Drugs in space and sleepless in the shuttle

A fascinating study published in today’s Lancet Neurology reports on sleep deprivation in astronauts but also describes the drugs shuttle crew members use to keep themselves awake and help them fall asleep.

The study looked at sleep data from 64 astronauts on 80 space shuttle missions along with 21 astronauts on 13 International Space Station missions, and compared it to their sleep on the ground and in the days before space flight.

Essentially, in-flight astronauts don’t get a great deal of shut-eye, but what’s surprising is the range and extent of drugs they use to manipulate sleep.

Mostly these are the z-drug class of sleep medications (of which the best known is zolpidem, branded name Ambien) but also include benzos, melatonin and an antipsychotic called quetiapine.

Here are the sleep-inducing drugs with my comments in square brackets:

Zolpidem and zolpidem controlled release were the most frequently used drugs on shuttle missions, accounting for 301 (73%) and 49 (12%) of the 413 nights, respectively, when one dose of drug was reported. Zaleplon use was reported on 45 (11%) of 413 nights.

Other sleep-promoting drugs reported by shuttle crew members during the 413 nights included temazepam [sedative anti-anxiety benzodiazepine – similar to Vallium] on 8 (2%) nights, eszopiclone on 2 (<1%) nights, melatonin [hormone that regulates circadian rhythms] on 7 (2%) nights, and quetiapine fumarate [antipsychotic] on 1 (<1%) night.

The paper also notes concerns about the astronauts’ use of zolpidem and similar z-drug medications because they can affect mental sharpness, coordination and can lead to unusual and complex ‘sleep-behaviours’.

Interestingly, it seems astronauts tend to use these drugs in a rather ad-hoc manner and the consequences of this have clearly not been well thought through.

As the Lancet Neurology paper notes:

This consideration is especially important because all crew members on a given mission might be taking a sleep-promoting drug at the same time…. crew members reported taking a second dose of hypnotic drugs—most commonly zolpidem—often only a few hours before awakening. Although crew members are encouraged to try such drugs on the ground at home at least once before their use in flight, such preparations probably do not involve multiple dosing or dosing with two different drugs on the same night.

Furthermore, such tests do not include any measure of objective effectiveness or safety, such as what would happen in the case of abrupt awakening during an in-flight night-time emergency… sleep-related-eating, sleep-walking, and sleep-driving events have been reported with zolpidem use, leading the FDA to require a so-called black-box warning on all hypnotic drugs stating that driving and performance of other tasks might be impaired in the morning after use of such drugs:

“A variety of abnormal thinking and behavior changes have been reported to occur in association with the use of sedative/hypnotics…. Complex behaviors such as ‘sleep-driving’…have been reported. Amnesia, anxiety, and other neuropsychiatric symptoms may occur unpredictably.”

However, use of sleep drugs was reported on more than half the nights before extravehicular activities were undertaken.

Information on stimulant use by astronauts is hidden in the appendix but caffeine was widely used in space, but less than when on the ground – although possibly due to coffee shortages, and modafinil was used occasionally.

Caffeine was widely used throughout all data collection intervals by both shuttle and ISS crewmembers, though supply shortages sometimes led to coffee rationing and reduced consumption aboard ISS. All but eight shuttle mission crewmembers (72/80, 90%) and all but one ISS crewmember (20/21,95%) reported using caffeine at least once during the study…

Given the 3-7 hour half-life of caffeine and the sleep disturbances associated with its use, caffeine may have contributed to or enabled the sleep curtailment observed in this population. However, there is no evidence that caffeine accounts for the reduced sleep duration observed during spaceflight, as caffeine consumption was, if anything, reduced during spaceflight.

The wakefulness-promoting medication, modafinil, was reportedly used on both shuttle (10 reported uses) and ISS missions (2 reported uses). The use of this wakefulness-promoting medication was reported more frequently in post-flight debriefs.

There’s also an interesting snippet that gives the most common reason for sleep disturbance in space:

Nocturnal micturition is common in this age group and was the most reported reason for disruptive sleep both on Earth and inflight

Not stress, not being surrounded by equipment, not a lack of home comforts, but ‘Nocturnal micturition’ or wetting yourself in your sleep.

This is possibly more likely in space due to the fact that bodily cues for a full bladder work less effectively in zero gravity, but one major factor in astronauts wetting themselves was that it a better alternative than waking sleeping colleagues by going to the toilet.

The paper notes that this is why many astronauts wear ‘maximum absorbency garments’ – essentially giant nappies – while they sleep.
 

Link to locked Lancet study on sleep in astronauts.

Hallucinating in the deep waters of consciousness

On Saturday I curated a series of short films about other inner worlds, altered states and the extremes of mental health at London’s Shuffle Festival. I discovered one of the films literally a couple of days before the event, and it completely blew me away.

Narcose is a French documentary about a dive by world champion free diver Guillaume Néry. It documents, in real time, a five minute dive from a single breath and the hallucinations he experiences due to carbon dioxide narcosis.
 

 

Firstly, the film is visually stunning. A masterpiece of composition, light and framing.

Secondly, it’s technically brilliant. The director presumably thought ‘what can we do when we have access to a community of free divers, who can hold their breath under water for minutes at a time?’ It turns out, you can create stunning underwater scenes with a cast of apparently water-dwelling humans.

But most importantly it is a sublime depiction of Néry’s enchanted world where the boundaries between inner and outer perception become entirely porous. It is perhaps the greatest depiction of hallucinations I’ve seen on film.

Darken the room, watch it on as big a screen as possible and immerse yourself.
 

Link to Narcose on Vimeo.

Why bad news dominates the headlines

Why are newspapers and TV broadcasts filled with disaster, corruption and incompetence? It may be because we’re drawn to depressing stories without realising, says psychologist Tom Stafford.

When you read the news, sometimes it can feel like the only things reported are terrible, depressing events. Why does the media concentrate on the bad things in life, rather than the good? And what might this depressing slant say about us, the audience?

It isn’t that these are the only things that happen. Perhaps journalists are drawn to reporting bad news because sudden disaster is more compelling than slow improvements. Or it could be that newsgatherers believe that cynical reports of corrupt politicians or unfortunate events make for simpler stories. But another strong possibility is that we, the readers or viewers, have trained journalists to focus on these things. Many people often say that they would prefer good news: but is that actually true?

To explore this possibility, researchers Marc Trussler and Stuart Soroka, set up an experiment, run at McGill University in Canada. They were dissatisfied with previous research on how people relate to the news – either the studies were uncontrolled (letting people browse news at home, for example, where you can’t even tell who is using the computer), or they were unrealistic (inviting them to select stories in the lab, where every participant knew their choices would be closely watched by the experimenter). So, the team decided to try a new strategy: deception.

 

Trick question

Trussler and Soroka invited participants from their university to come to the lab for “a study of eye tracking”. The volunteers were first asked to select some stories about politics to read from a news website so that a camera could make some baseline eye-tracking measures. It was important, they were told, that they actually read the articles, so the right measurements could be prepared, but it didn’t matter what they read.

After this ‘preparation’ phase, they watched a short video (the main purpose of the experiment as far as the subjects were concerned, but it was in fact just a filler task), and then they answered questions on the kind of political news they would like to read.

The results of the experiment, as well as the stories that were read most, were somewhat depressing. Participants often chose stories with a negative tone – corruption, set-backs, hypocrisy and so on – rather than neutral or positive stories. People who were more interested in current affairs and politics were particularly likely to choose the bad news.

And yet when asked, these people said they preferred good news. On average, they said that the media was too focussed on negative stories.

 

Danger reaction

The researchers present their experiment as solid evidence of a so called “negativity bias“, psychologists’ term for our collective hunger to hear, and remember bad news.

It isn’t just schadenfreude, the theory goes, but that we’ve evolved to react quickly to potential threats. Bad news could be a signal that we need to change what we’re doing to avoid danger.

As you’d expect from this theory, there’s some evidence that people respond quicker to negative words. In lab experiments, flash the word “cancer”, “bomb” or “war” up at someone and they can hit a button in response quicker than if that word is “baby”, “smile” or “fun” (despite these pleasant words being slightly more common). We are also able to recognise negative words faster than positive words, and even tell that a word is going to be unpleasant before we can tell exactly what the word is going to be.

So is our vigilance for threats the only way to explain our predilection for bad news? Perhaps not.

There’s another interpretation that Trussler and Soroka put on their evidence: we pay attention to bad news, because on the whole, we think the world is rosier than it actually is. When it comes to our own lives, most of us believe we’re better than average, and that, like the clichés, we expect things to be all right in the end. This pleasant view of the world makes bad news all the more surprising and salient. It is only against a light background that the dark spots are highlighted.

So our attraction to bad news may be more complex than just journalistic cynicism or a hunger springing from the darkness within.

And that, on another bad news day, gives me a little bit of hope for humanity.