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Having Frequent, Terrifying Dreams Could Mean You Have Nightmare Disorder

This week in science: A lot of people don't feel much when they take CBD, the effects of microdosing, and what goes on in the brains of people with nightmare disorder.
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Each week, we read what's going on the world of science and bring three of the wildest findings straight to you. Scroll through for the latest:

This is your brain on nightmares

Nightmare disorder, also called dream anxiety disorder, is exactly what it sounds like: when a person is plagued with frequent distressing dreams that are so upsetting, the negative effects spill into real life. What a…nightmare. But what makes someone prone to this, while another person has consistently blissful dreams?


In a new study in NeuroImage: Clinical , researchers found that people with nightmare disorder have an increased response to sensations in their bodies during REM sleep (the phase of sleep when we dream the most), which might lead to them being susceptible to bad dreams.

Lampros Perogamvros, a psychiatrist and neuroscientist at the University of Geneva, and his colleagues used EEG to measure brain activity in people with nightmare disorder and those without, while they were sleeping and awake. They looked for something called heartbeat-evoked potential, or HEP, which represents the response of the brain to our heartbeat. Perogamvros tells me that it reflects the brain and body interaction, or how much we’re feeling our bodies. When a person is in a state of high emotional arousal or stress, the HEP increases.

It’s been previously hypothesized that nightmares would be paired with intense emotional arousal and an increased amount of sensory awareness, so they decided to measure HEP while people were sleeping to see if this was the case.

They found that people with nightmare disorder did in fact have an increased HEP, and it was measured mostly in the frontal areas of the brain, which are often associated with emotional processing.

They only saw increased HEP during REM sleep, but not during non-REM sleep or when people were awake. Intriguingly, Perogamvros says that they saw increased HEP even when they excluded patients who had a nightmare during the actual study. This leads them to believe that it isn’t the nightmares that cause an increased HEP, but an increased HEP that leads to someone being more prone to nightmares.


“These findings corroborate the notion that nightmares are essentially dreams occurring during REM sleep and suggest that increased emotional arousal during REM sleep, as measured by HEP, is a physiological condition responsible for frequent nightmares,” he says.

A study of more than 20,000 cannabis users found that CBD doesn’t do a whole lot

You may have noticed that CBD, or cannabidiol, is popping up everywhere. At a café near my apartment in Brooklyn, I can get it in my coffee and a baked good, then go to a deli and get a CBD-infused sparkling water.

These days, it seems like CBD is winning in a popularity contest against THC, which is the chemical in weed that actually makes you feel high. But CBD and THC are only two of many compounds in cannabis, “hundreds and maybe thousands of combinations of chemical compounds with potential therapeutic effects,” Jacob M. Vigil, an associate professor at the University of New Mexico, tells me.

As we continue to investigate cannabis’s application for conditions like depression, anxiety, pain, insomnia, and other health concerns, it’s hard to know exactly where any purported benefits are coming from—CBD, THC, or somewhere else. Not only are there all these different compound combinations in weed, but people are consuming cannabis in all shapes and sizes—using dried flowers of the plant, concentrates and even suppositories, Vigil says.

The little research that is out there might not be capturing all the ways people use weed, so in a new study in Scientific Reports, Vigil and his colleagues used an app called ReleafApp to observe nearly 20,000 people’s real-time experience with cannabis and its immediate side effects. The app asks people to record the form of cannabis they’re consuming, its major contents (if it’s higher in THC or CBD), and how their use affected various symptoms from depression to seizure to pain.


From the responses, the researchers found that THC appears to be driving most of the effects that come from weed—both good and bad. CBD? Not so much. “In contrast and to our surprise, CBD generally seemed to have little effect on real-time changes in symptom severity levels,” Vigil tells me. One of the problems in studying CBD is that a lot of CBD products are unregulated, and so it’s unclear how the dosage of CBD that’s actually present.

Vigil says there are some other studies that have shown that CBD potency levels seem to help with certain specific symptoms, like insomnia, and it’s shown to help symptoms of pediatric epilepsy.

But we likely still have a lot to learn about CBD, THC, and how they work at different doses, in combination and in isolation to achieve the best effects—especially if we want to use them clinically for a variety of conditions. You can still buy that CBD latte if you want to—as Vigil says,“patients will always face the risk of purchasing ineffective products, some of which may be falsely marketed or otherwise misrepresented.”

What microdosing does is not the same as what we expect it to do

Whenever I read about people microdosing, some of the side effects seem nearly too good to be true. Incredible attention span and focus! Creative genius unlocked! Ability to meditate for hours! But despite all these stories, usually out of tech hubs like Silicon Valley, there has been very little research on microdosing and what really happens when you take these tiny amounts of psychedelic drugs, despite some preliminary intriguing findings.


Because there are legal restrictions to administering psychedelics, sometimes researchers have to turn to other methods to get larger samples sizes. In PLOS One, Vince Polito, a postdoctoral research fellow at Macquarie University in Australia, and his co-author tracked 98 people who were already microdosing psychedelics like LSD and magic mushrooms, and asked them what their expectations experiences and were.

He says that they did find compelling evidence that microdosing has several effects. “We found marked reductions in depression, stress, and mind wandering. We found an increase in imaginative capacities,” he tells me. “We also found a small increase in the personality trait neuroticism. This sounds negative but what it mainly indicates is that people had increased levels of emotional experiences.”

Interestingly, the effects that people believed were going to happen as a result of microdosing often didn’t actually happen. Polito says that one of the reasons they asked people about their expectations was to see whether microdosing responses might be due to the placebo effect, or wishful thinking (which could be considered one and the same).

“We found that people certainly did have strong expectations about microdosing, and predicted that it would have a positive impact on basically every variable that we asked about,” he tells me. “But, when we compared people’s ratings of their expectations with the actual results from our main study, these did not line up too closely.”


People most expected things like creativity, general well-being, and mindfulness to change, but those effects didn’t happen. Instead, the main changes they saw were decreases in depression, stress, mind-wandering; increases in absorption (as in, getting absorbed in an activity) and neuroticism—effects people did not predict as much. This helps affirm the validity of microdosing, Polito says.

“This suggests that the effects we did see were not primarily driven by expectation,” he says. “if we had found large increases in creativity, it would be quite reasonable to say 'oh well that is probably just because people expected that to happen… This indicates that microdosing was an effect on these variables that was independent of expectation.”

Your weekly health and science reads

The Latest Diet Trend Is Not Dieting. By Amanda Mull in The Atlantic.
There’s a reason intuitive eating is so trendy: it’s counter to all the dieting advice we’ve been bombarded with for decades.

Do Not Disturb: How I Ditched My Phone and Unbroke My Brain. By Kevin Roose in The New York Times.
Usually reading articles about cell phone usage makes me feel judged and cagey. Roose has an empathic take on an often-written about subject, that will leave you not depressed, but motivated to spend a little less time staring at screens.

Have Dark Forces Been Messing With the Cosmos? By Dennis Overbye in The New York Times.
Ummm… universe, u ok? The cosmos is expanding about 9 percent more quickly than it’s supposed to.

The psychiatrist who believed people could tell the future. By Sam Knight in The New Yorker.
A spooky psychology story that left me doubting my skepticism around fortune tellers.

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