Prevalence and risk factors of problematic Internet use: a cross-national comparison of Japanese and Chinese university students.

The aim of the present study was to compare risk factors for problematic Internet use (PIU) among Japanese and Chinese university students. A sample of 267 Japanese and 236 Chinese first year university students responded to questionnaires on the severity of PIU, depression, self-image/image of others, and perceived parental child-rearing styles. The results indicated that Japanese participants were more likely to demonstrate PIU than their Chinese counterparts. Compared to Chinese students, Japanese students reported more negative self-image, lower parental care, greater overcontrol, and higher depression scores. The PIU group had a higher depression score compared to the normal Internet use group. Compared with the non-PIU group, the PIU group consisted of more male and Japanese participants. Further, they tended to have more negative self-images, saw their mothers to be less caring, and perceived their mothers and fathers as more overcontrolling. PIU is strongly associated with depression, negative self-image, and parental relations. Finally, mediation analysis revealed that such national differences in PIU between Japanese and Chinese were clarified in depression and perceived mother's care. This cross-national study indicated that depression and perceived mother's care were both significant risk factors that were associated with the national difference in PIU between Japanese and Chinese participants.

Presenteeism in college students: reliability and validity of the Presenteeism Scale for Students.

OBJECTIVE: Presenteeism is the impaired work performance due to health problems. We aimed to develop a Presenteeism Scale for Students (PSS), and to reveal the existence of presenteeism among students. METHODS: Students (n = 5,701) in 4 national universities in Japan were recruited via the school-based health examination. Moreover, 122 students participated in a 2-week interval test-retest to examine the reliability and criterion-related validity of the PSS. RESULTS: Of the students, 59.2% indicated some health problems. Allergy was most prevalent health problems, affecting 35.7% of the whole students. Students with emotional problems had higher degree of presenteeism than those with the other problems. The Cronbach's α of the work impairment score of the PSS was 0.90. The Spearman's coefficient for the test-retest score was 0.80 (P < 0.001). Regarding criterion-related validity, Spearman's coefficient between the work impairment score of the PSS and summary score of the SF-36 was -0.60 (P < 0.001). CONCLUSIONS: These findings suggest that the PSS can be expected to be useful for assessment of students with presenteeism. Furthermore, we found that the majority of students have some health problems, and proposed that the issue of presenteeism on campus should be addressed.

Depression and possible cancer risk due to oxidative DNA damage.

The potential link between depression and cancer is an important unsolved question. To clarify this, we compared a cancer-related oxidative DNA damage, 8-hydroxydeoxyguanosine (8-OH-dG), in peripheral leukocytes between 30 patients with depression and 60 age- and gender-matched healthy controls, and examined the 8-OH-dG-related factors. The degree of depression was assessed by the scores of the Center for Epidemiologic Studies Depression scale (CES-D) and the Profile of Mood States (POMS). The patients showed significantly higher 8-OH-dG levels than the controls. There was a significant positive correlation between the CES-D scores and the 8-OH-dG levels in depressive, particularly female, patients. Multiple regression analysis indicated that whether the subjects were patients or controls was a significant predictor of the 8-OH-dG levels in male and total subjects, as was the CES-D score or the Depression-Rejection score of the POMS in female subjects. This study suggests that clinical depression is a risk factor for cancer initiation in view of oxidative DNA damage.

Psychological mediation of a type of oxidative DNA damage, 8-hydroxydeoxyguanosine, in peripheral blood leukocytes of non-smoking and non-drinking workers.

BACKGROUND: The present study investigates whether the formation of 8-hydroxydeoxyguanosine (8-OH-dG), a known oxidative DNA damage relevant to carcinogenicity, can be associated with psychological factors, in order to clarify the possible stress-cancer linkage from a genetic viewpoint. METHODS: We performed a cross-sectional study in which we examined the relationships of the levels of 8-OH-dG in peripheral blood leukocytes to various psychological factors, including the Profile of Mood States (POMS) and the Center for Epidemiologic Studies Depression Scale (CES-D) in 38 non-smoking and non-drinking workers (19 males and 19 females). RESULTS: The levels of 8-OH-dG in male subjects were negatively correlated with the Tension-Anxiety scores of the POMS. In contrast, the levels of 8-OH-dG in female subjects were positively correlated with the Depression-Rejection scores of the POMS and the CES-D scores, and negatively associated with the Vigor scores of the POMS, respectively. Male subjects who had self-blame coping strategy displayed significantly high levels of 8-OH-dG. Moreover, the worse the subjective closeness to parents in childhood, the higher the levels of 8-OH-dG became in male subjects. The levels of 8-OH-dG increased reliably in subjects who had experienced the loss of a close family member within 3 years, when compared with non-bereaved subjects. CONCLUSIONS: Psychological distress may be associated with cancer risk, although sex difference influences them. Inadequate coping styles, possibly resulting from a poor interpersonal relationship with parents since childhood, and experience of a relatively recent loss of a close family member also appear to influence the pathogenesis of cancer.