Most of us have been told time and again that we aren’t getting enough sleep, but not everyone understands the true significance of sleep for our physical health, memory, cognition — and mental wellness. This year, speakers at “Sleep Unraveled,” Gustavus Adolphus College’s 60th annual Nobel Conference, will focus on the central importance of restful sleep to our overall health.
Phillip Voight, associate professor of communication studies and chair of Nobel 60, said the free-of-charge conference, held at Gustavus’ campus in St. Peter on Oct. 1-2, will bring together “an interdisciplinary panel of experts to explore the centrality of sleep for human health and mental well-being.”
Conference speakers include Marishka Brown, director of the National Center on Sleep Disorders Research; Tricia Hersey, a performance artist, theologian and founder of the Nap Ministry; and Amita Sehgal, professor of neuroscience at the University of Pennsylvania Perelman School of Medicine, among others.
This year’s conference focus is important, Voight said, because American culture increasingly puts the need to be “on” at all times above sleep. This shift puts everyone at greater risk of serious health complications, he said, and conference organizers want audience members to learn what international sleep experts have to say about this issue.
“The conference will also delve into the neurological and psychological processes of sleep, the cultural evolution of sleep practices, and the social justice implications of a twenty-four-hour convenience society that condemns workers to permanent sleep deprivation,” Voight said.
Recently, I spoke to two Nobel Conference presenters, Mary Carskadon, professor of psychiatry and human behavior at Brown University Medical School, and Robert Stickgold, professor of psychiatry at Harvard Medical School, about the negative impact of the exhausting need for constant connectivity on our mental health. Their research highlights ways that people of all ages can listen to the messages their bodies are sending them to help prioritize their sleep and keep themselves healthier. The following interviews have been edited for length and clarity.
MinnPost: Dr. Carskadon, much of your research has focused on the sleep patterns of adolescents. How did that interest start?
Mary Carskadon: When I started grad school, there was a professor on my dissertation committee. His name was Thomas Anders. He was a child psychiatrist who was interested more in younger children and sleep, but he encouraged my work, which at the time included developing a “sleep camp” so we could do a longitudinal sleep study with kids. The youngest [study participants] were about 10 years old when they started. They came to Sleep Camp for about four or five summers. What we found there was very interesting.
MP: Sounds exciting. What did you learn?
MC: I had a naïve hypothesis that, as they aged or matured, kids would need less sleep because it was pretty clear that, across early-to-mid-adolescence, kids were sleeping less. Why wouldn’t we want to show the biology of that? It turned out that my hypothesis was not supported. We discovered that, as they got to early- or mid-adolescence, teens still needed at least the same amount of sleep as they did when they were younger. They just needed that sleep at different times. I became very interested in looking deeper into what was going on with sleep during adolescence.
MinnPost: How did you and your team set out to understand that?
MC: We have a test that we do in the daytime where we measure the speed of falling asleep at various points during the day. We found out that as people were transitioning into mid-adolescence they showed a different pattern when they became sleepy based on this test.
What flipped the script was our finding that teens’ circadian biological clocks moved to a later time, and adolescents could still get plenty of sleep — but only if their sleep schedule moved to a later time, which would include sleeping later into the morning. This presented a problem: In the early-to-mid ‘80s and beyond, middle- and high-school kids started school earlier than the younger kids, as early as 7:30 in the morning. That truncated the amount of downtime that teens had. The way their biological clock works, that meant that teenagers were sleeping less.
MinnPost: Does a lack of sleep have an impact on the mental health of adolescents?
MC: It’s been shown time and time again. We worked with a fairly substantial survey study in New England that showed that adolescents who were sleeping less were reporting more symptoms of depression. There have been a lot of studies since, including one impressive one from data that’s collected in these big nationwide surveys, that showed that the teenagers who were sleeping six or fewer hours a night were engaging in more risk-taking activities like not wearing a helmet or driving recklessly and engaging in self-harm.
The impact of a sleep deficit on high school students is significant: There is also research that shows that the number of teen automobile crashes is higher in school districts that have very early school-start times
MP: Those are significant concerns. What do you see as the most distressing mental health impact of inadequate sleep in teens?
MC: They are all concerning, but self-harm had the biggest impression on the data that was collected. Self-harm is a really scary signal about the mental health impact of not getting enough sleep.
MP: Anyone who’s lived with a teenager knows that they like to sleep late on weekends. Why is that?
MC: What happens on weekends is these youngsters will try to make up for their lost sleep during the week. Following their internal schedule means that, given the opportunity, teens will sleep late, until 10 or 11 or 12. That pattern has a name. It’s called “social jetlag.” It is not unique to teenagers; a lot of grownups who don’t get enough sleep during the weekdays will also oversleep or binge sleep on weekends.
The phenomenon of social jetlag shows that these individuals are forced to sleep on a different schedule than their internal clock wants them to, so on weekends their body moves to a schedule that is more comfortable to them.
MP: Has your research shown that older people need less sleep than children and adolescents?
MC: There is growing evidence that with age we need less sleep than when we did when we were younger, but there’s still too many people even in middle age who are not getting adequate sleep. You see it reflected in many things.
MP: Dr. Stickgold, what do you see as the most significant mental health impact of inadequate sleep?
Robert Stickgold: Depression is bidirectionally related to sleep. A long time ago, in the late ‘90s, I gave a couple of talks at Harvard and MIT. When I spoke with people in student health at Harvard, I asked, “When a student comes in and says, ‘I’ve been depressed lately,’ do you ask them about their sleep?” They said, “There is a question about sleep in the standard questionnaire. We just write down their response.” There was no sense of a connection between depression and loss of sleep. But when I talked to people [in student health] at MIT, they said, “Well, duh. One of the first questions we ask when a student says they are feeling depressed is, ‘How much sleep are you getting?’” They had such different responses.
A lack of sufficient sleep tends to make you depressed. All you need to know to confirm this fact is to have a bed partner. If your bed partner doesn’t get enough sleep at night, when they wake up they are so terrible that you don’t even want to be near them.
MP: It sounds like there’s a clear interconnection there.
RS: Yes. Depression can lead to a loss of sleep. A loss of sleep can lead to depression. You get into a vicious cycle.
MP: Are there other mental health conditions that are impacted by sleep?
RS: When I was on that visit at MIT, one of the nurses there said, “I had a student with bipolar disorder come in today. He was upset. He said that he’d been taking his medication, but he had a paper due and pulled two all-nighters and flipped into mania.” We know that in people with bipolar disorder, a loss of sleep can trigger mania. And when you are in a manic state you get profoundly less sleep than you normally do. Mania is a very strange thing: People love it except when they hate it.
MP: One of the many fascinating aspects of your research is your focus on dreams and their ability to help people process traumatic life events. Can you tell me more about what you’ve learned about sleep, dreams and PTSD?
RS: I’ve actually put out a couple of theoretical papers where I allege that PTSD is in fact a product of disordered sleep-dependent memory processing. With PTSD, if you look at the forms of sleep-dependent memory processing, what we now know from experimental studies is that people with PTSD have to learn to cut off their strong emotional response to memories of the traumatic event that shaped their lives. They have to stop remembering the traumatic event in all of its details. When you experience a traumatic event, the memory is often seared into your mind.
With PTSD, the details don’t go away. They may have recurring, detailed dreams of the traumatic event. It is one of the hallmarks of PTSD. One of the things that has to happen is for the person with PTSD to find a way to let those details go away, to decrease the emotional strength of their response when they remember the event. They have to learn to integrate that traumatic memory into the realm of the other memories in their lives.
MP: And so much of that trauma is replayed in dreams, right?
RS: It turns out when you have PTSD, you remain hyper-aroused when you are sleeping. That hyperarousal is dependent on adrenaline in the brain. Those are contrary to REM sleep. Usually you find a decrease in REM sleep with people with PTSD.
When I talk to my wife, who is a trauma specialist and a psychotherapist, she tells me about the list of all of the things she tries to do with a patient with PTSD over time. Turns out that, under the best conditions, that stuff all happens naturally in your sleep.
MP: So with PTSD, it’s kind of like a person’s brain is getting stuck in a rut of sorts, replaying the same traumatic event over and over?
RS: People with PTSD are like the friend who tells you the story of how they just broke up with this person and the next time you see them they tell you that same story again. That’s because their brain has frozen that moment in a crystalline form that they can’t integrate into their past and future.
In 2021, my colleague Antonio Zadra and I published a book called, “When Brains Dream.” People say it was fun to read, which you don’t usually hear about a scientific book. In the book we come up with a theory for why we dream, which we call the NEXTUP, or Network Exploration to Understand Possibilities, theory.
This theory is that when we dream, our brain identifies matters of concern from our waking life that we are working on currently and trying to figure out what to do or how to understand. The dreaming process helps us to do that. It goes through networks of associated memories to try to find memories that feel related to this waking concern. Ideally these are memories that are more distant and more weakly related to [the area of concern]. The brain is trying to construct narratives out of associated memories and try to see if they get a buzz out of you. If it does, it connects them with your waking concerns.
Andy Steiner
Andy Steiner is a Twin Cities-based writer and editor. Before becoming a full-time freelancer, she worked as senior editor at Utne Reader and editor of the Minnesota Women’s Press. Email her at asteiner@minnpost.com.
