Kotaro Imamura

Effects of an Internet-based cognitive behavioral therapy (iCBT) program in Manga format on improving subthreshold depressive symptoms among healthy workers: a randomized controlled trial.

Objective The purpose of this study was to develop a new Internet-based computerized cognitive behavior therapy (iCBT) program in Manga format, the Japanese cartoon, for workers and to examine the effects of the iCBT program on improving subthreshold depression using a randomized controlled trial (RCT) design among workers employed in private companies in Japan. Method All workers in a company (n = 290) and all workers in three departments (n = 1,500) at the headquarters of another large company were recruited by an invitation e-mail. Participants who fulfilled the inclusion criteria were randomly allocated to intervention or control groups (N = 381 for each group). A six-week, six-lesson iCBT program using Manga (Japanese comic) story was developed. The program included several CBT skills: self-monitoring, cognitive restructuring, assertiveness, problem solving, and relaxation. The intervention group studied the iCBT program at a frequency of one lesson per week. Depression (Beck Depression Inventory II; BDI-II) was assessed as a primary outcome at baseline, and three- and six-month follow-ups for both intervention and control groups were performed. Results The iCBT program showed a significant intervention effect on BDI-II (t = −1.99, p<0.05) with small effect sizes (Cohens d: −0.16, 95% Confidence Interval: −0.32 to 0.00, at six-month follow-up). Conclusions The present study first demonstrated that a computerized cognitive behavior therapy delivered via the Internet was effective in improving depression in the general working population. It seems critical to improve program involvement of participants in order to enhance the effect size of an iCBT program. Trial Registration UMIN Clinical Trials Registry UMIN000006210

Working hours and the onset of depressive disorder: a systematic review and meta-analysis

This systematic review and meta-analysis aimed to examine whether working beyond the standard working hours was associated with a greater risk of depressive disorder among workers included in published prospective studies. This manuscript was prepared according to the PRISMA guideline checklist. A database search was conducted using MEDLINE (PubMed), PsycINFO, and PsycARTICLES using a relevant set of keywords. The eligibility criteria were as follows: (1) participants were adult workers; (2) exposure was defined as overtime work; (3) outcome were depressive disorders clinically diagnosed or assessed by a structured interview and (4) the study design was prospective or cohort. 7 studies were identified in the systematic review and meta-analysis. Overtime work was associated with a small, non-significant, elevated risk of depressive disorder (pooled relative risk=1.075; 95% CI 0.834 to 1.387; p=0.575) in a random effects model. The association tended to be greater for women. The risk of working 50 or more hours per week was slightly but not significantly increased (pooled relative risk=1.241; 95% CI 0.880 to 1.750; p=0.218). The effect of overtime work on depressive disorder remains inconclusive and may be small if not negligible. Sex differences and the effect of longer working hours on depressive disorder should be addressed in the future. Trial registration number Prospero CRD42015020003; Results.

Effects of an internet-based cognitive behavioral therapy intervention on improving work engagement and other work-related outcomes: an analysis of secondary outcomes of a randomized controlled trial.

Objective: This study reported a randomized controlled trial of the effectiveness of an Internet-based cognitive behavioral therapy (iCBT) program on work engagement and secondary work-related outcomes. Methods: Participants who fulfilled the inclusion criteria were randomly allocated to an intervention or a control group (N = 381 for each). A 6-week, 6-lesson iCBT program using a Manga (Japanese comic) story was provided only to the intervention group. Work engagement was assessed at baseline and at 3- and 6-month follow-ups for both groups. Results: The iCBT program showed a significant intervention effect on work engagement (P = 0.04) with small effect sizes (Cohens d = 0.16 at 6-month follow-up). Conclusions: The study showed computerized cognitive behavior therapy delivered via the Internet to be effective (with a small effect size) in increasing work engagement in the general working population. Trial Registration: UMIN Clinical Trials Registry (UMIN-CTR) UMIN000006210.

Work Engagement as a Predictor of Onset of Major Depressive Episode (MDE) among Workers, Independent of Psychological Distress: A 3-Year Prospective Cohort Study.

Objective This study investigated work engagement as a baseline predictor of onset of major depressive episode (MDE). Methods The study used a prospective cohort design, conforming to the STROBE checklist. Participants were recruited from the employee population of a private think tank company (N = 4,270), and 1,058 (24.8%) of them completed a baseline survey, of whom 929 were included in this study. Work engagement and psychological distress at baseline were assessed as predictor variables. MDE was measured at baseline and at each of the follow-ups as the outcome, using the web-based, self-administered version of the Japanese WHO-CIDI 3.0 depression section based upon DSM-IV-TR/DSM-5 criteria. Cox discrete-time hazards analyses were conducted to estimate hazard ratios (95% confidence intervals CIs). Results Follow-up rates of participants (N = 929) were 78.4%, 67.2%, and 51.6% at 1-, 2-, and 3-year follow-ups, respectively. The association between work engagement at baseline and the onset of MDE was U-shaped. Compared with a group with low work engagement scores, groups with the middle and high scores showed significantly (HR = 0.19, 95% CI = 0.05 to 0.64; p = 0.007) and marginally significantly (HR = 0.48, 95% CI = 0.20 to 1.15, p = 0.099) lower risks of MDE, respectively, over the follow-ups, after adjusting for covariates. The pattern remained the same after additionally adjusting for psychological distress. Conclusions The present study first demonstrated work engagement as an important predictor of the onset of MDE diagnosed according to an internationally standard diagnostic criteria of mental disorders.

Pokémon GO and psychological distress, physical complaints, and work performance among adult workers: a retrospective cohort study

The effects of Pokémon GO, a new mobile game application which utilizes augmented reality, on risky behavior and health have already been discussed in anecdotal evidence. However, there have been no studies about its effects on mental health. This study investigated the relationships between Pokémon GO and psychological distress from an existing workers’ cohort in Japan. Online surveys were conducted to 3,915 full-time workers, at baseline (Nov 26, 2015–Feb 18, 2016) and at follow-up (Dec 1–4, 2016), using a self-report questionnaire. Pokémon GO players were defined as participants who had played Pokémon GO for one month or longer. Psychological distress was measured using validated scales. Of the completers, 246 (9.7%) had continued to play Pokémon GO. They were significantly younger than non-players. From the results of the general linear modeling, improvement in psychological distress was significantly greater among Pokémon GO players than among non-players (p = 0.025). Cohen’s d for the difference in psychological distress was −0.20 (95% CI, −0.33, −0.07). Pokémon GO may be effective for improving psychological distress among workers. Although its effect size is small, the game could have positive effects on the mental health of the adult working population.

Workplace social capital and the onset of major depressive episode among workers in Japan: a 3-year prospective cohort study

Background This study examined the prospective association of workplace social capital (WSC) with major depressive episode (MDE) among Japanese employees. Methods A 3-year prospective cohort study was conducted among 1058 employees from a private think-tank company who participated in a baseline survey; after excluding those with MDE in the past 12 months, 929 were followed up. WSC at baseline was measured using a 3-item scale. MDE was assessed at baseline and at follow-up every year, by using a web-based, self-administered version of the WHO Composite International Diagnostic Interview (WHO-CIDI) 3.0 depression section, based on the Diagnostic and Statistical Manual of Mental Disorders Fourth Edition: Text Revision (DSM-IV-TR)/DSM-5 criteria. Cox discrete-time hazards analyses were used to estimate HRs and 95% CIs, adjusting for covariates. Results A group with middle-level WSC scores had the lowest risk of MDE after being fully adjusted (HR 0.34, 95% CI 0.14 to 0.84, p=0.02). The relationship between WSC and MDE was U-shaped, although a non-linear model fit better than a linear model, with only marginally statistical significance (p=0.06). Dichotomised and continuous variables of WSC scores were significantly and negatively associated with MDE (p=0.03 and p<0.01, respectively). Conclusions The current study replicated a previous finding from Finland that WSC was a protective factor of the onset of MDE in Japan. The slightly U-shaped relationship, that is, the group with high WSC having a small elevated risk of MDE, may reflect a dark side of WSC in a country with collectivity-oriented and hierarchy-oriented culture, such as Japan.

Work-related psychosocial factors and onset of metabolic syndrome among workers: a systematic review and meta-analysis protocol

Introduction Metabolic syndrome is an important public health target because of its high prevalence worldwide. Work-related psychosocial factors have been identified as determinants of metabolic syndrome components. However, there have been no systematic reviews or meta-analyses conducted to evaluate the relationship between work-related psychosocial factors and metabolic syndrome as an aggregated cluster. The aim of this study is to examine this association from published prospective studies. Methods and analysis The systematic review and meta-analysis will be conducted using published studies that will be identified from electronic databases (ie, PubMed, EMBASE, PsycINFO, PsycARTICLES and Japan Medical Abstracts Society). Studies that (1) examined the association between work-related psychosocial factors and the onset of metabolic syndrome, (2) had a longitudinal or prospective cohort design, (3) were conducted among workers, (4) provided sufficient data for calculating ORs or relative risk with a 95% CI, (5) were published as original articles written in English or Japanese, and (6) having been published until the end of 2016 will be included. Study selection, data collection, quality assessment and statistical syntheses will be conducted based on discussions among investigators. Ethics and dissemination Ethics approval was not required for this study because it was based on published studies. The results and findings of this study will be submitted and published in a scientific peer-reviewed journal. The findings from this study could be useful for assessing metabolic syndrome risk factors in the workplace, and determining approaches for prevention of metabolic syndrome in the future. Trial registration number PROSPERO CRD42016039096 (http://www.crd.york.ac.uk/PROSPERO_REBRANDING/display_record.asp?ID=CRD42016039096)

The effect of a behavioral activation program on improving mental and physical health complaints associated with radiation stress among mothers in Fukushima: a randomized controlled trial

BackgroundMothers living with small children in Fukushima prefecture may experience radiation anxiety and related symptoms after the Fukushima Dai’ich Nuclear Power Plant Accident. A behavioral activation (BA) program was developed to improve their psychosomatic symptoms. The purpose of this randomized controlled trial was to examine the effectiveness of a BA program for improving psychological distress and physical symptoms among mothers with preschool children in Fukushima-prefecture 3 years after the Fukushima Daiichi Nuclear Power Plant accident.MethodsParticipants were recruited from mothers living with a preschool child(ren) in Fukushima city and surrounding areas though a newspaper advertisement, posters, and flyers. Participants allocated to the intervention group received a newly developed group-based BA program, which consisted of two 90- min lessons with a 1-week interval. Psychological distress and physical symptoms as a primary outcome, and radiation anxiety and positive well-being (liveliness and life satisfaction) as a secondary outcome, were measured at baseline, 1- and 3-month follow-ups.ResultsParticipants were randomly allocated to either an intervention or a control group (18 and 19, respectively). The BA program showed a marginally significant intervention effect on psychological distress (p = 0.051) and physical symptoms (p = 0.07) at 1-month follow-up, while the effect became smaller at 3-month follow-up. The effect sizes at 1-month were medium to large (-0.72 and -0.56, respectively). There was a significant intervention effect on increasing liveliness at 3-month follow-up (p = 0.02); and there were marginally significant effects on life satisfaction at 1- and 3-month follow-ups (both p = 0.09).ConclusionsThis BA program may be effective for improving psychological distress, physical symptoms, and well-being, at least for a short duration, among mothers with preschool children after the nuclear power plant accident in Fukushima, while a further large-scale study is needed.Trial registrationThe UMIN Clinical Trials Registry (UMIN-CTR; ID = UMIN000014081). Registered 27 May 2014.

Development of screening inventories for bipolar disorder at workplace: A diagnostic accuracy study

BACKGROUND This study aimed to develop a new instrument for bipolar disorder screening, the Workplace Bipolar Inventory (WBI), and examine its efficiency as compared with Mood Disorder Questionnaire (MDQ) and Bipolar Spectrum Diagnostic Scale (BSDS) among workers on leave of the absence due to their mental health problems. METHODS Participants were recruited at a psychiatric outpatient clinic for return-to-work in Tokyo, Japan, during September to November 2009. 81 outpatients were recruited, 55 of whom (68%) agreed to participate in this study. Participants answered questionnaires including WBI, MDQ, BSDS, and demographic factors. Their diagnostic information according to the international statistical classification of diseases and related health problems 10th revision (ICD-10) was obtained from their attending psychiatrists. The WBI is a new self-rating 39-item questionnaire which developed with input from occupational mental health specialists and an analysis of WHO Composite International Diagnostic Interview (CIDI) items. The WBI contains 3 subtype scales: WBI-A (5 items), WBI-AB4 (9 items), and WBI-AB (39 items). RESULTS Reliability of these scales was moderate. In the AUC of these scales, BSDS was the best of them (0.83). In the optimal cut-off point of these scales, WBI-AB4 showed good efficiency of screening (sensitivity=0.78, specificity=0.75). Both MDQ and BSDS had high specificity, while low in sensitivity. LIMITATIONS The well validated diagnostic method (i.e., the structured clinical interview for DSM-IV [SCID] or CIDI) was not applied in this study. CONCLUSIONS The WBI, especially WBI-AB4 would be a useful workplace screening tool for workers with bipolar disorder.

Effects of an internet-based cognitive behavioural therapy intervention on preventing major depressive episodes among workers: a protocol for a randomised controlled trial

Introduction The aim of this study is to examine the effects of an internet-based cognitive behavioural therapy (iCBT) program on decreasing the risk of major depressive episodes (MDEs) among workers employed in a private corporate group in Japan, using a randomised controlled trial design. Methods and analysis All of the workers in a corporate group (n=20 000) will be recruited through an invitation email. Participants who fulfil the inclusion criteria will be randomly allocated to intervention or control groups (planned N=4050 for each group). They will be allowed to complete the six lessons of the iCBT program within 10 weeks after the baseline survey. Those in the control group will receive the same iCBT after 12 months. The program includes several CBT skills: self-monitoring, cognitive restructuring, assertiveness, problem-solving and relaxation. The primary outcome measure is no new onset of MDE (using Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR)/DSM-5 criteria) during the 12-month follow-up. Assessment will use the web version of the WHO Composite International Diagnostic Interview V.3.0 depression section. Ethics and dissemination The Research Ethics Review Board of Graduate School of Medicine, the University of Tokyo (No. 3083-(2)), approved the study procedures. Trial registration number The study protocol is registered at the UMIN Clinical Trials Registry (UMIN-CTR; ID=UMIN000014146).