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.

[Lifetime prevalence and correlates of schizophrenia and disorders with psychotic symptoms in the general population of Izmir, Turkey].

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.

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.

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.