Effect of depression on sleep quality in high-altitude recruits during new training: longitudinal moderation of negative cognitive processing bias

Abstract

Objective To explore the change trend and pattern of sleep quality in time dimension in high-altitude recruits during new training, and the longitudinal moderation of negative cognitive processing bias in the process of depression affecting sleep quality. Methods A self-designed demographic data questionnaire, Pittsburgh Sleep Quality Index (PQSI), Negative Cognitive Processing Bias Questionnaire and Self-Rating Depression Scale were used to survey 952 cluster-sampled military recruits during training period who served in high-altitude regions along the Qinghai-Tibet Supply Line. Group assessment was performed in 1, 2 and 3 months after new training. The score for depression at the first month and the score of negative cognitive processing bias at the second month were collected and used to predict the sleep quality at the end of the 3 months of new training. Results The military recruits had a mean score of PSQI of 4.45± 2.44, 4.01±2.15 and 4.45±2.54, respectively in the 3 time points, significantly higher than the national norms for Chinese (P < 0.01). Their sleep quality showed a trend of improving first and then decreasing with the extension of training time (P < 0.01). Nationality, age and educational level significantly affected the sleep quality (P < 0.05). The total PSQI score was positively correlated with educational level, depressed mood, negative cognitive processing bias and its dimensions among these individuals (r=0.131~0.330, P < 0.01). Regulatory effect analysis showed that negative memory bias could modulate the relationship between depression and sleep quality (t=2.498, P < 0.05), and explained 15.7% of the variance rate of sleep quality. Conclusion The recruits serving in high-altitude regions have a severe sleep quality. Nationality, age, educational level, depression and negative cognitive processing bias are important factors affecting the sleep quality in them during new training. Negative memory bias has a significant longitudinal moderate effect between depression and sleep quality and is a risk factor of depression affecting sleep quality, in long-term risk effectiveness.

Keywords

• high altitude
• military recruits
• sleep quality
• depression
• negative cognitive processing bias
• longitudinal moderation