Cost of depression among adults in Japan in 2005.

AIM: Major depression is expected to become the leading contributor to disease burden worldwide by 2020. Previous studies have shown that the societal cost of depression is not less than that of other major illnesses, such as cardiovascular diseases or AIDS. Nevertheless, the cost of depression in Japan has never been examined. The goal of the present study was to estimate the total cost of depression in Japan and to clarify the characteristics of this burden. METHODS: A prevalence-based approach was adopted to measure the total cost of depression. The total cost of depression was regarded as being comprised of the direct cost, morbidity cost and mortality cost. Diagnoses included in this study were depressive episodes and recurrent depressive disorder according to the ICD-10 or major depressive disorder according to the DSM-IV. Data were collected from publicly available statistics and the World Mental Health Japan Survey database. RESULTS: The total cost of depression among adults in Japan in 2005 was estimated to be ¥2.0 trillion. The direct cost was ¥0.18 trillion. The morbidity cost was ¥0.92 trillion, while the mortality cost was ¥0.88 trillion. CONCLUSION: The societal costs caused by depression in Japan are enormous, as in other developed countries. Low morbidity costs and extremely high mortality costs are characteristic in Japan. Effective interventions for preventing suicide could reduce the societal costs of depression.

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.

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.

Prevalence and correlates of illicit and non-medical use of psychotropic drugs in Japan: findings from the World Mental Health Japan Survey 2002-2004.

PURPOSE: To describe the prevalence of illicit and non-medical use of drugs, the age of first use, and their correlates in the general population of Japan, based on data collected between 2002 and 2004 as part of the World Mental Health (WMH) surveys. METHODS: Participants included were a subsample (n = 887) of the total 2,436 Japanese-speaking respondents aged >or=20 years, randomly sampled from residents in seven cities/municipalities in Japan. Face-to-face household surveys were conducted using the Japanese version of the fully structured WHO WMH Survey Initiative version of the Composite International Diagnostic Interview. RESULTS: Lifetime prevalence of marijuana and cocaine use, non-medical use of prescribed drugs such as tranquilizers, stimulants and analgesics, and use of other substances was 1.5, 0.3, 6.4 and 2.4%, respectively. Lifetime use of marijuana was significantly greater among men. Prescription drug abuse/misuse was significantly more common among the middle-aged (35-49 years) group and those who were married/cohabitating. The 12-month prevalence of marijuana and non-medical use was 0.3 and 1.9%, respectively. Age of first use was likely to be early adulthood. Non-medical use was significantly related to mood disorder, anxiety disorder, intermittent explosive disorder and alcohol abuse/dependence. CONCLUSIONS: The present study confirmed lower prevalence of drug use in Japan than in other countries, such as the United States. However, the non-medical use of psychotropic drugs seems more common in Japan.

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 back-translaton 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.

Heart disease, other circulatory diseases, and onset of major depression among community residents in Japan: results of the World Mental Health Survey Japan 2002-2004.

We examined whether selected circulatory diseases (heart disease, stroke, diabetes and hypertension) were associated with an increased risk of major depression in the Japanese community population. Face-to-face household surveys were carried out in 7 areas, and a total of 2,436 persons participated (overall response rate: 58.4%) from 2002 to 2004. The WHO Composite International Diagnostic Interview 3.0 was used to diagnose major depression according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, and additional interviews assessed the presence of circulatory diseases. Using data from a random subsample of the respondents (n=832), we conducted Cox proportional hazards models to calculate hazard ratios for the onset of major depression with comorbid circulatory diseases as a time-dependent covariate. Heart attack was significantly associated with the onset of major depression (hazard ratio [HR], 7.51 [95% Confidential Interval (CI), 1.36-41.45]) after adjusting for sex, birth cohort, smoking, alcohol intake, and education. Heart disease (HR, 2.12 [95% CI, 0.79-5.70]), diabetes (HR, 2.36 [95% CI, 0.42-13.34]) and hypertension (HR, 0.97 [95% CI, 0.37, 2.50]) were not significantly associated. There were no subjects who developed major depression after stroke. These results suggest that heart attack, and maybe also heart disease and diabetes, affect the onset of major depression.

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. METHODS: Important suicide-related outcomes and risk factors were assessed in face-to-face interviews with 2436 adult respondents in seven areas as part of the World Health Organization (WHO) World Mental Health Survey Initiative. Mental disorders were assessed with the WHO Composite International Diagnostic Interview (CIDI). RESULTS: The lifetime prevalence estimates of suicidal ideation, plans, and attempts were 10.9%, 2.1%, and 1.9%, respectively. Risk of suicide plans and attempts was highest when suicidal ideation occurred at an early age and within the first year of ideation. In middle-aged individuals, the period after first employment and the presence of mental disorders were risk factors. CONCLUSIONS: Risk of suicide plans and attempts is highest when suicidal ideation occurred at an earlier age and within the first year of ideation. Mental disorders are as predictive of the suicide-related outcomes examined here, and comorbidity is an important predictor.

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.

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 >or=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.

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.

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.