Group Dynamics and Catecholamines During Long-Duration Confinement in an Isolated Environment

Kraft NO, Lyons TJ, Binder H. Group dynamics and catecholamines during long-duration confinement in an isolated environment. Aviat Space Environ Med 2003; 74:266–72

Introduction: The objectives of this study were to investigate possible relationships between catecholamine excretion and long-duration confinement in an isolated environment. Methods: Stays of long duration were made by Group I (n = 4, all Russian, weeks 1–34), Group II (n = 4, mixed nationality, weeks 3–18), and Group III (n = 4, mixed nationality, weeks 22–38); other groups joined the residents for 1-wk intervals at weeks #13, #19, and #33. Data were collected from Groups I and III. Results: In both Group I and Group III, the daily epinephrine excretion was significantly elevated during and after confinement compared with the pre-isolation baseline (p < 0.05), but remained mostly within normal limits during the experiment. During isolation, epinephrine excretion was significantly higher, compared with other weeks in isolation, during weeks #19 and #27 for Group I, and during week #30 for Group III. In both Group I and Group III, norepinephrine excretion increased significantly during and after isolation (p < 0.05) and was above the normal range. The daily norepinephrine excretion was significantly higher (p < 0.05) in Group I during weeks #12, #13, and #27, and during week #30 for Group III. Discussion: Epinephrine excretion generally remained in the normal range. However, occasional elevations occurred due to psychological stress, which apparently correlate with changes in group dynamics. Norepinephrine excretion was above the normal range and was correlated with social events. These results suggest that to ensure optimum crew performance, entire crews along with their visiting crews should be selected collectively, rather than individually.