Now, good sleep is important – that’s indisputable. But as the issues above make clear, what counts as “good” is really a mixture of myriad different factors. So, in an effort to de-oversimplify the issue, a new study takes a more holistic approach to quantifying sleep – and has found that, when it comes to sleep, you’re not one in a million. You’re one in five.
“Sleep is made up of many dimensions, not just how long we sleep,” wrote the researchers behind the project in a statement this week. “By analyzing more than 700 young adults, we discovered five distinct ‘sleep profiles’ based on reports of sleep duration, presence of disruptions, [and] use of sleep medications.”
“Each profile carried its own distinctive link in health, lifestyle, and cognition,” they reported, “and even showed unique neuroimaging traits using functional MRI.”
So, what do we need to know?
Two big hitters
Everybody likes to feel seen – that’s why personality tests are so popular. So where in this new paradigm do you fall?
Well, our sympathies if you fall into the first group. These are the people who suffer from bad sleep: they report “decreased sleep satisfaction, longer time to fall asleep, greater complaints of sleep disturbances, and daytime impairment,” the study notes, and, whether as a result of that, a cause of it, or a bit of both, they also report problems with their general mental health. For example, they were more likely to suffer from depressive problems, anxiety problems, and neuroticism, and be more stressed, fearful, and angry.
That’s not entirely surprising. “The dominance of mental health markers in most of the profiles is not surprising as sleep is one of the five key domains of human functioning likely to affect mental health,” said Valeria Kebets, Manager of Machine Learning Projects at Concordia University and coauthor of the paper. But what was striking was just how strong these correlations were: the researchers estimated this sleep profile alone explained almost 90 percent of the covariance between sleep and mental health features in healthy adults.
“Overall, poor sleep is not only a risk factor but also a co-morbid condition and transdiagnostic symptom for many mental disorders,” they concluded, noting that “when sleep is disrupted, it […] contributes to the dysregulation of multiple neurobiological mechanisms related to emotional regulation and psychopathology.”
However, having said all that, let’s take a look at the second profile. These people also suffered from symptoms of bad mental health – albeit slightly different ones from the first group: they reported attention problems and low conscientiousness, for example, rather than the more neurotic-type conditions. What really set them apart from the first profile, though, was the fact that they didn’t seem to suffer from poor sleep – they were, in the researchers’ words, “sleep resilient”.
Why that might be, however, is kind of mysterious. It could be that these individuals are just able to sleep well despite their problems – hence the “resilient” moniker – though “the cause of such resilience is unclear,” the researchers write. Perhaps it’s some so-far-unrecognized biological factor that’s protecting them, or something environmental.
Maybe it’s not a real phenomenon at all: “Another possible interpretation is that [this profile] might reflect individuals who may lack insights into their sleep difficulties, particularly relative to other concerns that are more burdensome to them,” the team suggests. “Indeed, some individuals often fail to recognize the full impact of their sleep disturbances and attribute their daytime symptoms to external factors or normalize their tiredness.”
Waking, shaking, and sleep-medicating
So much for the first two profiles – now onto the latter three. And there is good reason for splitting them up like this: profiles three, four, and five were all marked by more specific aspects of sleep, rather than general statements of mental health.
So, the third profile first, and this is one that quite a few of you might recognize: “This profile specifically highlights a subgroup of young adults who appear to manage sleep difficulties with pharmacological solutions,” the study explains.
These people were highly sociable, conscientious, and friendly, and reported fewer problems with things like attention and childhood behavior. They also complained less of problems with daytime functioning or sleep quality, which makes sense since that’s precisely what they’re taking the drugs for.
It’s not all good news for this group, though. Their brainwork “showed increased [resting-state functional connectivity] within the visual and default mode networks, and greater segregation in visual and limbic systems,” the team point out, which, “along with impaired visual memory and emotion recognition performance, may reflect sedation-related reductions in network integration that disrupt perceptual and affective-cognitive processes, despite subjectively intact attention and daytime functioning.”
Finally, the fourth and fifth profiles were both associated with not getting enough sleep – though in quite different ways. “While [profile four] was solely driven by sleep duration (i.e., not sleeping enough – reporting <6>sleep disturbances,” the paper explains.
“That can encompass multiple awakenings, nocturia [peeing too much at night], and breathing issues, as well as pain or temperature imbalance,” it adds.
If you’re wondering how these sleep patterns can affect your mental health and brain architecture, then – well, prepare to not be surprised at all. Profile four sleepers showed “worse accuracy and longer reaction time at multiple cognitive tasks,” the study reports, “tapping into emotional processing, delayed reward discounting, language, fluid intelligence, and social cognition.” They, along with profile five sleepers, were also more aggressive, less agreeable… in other words: they were cranky.
You know – like when you don’t get enough sleep.
A bigger picture
Sleep is always a bit tricky to study – but, despite limitations such as relying mostly on self-reports of behavior (which can be faulty or misrepresented) and having a cross-sectional setup (which can’t be used to infer causal relationships), this new research opens the door to more nuanced and in-depth understandings of how sleep differs between individuals.
That’s important, and not only from a theoretical perspective. “Our study […] highlights the importance of considering the full picture of an individual’s sleep to help clinicians make more accurate assessments and guide treatment,” said Aurore Perrault, a postdoctoral researcher in the Sleep, Cognition and Neuroimaging Lab at Concordia University, Montreal, and first author of the paper.
“Different aspects of sleep are related, but can also be separable domains with specific connections to […] lifestyle, mental and physical health and cognitive performances,” she explained.
“The different sleep profiles […] are reflected not just in health and behavior, but also in the brain’s wiring and activity.”
The study is published in the journal PLOS Biology.
Source Link: There Are Five Different Types Of Bad Sleeper. Which One Are You?
