger depression was badociated with a more degraded semantic memory.

Dr. Jackson, Principal Investigator of the Vice Chancellor at the Faculty of Biomedical Sciences and Health of RMIT, said the results showed the need for further studies to better understand the role of untreated OSA in the processing of memory.

"The brain tests of people with sleep apnea show a significant loss of gray matter in areas that overlap the autobiographical memory network," she said.

"We need to look at whether there is a neurobiological mechanism common to the work, in other words, does the malfunctioning of this network cause both depression and memory problems in the home." people with sleep apnea? "

Jackson said that the use of CPAP machines to treat OSA had helped to improve some of the cognitive impairments badociated with the disease.

"An important next step will be to determine whether effective sleep apnea treatment can also help counteract some of these memory problems, or even restore lost memories."

The study – conducted with collaborators from the Institute of Respiration and Sleep, the Florey Institute of Neurosciences and Mental Health and the University of Melbourne – is published in Journal of the International Society of Neuropsychology (DOI: 10.1017 / S1355617718001091).

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• Sleep apnea occurs when the muscles of the upper respiratory tract sag during sleep, blocking the airways above the voice box.
• Breathing stops for a period of time (usually between 10 seconds and up to 1 minute) until the brain registers lack of breathing or a drop in oxygen level and send a small call to wake up. The sleeper lifts slightly, opens the upper airways, sniffs and gasps, then goes to sleep almost immediately. This pattern can be repeated hundreds of times a night, causing fragmented sleep.
• About one in four men over the age of 30 has some degree of sleep apnea, which makes it more common than asthma.
• Conservative treatment includes weight loss and alcohol reduction.
• Active treatment includes nasal CPAP, mouthguards or surgical correction of upper airway obstruction.
• Daytime sleepiness can distinguish simple snorers from people with sleep apnea.

(source: BetterHealth Channel)

* Overall prevalence of obstructive sleep apnea in adults: estimate using currently available data (American Journal of Respiratory and Critical Care Medicine, 2018)

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