Workplace Bullying could Play Important Roles in the Relationships between Job Strain and Symptoms of Depression and Sleep Disturbance: Jiro Takaki, et al. Department of Public Health, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical SciencesObjective: The purpose of this study was to assess whether workplace bullying mediates between job strain, evaluated by the job demand–control model, and symptoms of depression and sleep disturbance.Methods: The subjects in this cross‐sectional study were recruited from all the workers (N=2,634) at 50 organizations in Japan. Due to missing data, the numbers of subjects included in the analyses varied from 1,646 to 2,062 (response rates varied from 62.5% to 78.2%). Job strain and workplace social support, workplace bullying, depression, and sleep disturbance were assessed using the Japanese versions of the Job Content Questionnaire, the Negative Acts Questionnaire, the Center for Epidemiologic Studies Depression Scale, and the Pittsburgh Sleep Quality Index, respectively. Mediation analysis followed the approach outlined by Baron and Kenny. We quantitatively estimated the mediation effects and tested their significance after adjustment for various combinations of demographic variables and workplace social support.Results: Total effects of job strain index on depression or sleep disturbance were all positive and significant (p<0.05) in both genders. Mediation effects of workplace bullying were also all positive and significant (p<0.05) in both genders. Even after adjustment for workplace social support, the mediation effects were decreased, especially in women, but remained significant (p<0.05).Conclusions: Workplace bullying seems to play important roles in the relationships of job strain with depression or sleep disturbance in both genders.

Evaluation of an Internet‐Based Self‐Help Program for Better Quality of Sleep among Japanese Workers: A Randomized Controlled Trial: Etsuji Suzuki, et al. Department of Epidemiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences—The effectiveness of Internet‐based self‐help programs for insomnia is still unclear. A randomized controlled trial was conducted to evaluate the effect of an Internet‐based self‐help program for better quality of sleep among adult workers. Forty‐three volunteers were recruited and randomly assigned to either an intervention group (n=21) or a waiting‐list group (n=22). The intervention group participated in a two‐week Internet‐based program, including selecting and daily practicing sleep‐related target behaviors and monitoring those behaviors along with sleep quality. At the same time, each participant received automatically generated, personalized messages and reports both daily and weekly. A total of 12 intervention group participants and 18 waiting‐list group participants completed questionnaires at baseline, post‐intervention, and at a 3‐wk follow‐up. Subjective sleep quality was measured by a self‐reported questionnaire developed for this study. The sleep quality score increased in the intervention group at post‐intervention, with a significant interaction effect [F(1,28)=5.19, p=0.031]. Sleep‐related behaviors also greatly increased in the intervention group at post‐intervention, with a significant interaction effect [F(1,28)=7.14, p=0.012]. Sleep‐onset latency reduced in the intervention group at follow‐up, with a marginally significant effect [F(1,28)=3.52, p=0.071]. The Internet‐based self‐help program improves subjective sleep quality and sleep‐onset latency among adult workers.

The present study was performed to investigate the associations between eye-blink behaviors and various other factors in primates. We video-recorded 141 individuals across 71 primate species and analyzed the blink rate, blink duration, and “isolated” blink ratio (i.e., blinks without eye or head movement) in relation to activity rhythms, habitat types, group size, and body size factors. The results showed close relationships between three types of eye-blink measures and body size factors. All of these measures increased as a function of body weight. In addition, diurnal primates showed more blinks than nocturnal species even after controlling for body size factors. The most important findings were the relationships between eye-blink behaviors and social factors, e.g., group size. Among diurnal primates, only the blink rate was significantly correlated even after controlling for body size factors. The blink rate increased as the group size increased. Enlargement of the neocortex is strongly correlated with group size in primate species and considered strong evidence for the social brain hypothesis. Our results suggest that spontaneous eye-blinks have acquired a role in social communication, similar to grooming, to adapt to complex social living during primate evolution.

This single-blind randomized study investigated the effectiveness of lavender aroma on quality of sleep in healthy Japanese students. The data of seven participants (2 men, 5 women) in the intervention group and eight participants (3 men, 5 women) in the control group were analyzed ( M age = 19.0 yr., SD = 0.9). The total procedure comprised 3 days for pre-intervention assessment, 5 days for the intervention, and 3 days for post-intervention assessment. Lavender exposure was compared with the absence of lavender (control). Information regarding the relaxing effect of aromas was provided to examine expectancy effects. Results showed that lavender aroma improved sleepiness at awakening after the intervention. Sex differences and daily variation in quality of sleep during the intervention period were not observed. The findings suggest that nighttime exposure to lavender aroma relieves sleepiness at awakening.

Japan's largest platform for academic e-journals: J-STAGE is a full text database for reviewed academic papers published by Japanese societies