Mental health, physical symptoms and biomarkers of stress during prolonged exposure to Antarctica's extreme environment

The Antarctic environment is characterized by many of the same extreme stressors as long-duration space flight (LDSE), thereby providing a useful earth-based analog for examining changes in and predictors of mental health over time. At coastal (n = 88) and inland (n = 22) Antarctic stations we tracked mental health symptoms across a nine-month period including winter-over using the Mental Health Checklist (MHCL [1]). Our monthly assessment battery also examined changes in physical complaints, biomarkers of stress, and the use of different emotion regulation strategies. MHCL positive adaptation scores showed linear decreases whereas MHCL poor self-regulation scores and severity of physical symptoms increased across the study period. During-mission use of emotion regulation strategies and dehydroepiandrosterone (DHEA) levels predicted end-of-study MHCL scores, whereas trait-based psychological measures collected at the start of the mission showed little predictive utility. Results suggest that interventions and counter measures aimed at enhancing positive affect/emotion during prolonged exposure to extreme environments may be useful in reducing psychological risk. •Continuous linear decreases in positive emotions were observed at two Antarctic stations.•Changes in negative emotions were variable and predicted by physical complaints.•Greater suppression of emotional responses predicted less positive emotion across mission.•Monthly cortisol levels were lower at the South Pole compared to McMurdo station.•Evidence for a ‘third-quarter effect’ reported in some studies was not found.