Takehiko Kikkawa

The performance of the Japanese version of the K6 and K10 in the World Mental Health Survey Japan

Two new screening scales for psychological distress, the K6 and K10, have been developed using the item response theory and shown to outperform existing screeners in English. We developed their Japanese versions using the standard backtranslaton method and included them in the World Mental Health Survey Japan (WMH‐J), which is a psychiatric epidemiologic study conducted in seven communities across Japan with 2436 participants. The WMH‐J used the WMH Survey Initiative version of the Composite International Diagnostic Interview (CIDI) to assess the 30‐day Diagnostic and Statistical Manual of Mental Disorders – Fourth Edition (DSM‐IV). Performance of the two screening scales in detecting DSM‐IV mood and anxiety disorders, as assessed by the areas under receiver operating characteristic curves (AUCs), was excellent, with values as high as 0.94 (95% confidence interval = 0.88 to 0.99) for K6 and 0.94 (0.88 to 0.995) for K10. Stratum‐specific likelihood ratios (SSLRs), which express screening test characteristics and can be used to produce individual‐level predicted probabilities of being a case from screening scale scores and pretest probabilities in other samples, were strikingly similar between the Japanese and the original versions. The Japanese versions of the K6 and K10 thus demonstrated screening performances essentially equivalent to those of the original English versions. Copyright

Twelve-month prevalence, severity, and treatment of common mental disorders in communities in Japan: preliminary finding from the World Mental Health Japan Survey 2002-2003.

Abstract  To estimate the prevalence, severity, and treatment of Diagnostic and Statistical Manual of Mental Disorders (4th edn; DSM‐IV) mental disorders in community populations in Japan, face‐to‐face household surveys were conducted in four community populations in Japan. A total of 1663 community adults responded (overall response rate, 56%). The DSM‐IV disorders, severity, and treatment were assessed with the World Mental Health version of the World Health Organization (WHO) Composite International Diagnostic Interview (WMH‐CIDI), a fully structured lay‐administered psychiatric diagnostic interview. The prevalence of any WMH‐CIDI/DSM‐IV disorder in the prior year was 8.8%, of which 17% of cases were severe and 47% were moderate. Among specific disorders, major depression (2.9%), specific phobia (2.7%), and alcohol abuse/dependence (2.0%) were the most prevalent. Although disorder severity was correlated with probability of treatment, only 19% of the serious or moderate cases received medical treatment in the 12 months before the interview. Older and not currently married individuals had a greater risk of having more severe DSM‐IV disorders if they had experienced any within the previous 12 months. Those who had completed high school or some college were more likely to seek medical treatment than those who had completed college. The study confirmed that the prevalence of DSM‐IV mental disorders was equal to that observed in Asian countries but lower than that in Western countries. The percentage of those receiving medical treatment was low even for those who suffered severe or moderate disorders. Possible strategies are discussed.

Social Class Inequalities in Self-rated Health and Their Gender and Age Group Differences in Japan

BACKGROUND Few studies have examined social inequalities in self-rated health in Japan, and the issue of gender differences related to social inequalities in self-rated health remains inconclusive. METHODS The data derived from interviews with 2987 randomly selected Japanese adults in four prefectures in Japan who completed the cross-national World Mental Health survey from 2002 through 2005. We calculated odds ratios (ORs) of having poor self-rated physical and mental health by two social class indicators independently with multivariate logistic regression models, adjusted for age, gender, marital status, and area. Stratified analyses by gender and age group were also conducted. RESULTS The adjusted ORs of the lowest educational attainment category having poor self-rated physical and mental health were 1.42 (95% confidence interval [CI]: 1.15-1.76) and 1.37 (95% CI: 1.10-1.70), respectively. Among females, educational attainment had significant linear associations with self-rated physical and mental health. Adjusted household income was also significantly associated with self-rated physical health among female respondents. No associations were found among males. While educational attainment was associated with self-rated health among the young age group, adjusted household income was associated with self-rated physical health in the middle and old age group. CONCLUSION These results indicated social inequalities in self-rated health and prominent social inequalities in self-rated health among females in Japan. Social inequalities in self-rated health seemed to exist across age groups. However, the mechanism of social inequalities in self-rated health could be different depending on the age group.

Twelve‐month use of mental health services in four areas in Japan: Findings from the World Mental Health Japan Survey 2002–2003

Abstract  The aim of the present study was to provide basic descriptive data regarding utilization of 12‐month mental health services in the Japanese community population. Face‐to‐face household surveys were carried out in four areas (two urban cities and two rural municipalities), and a total of 1663 persons participated (overall response rate: 56.4%). For data collection, the structured psychiatric interview, World Mental Health version of the World Health Organization Composite International Diagnostic Interview (WMH‐CIDI) was used, allowing DSM‐IV diagnoses, severity, and service utilization. It was found that 7.3% of total respondents had received any service, either professional or non‐professional, in the past 12 months, including 20.0% of those with 12‐month DSM‐IV disorders and 6.2% of those without. Thirty‐three percent of those with any mood disorder used any service, and 26.8% of those used some type of health care. The probability of people with 13–15 years of education receiving mental health treatment was fourfold higher than those with ≥16 years of education. Gender, age, or income were not found to contribute to utilization of mental health services. The results confirm that the majority of people with a recent psychiatric disorder have not used mental health care or other support systems. The mental health care system in Japan has improved over the past decade, but not enough for people suffering from mental disturbances.

Prevalence of and risk factors for suicide-related outcomes in the World Health Organization World Mental Health Surveys Japan

Aim:  Suicide is a major public health concern in Japan but little is known about the prevalence of and risk factors for suicidal ideation, plans, and attempts. The aim of the present study was to clarify the prevalence of and risk factors for important suicide‐related outcomes.

Evaluation of the DSM-IV and ICD-10 Criteria for Depressive Disorders in a Community Population in Japan Using Item Response Theory

The DSM‐IV and ICD‐10 are both operational diagnostic systems that classify known psychological disorders according to the number of criteria symptoms. Certain discrepancies between the criteria exist and may lead to some inconsistencies in psychiatric research. The purpose of this study was to investigate these differences in the assessment of depression with item response theory (IRT) analyses. The World Mental Health‐Japan (WMHJ) Survey is an epidemiological survey of the general population in Japan. We analyzed data from the WMHJ completed by 353 respondents who had either depressive mood or diminished interest. A two‐parameter logistic model was used to evaluate the characteristics of the symptoms of the DSM‐IV and ICD‐10. IRT analyses revealed that the symptoms about psychomotor activity, worthlessness and self‐reproach were more informative and suggestive of greater severity, while the symptoms about dietary habits were less informative. IRT analyses also revealed that the ICD‐10 seems more sensitive to the mild range of the depression spectrum compared to the DSM‐IV. Although there were some variations in severity among respondents, most of the respondents diagnosed with a severe or moderate depressive episode according to the ICD‐10 were also diagnosed with a major depressive episode according to the DSM‐IV.

Impact of mental disorders on work performance in a community sample of workers in Japan: the World Mental Health Japan Survey 2002-2005.

Most studies that investigate the impact of mental disorders on work performance have been conducted in Western countries, but this study examines the impact of common mental disorders on sick leave and on-the-job work performance in a community sample of Japanese workers. Data from the World Mental Health Japan survey were analyzed. A subsample of 530 workers aged 20-60years were interviewed using the WHO Composite International Diagnostic Interview 3.0. The WHO Health and Work Performance Questionnaire, was used to assess sick days and on-the-job work performance for the previous 30days. Linear regression was used to estimate the impact of mental disorders on these indicators of work performance over 12months. Mood disorders, including major depressive disorder, and alcohol abuse/dependence were significantly associated with decreased on-the-job performance. There were no significant associations between mental disorders and sick/absent days. Consistent with previous studies, major depression has a great impact on on-the-job work performance in Japan. The lost productivity was estimated at approximately 28-30 lost days per year. A similar decrease in on-the-job work performance was found for alcohol abuse/dependence, which is stronger than that in other countries, probably attributable to greater tolerance of problematic drinking at Japanese worksites.

Lifetime comorbidities between phobic disorders and major depression in Japan: results from the World Mental Health Japan 2002–2004 Survey

Background: Although often considered of minor significance in themselves, evidence exists that early‐onset phobic disorders might be predictors of later more serious disorders, such as major depressive disorder (MDD). The purpose of this study is to investigate the association of phobic disorders with the onset of MDD in the community in Japan. Methods: Data from the World Mental Health Japan 2002–2004 Survey were analyzed. A total of 2,436 community residents aged 20 and older were interviewed using the WHO Composite International Diagnostic Interview 3.0 (response rate, 58.4%). A Cox proportional hazard model was used to predict the onset of MDD as a function of prior history of DSM‐IV specific phobia, agoraphobia, or social phobia, adjusting for gender, birth‐cohort, other anxiety disorders, education, and marital status at survey. Results: Social phobia was strongly associated with the subsequent onset of MDD (hazard ratio [HR]=4.1 [95% CI: 2.0–8.7]) after adjusting for sex, birth cohort, and the number of other anxiety disorders. The association between agoraphobia or specific phobia and MDD was not statistically significant after adjusting for these variables. Conclusions: Social phobia is a powerful predictor of the subsequent first onset of MDD in Japan. Although this finding argues against a simple neurobiological model and in favor of a model in which the cultural meanings of phobia play a part in promoting MDD, an elucidation of causal pathways will require more fine‐grained comparative research. Depression and Anxiety, 2009. Published 2009 Wiley‐liss, Inc.

Factors influencing suicidal ideation among Japanese adults: From the national survey by the Cabinet Office

Aim:  Suicide prevention is of pressing importance in Japan, and grappling with this problem necessitates clarifying the causes of suicidal ideation. The purpose of the present study was to investigate several factors influencing suicidal ideation. This was done through analyzing factors examined in prior research and accessing suicide sites.

A preliminary study on the attitude of the Japanese public towards creative artwork by people with mental illness.

Background: Although researchers have suggested that consumer art can help reduce the stigma of mental illness, there is little evidence of the attitudes of the Japanese public towards such artwork. Material: A total of 277 Japanese visitors attending an exhibition of visual arts by people with mental illness completed a short questionnaire. Discussion: After their visit, approximately 87% of the participants reported being strongly or fairly impressed by the creative art. Word frequency analysis implied generally positive attitudes towards the works. Conclusions: The Japanese public might generally have positive and empathetic attitudes towards artwork by people with mental illness.