In Korean culture, co-sleeping of parents and children are quite common, which is different from the Western culture where solitary sleeping of children is preferred. In this study, we evaluate the sleep environment factors that effect on children sleep disorder, and parent's parenting stress and mental health.

Surveys were conducted to 115 participating parents of preschool children sleeping behaviour lecture. Seventy-one completed surveys were analyzed for the study. The mean age of target children was 53 ± 23 months. Parents’ mental health was evaluated by using several forms such as Insomnia Severity Index, Korean-Parenting Stress Index short form, and The Patient Health Questionnaire-9. Children's sleeping environment and quality were assessed by Child Sleep Habit Questionnaire and Sleep environment survey.

Pearson correlation analysis (P < 0.05) was conducted to evaluate the relationship between the sleep disorder of children, and the parent's parenting stress and mental health. Analyzing the data through the partial least square path modeling, co-sharing would have negative effect; bed-sharing could have negative effect on the depressing emotion of parents (P = 0.065). Solitary sleeping of children could have positive effect on parent's mental health (P < 0.01).

Preschool children's sleeping disorder occurs more often in co-sleeping children with parents than solitary sleeping children. Parents’ parenting stress is related to the parent's age and depression, further related to the children sleeping disorder and their sleep environment. Although, it is difficult to generalize the exact cause, evaluation and improvement of children's sleep environment would help to reduce the parent's parenting stress.

The authors have not supplied their declaration of competing interest.

Especially medical students set high academic standard, and try hard to achieve because they are requested to studying medicine perfectly. Multidimensional perfectionism scale (MPS) is used to measure perfectionism in medical student. The purpose of the present study was to investigate the relationships between stress and various factors including perfectionism.

We enrolled 159 medical students from University of Ulsan college of Medicine. We used the Medical Stress scale (MSS), the Multidimensional Perfectionism Scale(MPS), the patient health questionnaire-9(PHQ-9), the academic motivation scale (AMS), the insomnia severity scale(ISS), and The revised neo personality inventory.

To analyze data, we used Pearson's correlation and logistic regression analysis. In the first step- Pearson's correlation analysis, a motivation, PHQ-9, ISI, perfectionism and neuroticism traits of NEO-PI significantly correlated with stress level (P < 0.001). In the second step, logistic regression analysis indicated that students who feel high level of academic stress (MSS score ≥ 28) are also related to a motivation, insomnia, perfectionism and neuroticism traits of NEO-PI (R2 = 0.389, P < 0.05).

Student who tend to be perfect feel more academic stress. The high level of stress related to insomnia and a motivation in medical student. Moreover, personality trait also can influences their psychological stress level.

The authors have not supplied their declaration of competing interest.