People with sleep apnea struggle to remember details of memories from their own lives, potentially making them vulnerable to depression, according to new research conducted in Australia.
Estimated to affect more than 936 million people worldwide, obstructive sleep apnea (OSA) is a serious condition that occurs when a person’s breathing is interrupted during sleep. People with OSA are known to suffer memory problems and also have higher rates of depression, but it is not well understood how these issues are connected with the development of the disease.
The new study, led by RMIT University in Melbourne, Australia, examined how the condition affected autobiographical memory and found people with untreated OSA had problems recalling specific details about their lives.
Lead investigator Dr. Melinda Jackson said the research built on the known links between depression and memory.
“We know that overly general autobiographical memories – where people don’t remember many specific details of life events – are associated with the development of persistent depression,” Jackson said. “Our study suggests sleep apnea may impair the brain’s capacity to either encode or consolidate certain types of life memories, which makes it hard for people to recall details from the past.
The study compared 44 adults with untreated OSA to 44 healthy controls, assessing their recall of different types of autobiographical memories from their childhood, early adult life and recent life.
The results showed people with OSA had significantly more general memories – 52.3% compared with 18.9% of the control group.
The study also looked at recall of semantic memory (facts and concepts from your personal history, 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 with semantic memory, their episodic memory was preserved. This is likely related to their fragmented sleeping patterns, as research has shown that good sleep is essential for the consolidation of semantic autobiographical memory.
“An important next step will be to determine whether successful treatment of sleep apnea can also help counter some of these memory issues or even restore the memories that have been lost.”
You Can Learn While You Sleep