The effect of hardiness on symptoms of insomnia during a naval mission.

BACKGROUND: Sleep is increasingly being recognised as important for the health and well-being of sailors. The aim of the current study is to investigate the relationship between hardiness and reported insomnia-symptoms in a maritime military setting during a 4-month counter piracy naval mission in the Gulf of Aden.

MATERIALS AND METHODS: A sample of 281 officers, sailors, and enlisted personnel were measured on levels of hardiness before the mission. The participants were split into low and high hardiness groups based on the group level mean. Insomnia-symptoms were measured before, midway and at the end of the mission.

RESULTS: The results showed a significant main effect of time and a significant main effect of hardiness. The crew experienced the most insomnia symptoms in the middle of the mission and the high hardy group experienced less insomnia symptoms, in total, during the mission. There was also found a significant interaction effect of time and hardiness. The high hardiness group experienced less insomnia symptoms before and towards the end of the mission.

CONCLUSIONS: The results indicate that high levels of hardiness may be a protective factor between the stressors of a naval mission and symptoms of insomnia.