Changes in Risky Behavior in Long-Term Head-Down Bed Rest and Relation to Psychological Status

INTRODUCTION: The present study aimed to investigate changes in risky behavior in a sample of 36 healthy men during a 90-d head-down bed rest (HDBR) experiment and examined whether psychological factors—general self-efficacy, stress, and recovery—could influence these changes.

METHODS: Subjects completed the Balloon Analog Risk Task (BART) and two psychological scales once during the acclimation period, six times during the HDBR period, and twice during the recovery period. During the HDBR period, subjects were required to maintain a −6° head-down position for most daily activities and only permitted to change positions around the longitudinal axis of their bodies.

RESULTS: The results demonstrated that subjects’ risk-taking behaviors were significantly affected by bed rest, with an increased propensity to engage in risky activities during the head-down stage. In addition, BART scores did not return to baseline when subjects entered the recovery stage. In terms of psychological variables, the results indicated that scores of general self-efficacy and recovery were negatively correlated with BART indicators, while stress levels were positively correlated with risky behaviors. Compared to other psychological variables, the perceived physical stress, including fatigue, somatic complaints, and sleep quality, exhibited the strongest correlations with BART indicators.

DISCUSSION: The findings of this study implied that prolonged exposure to a simulated microgravity environment and confined isolation conditions may have a sustained impact on risk-taking tendencies, with changes in risky behaviors in the head-down state more closely associated with physiological symptoms.

He X, Lei Y, Xu Z, Li K, Nicolas M, Wu R, Li Y. Changes in risky behavior in long-term head-down bed rest and relation to psychological status. Aerosp Med Hum Perform. 2025; 96(4):304–313.