The epidemiology of major depressive disorder and subthreshold depression in Izmir, Turkey: Prevalence, socioeconomic differences, impairment and help-seeking.

BACKGROUND: Subclinical and clinical depression is common, widely distributed in the general population, and usually associated with role impairment and help-seeking. Reliable information at the population level is needed to estimate the disease burden of depression and associated care needs in Turkey. METHOD: The cross-sectional study aimed to assess the prevalence of subthreshold (SubD) and clinical major depressive disorder (MDD) in Izmir, Turkey. In the 5242 eligible households, a total of 4011 individuals were successfully interviewed, yielding a response rate of 76.5%. Prevalence estimates of MDD and SubD depression were formed by using the responses to the questions of the CIDI section E. Short Form 36 (SF-36) to assess health status and functional impairments in eight scaled scores during the last four weeks. All respondents were questioned about receiving 12-month treatment for any psychological complaints, the route of help-seeking, as well as prescribed medicines and any hospitalization. RESULTS: The one year prevalence estimate for CIDI/DSM IV MDD was 8.2% (95% CI, 7.4-9.1). Less educated, low income, uninsured, low SES, unemployed/disabled and housewives, slum area residents had higher one year MDD prevalence. Determined prevalence of help seeking from mental health services of SubD and MDD cases were 23.6%, 30.6% respectively. Only 24.8% of clinically depressive patients received minimally adequate treatment. LIMITATIONS: Cross sectional design. CONCLUSION: Higher MDD prevalence correlates with younger ages, female gender, unemployment, less education, lower monthly income, lower SES and uninsurance. Help seeking from mental health services were low. There are treatment gap and impairment in depressive group.

[Lifetime prevalence and correlates of schizophrenia and disorders with psychotic symptoms in the general population of Izmir, Turkey]. / Izmir kent merkezinde sizofreni ve psikotik belirtili bozukluklarin yasamboyu yayginligi ve iliskili olduklari sosyodemografik özellikler.

OBJECTIVE: To estimate the lifetime prevalence of 12 DSM-IV disorders with psychotic symptoms in a general population survey. METHOD: Addresses were contacted in a multistage clustered area probability sampling frame of administrative neighbourhoods and households, covering 9 districts and 302 neighbourhoods in the Izmir metropolitan area between November 2007 and October 2008. One household member aged between 15 and 64 years and available to complete the interview was randomly selected using a within-household sampling method. The primary screening instrument was the Composite International Diagnostic Interview 2.1. A systematic screening procedure was implemented to detect probable cases with any psychotic disorder. Those selected by the screens were re-interviewed with the Structured Clinical Interview for DSM-IV. Diagnoses of individuals who were not available for re-interview were made by combining screening information with case register diagnoses and/or the telephone interviews with relatives or spouse. RESULTS: A total of 4011 individuals were screened for disorders with psychotic symptoms. After screening, 499 respondents were selected as a probable case. 277 of screen positive respondents were available for clinical reappraisal. Initial screening interviews and additional material were used for best estimate diagnoses of the remaining 172 respondents. Total lifetime prevalence of 12 DSM-IV disorders with psychotic symptoms was 2.62%. Lifetime prevalence of each disorder separately were as follows: 0.74% for schizophrenia, 0.20% for schizoaffective disorder, 0.05% for schizophreniform disorder, 0.10% for delusional disorder, 0.12% for brief psychotic disorder, 0.55% for major depressive disorder with psychotic features, 0.37% for bipolar I disorder, 0.20% for substance induced psychotic disorder, and 0.07% for psychotic disorders due to a general medical condition. CONCLUSION: Total lifetime prevalence of disorders with psychotic symptoms is higher than any previously reported estimates in Turkey; with a prevalence of approximately 2.5%, these disorders can be considered a major public health concern.

Testing the psychosis continuum: differential impact of genetic and nongenetic risk factors and comorbid psychopathology across the entire spectrum of psychosis.

A growing number of studies demonstrate high rates of subthreshold psychotic experiences, but there is considerable heterogeneity in rates due to study cohort and design factors, obscuring how prevalent psychotic experiences may or may not relate to rare psychotic disorders. In a representative general population sample (n = 4011) in Izmir, Turkey, the full spectrum of expression of psychosis was categorized across 5 groups representing (1) absence of psychosis, (2) subclinical psychotic experiences, (3) low-impact psychotic symptoms, (4) high-impact psychotic symptoms, and (5) full-blown clinical psychotic disorder and analyzed for continuity and discontinuity in relation to (1) other symptom dimensions associated with psychotic disorder and (2) proxies of genetic and nongenetic etiology. Results were tested for linear and extralinear contrasts between clinical and nonclinical and between disorder and nondisorder expression of psychosis. Demographic variables, indexing premorbid social adjustment and socioeconomic status, impacted mostly linearly; proxy variables of genetic loading (more or more severely affected relatives) impacted in a positive extralinear fashion; environmental risk factors sometimes impacted linearly (urbanicity and childhood adversity) and sometimes extralinearly (cannabis), occasioning a disproportional shift in risk at the clinical disorder end of the spectrum. Affective symptoms were associated with a disproportionally higher risk below the disorder threshold, whereas a disproportionally higher risk above the threshold was associated with psychotic symptom load, negative symptoms, disorganization, and visible signs of mental illness. Liability associated with respectively affective and nonaffective symptom domains, in interaction with environmental risks, may operate by impacting differentially over a quasi-continuous extended psychosis phenotype in the population.

Izmir mental health survey for gene-environment interaction in psychoses (TürkSch): objectives and methodology.

OBJECTIVE: To describe the objectives and design of a multistage study on the prevalence and risk factors of mental health problems, in particular psychotic disorders and psychotic symptoms, by assessing a probabilistic sample of household residents in the Izmir Metropolitan Area, aged 15-64 years. METHOD: The study included three different observation frames. In the first stage, of which methodology is in the focus of this paper, the primary screening instrument was the Composite International Diagnostic Interview 2.1, which assesses lifetime and/or last one year occurrence of several DSM-IV disorders. Second, a parallel survey of social capital of administrative wards was conducted in the same neighbourhoods. Third, a nested-case control study was performed to study effects of genetic and environmental risk factors on wide psychosis phenotype. RESULTS: A total of 4011 males and females were contacted through a multistage clustered area probability sample of administrative neighbourhoods and households, covering 9 districts and 302 neighbourhoods. The response rate for the first stage was 76.5% in 5242 eligible households. Respondents were interviewed at home in 2008 for the screening of included mental health problems. The screened disorders were mood disorders (last 1 year), schizophrenia and other non-affective psychotic disorders (lifetime), and dependence and abuse of psychoactive substances (lifetime). CONCLUSION: Although cross-sectional in nature, the TürkSch has a unique study design and yields data of high quality. This enables study of the prevalence, risk and higher-order interactions underlying ill-health in the Turkish population, with a specific focus on psychosis.