A common theme in the Pittsburgh Dental Sleep Medicine blog is this: sleep (or lack thereof) really can affect all parts of an individual’s complete health. We’ve touched on how sleep and diseases like sleep apnea can tie into anxiety, depression, Alzheimer’s, ADHD – to name a few. The most recent study that caught our eye from Sleep Review Magazine is the connection between sleep apnea, memory loss and depression.

New information suggests that these three concepts may be interrelated.  Australian university RMIT headed up this study. They found that “people with untreated OSA had problems recalling specific details about their lives.”

The doctors in Australia seemed to consider memory loss to be a known variable of depression. Because of the ties between memory loss and depression, ties between sleep apnea and depression, and ties between sleep apnea and memory loss, it seems that all three could be significantly interrelated. Dr. Melinda Jackson began the study based on the tie between memory loss and depression.

Semantic Memory vs. Episodic Memory

“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 biographical memory.”
Semantic memory is a more factual-based part of an individual’s memory, whereas episodic memory is based on an individual’s own experience and can include more broad, emotional and situational memories.  LiveScience has an interesting comparison between the two here: https://www.livescience.com/42920-semantic-memory.html.  Semantic memory seems to be what suffers most in those with sleep apnea and depression.

Study Findings

Comparing a group of healthy adults to a group of adults with untreated OSA, the findings were startling. 52.3% of the OSA group had overgeneral memories – more episodic memory capabilities versus semantic. The healthy group of adults had 18.9% overgeneral memories – showing a large gap in memory-related differences that seem to be closely related to OSA. Unsurprisingly, increased age effected both groups’ semantic memories.

Though this study does not offer concrete evidence, it has definitely encouraged a greater insistence on pursuing the matter further.

We need to look at whether there’s a shared neurobiological mechanism at work – that is, does the dysfunction of that network lead to both depression and memory problems in people with sleep apnea?”

-Dr. Melinda Jackson

Whether you suffer from sleep apnea, depression, or memory loss – all information is relevant and worthy of further exploration as part of your healing journey. At PDSM, we will continue to keep an eye on these studies and report further as more is known.