March 28, 2017

Human Mars Expeditions: Psychiatric Emergency Could be a Significant Danger

by David Warmflash

At center stage in any type of space colony is the issue of the human mind. Who is most likely to remain mentally healthy and for how long and what stressors, or series of events, can make somebody break down, becoming depressed or psychotic?

It’s easy enough for this to happen on Earth. Part of this is due to environment: in the Northern Hemisphere, during the Winter Solstice, the days grow shorter. This leads the pineal gland in the center of the brain to secrete more melatonin during what should be waking hours. That’s the hormone that makes you sleepy at night and it’s pretty good for you; evidence is accumulating that it helps prevent several types of cancer. Thus, people who work night shifts for many months have an increased cancer risk, whereas blind women actually have a lower than normal risk of breast cancer.

Winter solstice
Earth at the winter solstice, when the Sun’s rays hit the northern hemisphere at an angle. Source: NOAA

There’s a flipside, however, in that messing with the body’s circadian rhythm, the day-night cycle, leads to what psychiatrists called seasonal affective disorder (SAD), known commonly as the winter blues. It’s quite common where I live in the Pacific Northwest and can be treated with light therapy, but things get complicated because some people feel isolated and lonely, specifically because of the holidays. Weirdly, the suicide rate does not go up at this darkest, coldest time of the year, but instead a few months later when spring begins.

Nonetheless, mood disorders are clearly influenced by disruptions in the light-dark cycle, particularly when the disruptions involve a lack of light. Consequently, depression has been noted in people who “winter over” in science bases in Antarctica. Along with submarines, Antarctic bases and outposts in Northern Canada and Greenland are ‘Mars analog environments’. This is because conditions are similar to how things will be in a Mars base, or for that matter a base on the Moon. You are with a small group of people that is both isolated AND confined to limited space. On a submarine hiding under the North Pole, you cannot go outside. In Antarctica, it’s a little better; you can put on snow gear and go outside, which they do for science studies. But is gets dangerous during the wintering over months when the place is in perpetual night.

Mars simulation
Simulation of Mars surface science operations in a large dune field during an extra-vehicular activity from a pressurized rover equipped with rear suit ports. Source: NASA Haughton-Mars Project 2011/Mojave Field Test / Kira Lorber

During an Antarctic expedition back in 1913, for instance, Australian radio operator Sidney Jeffries developed a psychotic disorder. Notably, he displayed paranoid beliefs, declaring that all of this fellow explorers were plotting to murder him. The commander of the expedition, Douglas Mawson, quickly recognized the problem and relieved Jeffries of his duties and happened more than a century ago, but the case illustrates the danger, as do many other examples. There have been cases of depression and psychosis on submarines, and other psychiatric developments in Antarctica, plus anxiety, depression, and adjustment disorders have been reported in astronauts visiting the International Space Station (ISS).

In modern submarines and polar bases, crews and commanders are aware psychiatric conditions can show themselves, so they tend to be vigilant. But they stakes will be even higher during an expedition to any location across space where contact with mission controllers and experts on Earth -including mental health professionalsРand with family members is limited. In Antarctica, the largest base, McMurdo Station tends to have 1,000 people or so during the summer, so the isolation factor is reduced. In polar stations and on the ISS, crew members can communicate with family members in real-time including through video conferencing.

McMurdo Station
NSF’s McMurdo Station, Antarctica in a 2016 photograph. Credit: Mike Lucibella, NSF

If we imagine a lunar base, things will be almost as good. The delay time for a signal to travel between Earth and the Moon is just 1.3 seconds, so you can carry on a conversation with just a slight delay after saying something. Between Earth and Mars, though, the one-way delay can be anywhere from 3-21 minutes, depending on how the planets are aligned. Thus, Mars astronauts will not be able to have conversations with people on Earth. Instead, they can send and receive emails and video messages.

In a real-life isolated environment, like a Mars base, the group dynamics can be hugely important. When things go wrong, cliques can form and people can blame one another for perceived failures of judgment. Something like this happened on Earth with occupants of Biosphere 2.

Biosphere 2
Two missions, between 1991 and 1994, sealed Biospherians inside the glass enclosure to measure survivability. Source: Carol M. Highsmith’s America, Library of Congress, Prints and Photographs Division

This was an enclosed system in the desert of Arizona in the 1990s that was designed to have its own environment, completely separate from the outside. That’s what would be happening on a lunar or Mars colony. Air would be cycled between humans and other animals, plants, and microorganisms, just like on Earth. But things went terribly wrong in Arizona. The concrete was not covered properly, so it started absorbing oxygen. It thus became necessary to inject oxygen from the outside, but this would not be an option on Mars. Perhaps even worse, the team of eight biospherites split up into two cliques. In the end, though, no one died in Biosphere 2. But it does raise important concerns for how we must account for our humanity, with all of its quirks and shortcomings, when exploring the universe.

David Warmflash

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David is an astrobiologist and science writer. He received his M.D. from Tel Aviv University Sackler School of Medicine, and has done post doctoral work at Brandeis University, the University of Pennsylvania, and the Johnson Space Center, where he was part of the NASA's first cohort of astrobiology training fellows. He has been involved in science outreach for more than a decade and since 2002 has collaborated with The Planetary Society on studying the effects of the space environment on small organisms.