Is the sleep initiating process affected by psychological factors?

The aim of this study was to investigate the effects of psychological factors on sleep initiating process. The Y-G personality test (Y-G), Lazarus-type stress coping inventory (SCI), Zung self-rating depression scale, General health questionnaire, and Sleep health questionnaire were administered to 418 subjects (mean age = 21.13 +/- 8.76 years), and the data were analyzed by multiple regression analysis (stepwise variable reduction method). Self-rating depression scale; Co-Em, Pla, Sel scale in SCI; C, N, O, Co scale in Y-G were significantly included in the final model. The results showed that psychological factors, such as depression, emotion-focused coping behaviour, prudent planning to solve problems, low self-control, small changes of feeling, nervousness, subjectiveness, and cooperativeness are associated with difficulty initiating sleep.