Structured Review: Psychosocial Stress During Long-Term Stays in Space

Abstract

Over the past few years, the number of Japanese astronauts recruited for a long-term stay in the International Space Station (ISS) has increased. Being on a prolonged mission with the same people, in the same room, should impose psychosocial stress on the astronauts, possibly causing feelings of “psychological suffocation”. Several confinement studies have been conducted to simulate the conditions of the ISS, the Mir space station, and potential habitats on Mars, and to survey psychological interpersonal communication between the crew in a confined environment, including the Isolation Study for European Manned Space Infrastructure, Experimental Campaign for the European Manned Space Infrastructure, Simulation of Flight of International Crew on Space Station, Human Behavior in Extended Spaceflight, Mars-500, and Hawaii Space Exploration Analog and Simulation. Here, the findings from these studies were integrated into a structured review according to an evidence-based set of items for reporting in systematic reviews and meta-analyses. The results indicated that metaanalyses would not always be appropriate because it is difficult to design a research protocol with a high level of evidence in this field. Therefore, future research in this field should be focused on the following three points: 1) developing more accurate parameters for monitoring stress levels in long-term confinement environments; 2) analyzing stress levels in such situations with higher precision; and 3) accumulating and assembling existing and future data from long-term confinement environments.