Tolga Binbay

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.

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.

Evidence that the wider social environment moderates the association between familial liability and psychosis spectrum outcome.

BACKGROUND Familial liability to both severe and common mental disorder predicts psychotic disorder and psychotic symptoms, and may be used as a proxy in models examining interaction between genetic risk and the environment at individual and contextual levels. METHOD In a representative general population sample (n=4011) in Izmir, Turkey, the full spectrum of expression of psychosis representing (0) no symptoms, (1) subclinical psychotic experiences, (2) low-impact psychotic symptoms, (3) high-impact psychotic symptoms and (4) full-blown clinical psychotic disorder was assessed in relation to mental health problems in the family (proxy for familial liability) and the wider social environment. Quality of the wider social environment was assessed in an independent sample using contextual measures of informal social control, social disorganization, unemployment and low income, aggregated to the neighbourhood level. RESULTS The association between familial liability to severe mental illness and expression of psychosis spectrum was stronger in more deprived neighbourhoods [e.g. this association increased from β=0.33 (p=0.01) in low-unemployment neighbourhoods to β=0.92 (p<0.001) in high-unemployment neighbourhoods] and in neighbourhoods high in social control, while neighbourhood variables did not modify the association between familial liability to common mental disorder and the psychosis outcome. Neighbourhood variables mediated urbanicity effects. CONCLUSIONS Contextual effects may be important in moderating the expression of psychosis liability in populations, representing a specific pathway independent of the link between common mental disorder and psychosis.

Formal thought disorder in schizophrenia and bipolar disorder: A systematic review and meta-analysis

Historically, formal thought disorder has been considered as one of the distinctive symptoms of schizophrenia. However, research in last few decades suggested that there is a considerable clinical and neurobiological overlap between schizophrenia and bipolar disorder (BP). We conducted a meta-analysis of studies comparing positive (PTD) and negative formal thought disorder (NTD) in schizophrenia and BP. We included 19 studies comparing 715 schizophrenia and 474 BP patients. In the acute inpatient samples, there was no significant difference in the severity of PTD (d=-0.07, CI=-0.22-0.09) between schizophrenia and BP. In stable patients, schizophrenia was associated with increased PTD compared to BP (d=1.02, CI=0.35-1.70). NTD was significantly more severe (d=0.80, CI=0.52-0.1.08) in schizophrenia compared to BP. Our findings suggest that PTD is a shared feature of both schizophrenia and BP but persistent PTD or NTD can distinguish subgroups of schizophrenia from BP and schizophrenia patients with better clinical outcomes.

Formal thought disorder in first-episode psychosis.

Formal thought disorder (FTD) is one of the fundamental symptom clusters of schizophrenia and it was found to be the strongest predictor determining conversion from first-episode acute transient psychotic disorder to schizophrenia. Our goal in the present study was to compare a first-episode psychosis (FEP) sample to a healthy control group in relation to subtypes of FTD. Fifty six patients aged between 15 and 45years with FEP and forty five control subjects were included in the study. All the patients were under medication for less than six weeks or drug-naive. FTD was assessed using the Thought and Language Index (TLI), which is composed of impoverishment of thought and disorganization of thought subscales. FEP patients showed significantly higher scores on the items of poverty of speech, weakening of goal, perseveration, looseness, peculiar word use, peculiar sentence construction and peculiar logic compared to controls. Poverty of speech, perseveration and peculiar word use were the significant factors differentiating FEP patients from controls when controlling for years of education, family history of psychosis and drug abuse.

Relation of formal thought disorder to symptomatic remission and social functioning in schizophrenia

OBJECTIVE The aim of this cross-sectional study is to examine the relation of formal thought disorder (FTD) with symptomatic remission (SR) and social functioning in patients with schizophrenia. METHOD The study was carried out with a sample consisting of 117 patients diagnosed with schizophrenia according to DSM-IV. The patients were assessed with the Positive and Negative Syndrome Scale (PANSS), the Thought and Language Index (TLI), and the Personal and Social Performance Scale (PSP). We used logistic regression in order to determine the relation between FTD and SR and linear regression to identify the strength of association between FTD and social functioning. RESULTS Logistic regression analysis revealed that poverty of speech (odds ratio: 1.47, p<0.01) and peculiar logic (odds ratio: 1.66, p=0.01) differentiated the remitted patients from the non-remitted ones. Linear regression analysis showed that the PSP total score was associated with poverty of speech and peculiar logic items of the TLI (B=-0.23, p<0.01, B=-0.24, p=0.01, respectively). CONCLUSION Our findings suggest that poverty of speech and peculiar logic are the specific domains of FTD which are related to both SR status and social functioning in patients with schizophrenia.

Is BDNF-Val66Met polymorphism associated with psychotic experiences and psychotic disorder outcome? Evidence from a 6 years prospective population-based cohort study

There is little research on genetic risk for the extended psychosis phenotype ranging from psychotic experiences (PEs) to psychotic disorders (PDs). In this general population‐based prospective cohort study, the longitudinal associations between BDNF‐Val66Met polymorphism and the different levels of the extended psychosis phenotype were investigated. Addresses were contacted in a multistage clustered probability sampling frame covering 11 districts and 302 neighborhoods at baseline (n = 4011). A nested case‐control study (n = 366) recruited individuals with PEs and PDs as well as individuals with no psychotic symptoms. In this subgroup, blood sampling for genetic analysis and assessment of environmental exposures were carried out, followed by clinical re‐appraisal at follow‐up 6 years later (n = 254). The BDNF‐Val66Met polymorphism was significantly associated with the extended psychosis phenotype. The pattern of the association was that the BDNF‐Val66Met polymorphism impacted in a dose‐response but extra‐linear fashion, with stronger impact at the PD end of the extended psychosis phenotype. Associations were still significant after adjusting for sociodemographic factors and environmental exposures including life events, childhood adversity, socioeconomic status, urbanicity, and cannabis use. The BDNF‐Val66Met polymorphism may index susceptibility to expression of psychosis along a spectrum.

Prevalence of premenstrual syndrome and its relationship to depressive symptoms in first-year university students

Objectives: To determine the prevalence of and factors influencing premenstrual syndrome (PMS) in first-year students at a university health campus and to evaluate the relationship between depression and PMS. Methods: This cross-sectional study was conducted on a population of 618 university students from March to June 2016 at Dokuz Eylül University, Izmir, Turkey. Data were collected using the Premenstrual Syndrome Scale (PMSS), Beck Depression Inventory and Student Identification Form. The data were analyzed with Version 20.0 of the Statistical Package for the Social Science. Descriptive statistics, Pearson’s chi-square test, and Chi-square test for trend, and independent samples t test and logistic regression analysis were used. Results: The prevalence of PMS in the university students was 58.1%. Premenstrual syndrome was significantly higher in students who smoked, drink alcohol, and consumed a large amount of fatty and high-calorie foods, in students who had a bad to very bad perception of their economic situation, and those who had any chronic disease or anemia (p<0.05). Premenstrual syndrome was significantly higher in students who had a risk of depression (p<0.01). A statistically significant relationship was determined between the risk of depression and PMSS total score and all PMSS subscale scores except for appetite changes (p<0.01). Conclusion: Premenstrual syndrome was found in more than half of the students who participated in the study. Premenstrual syndrome was higher in students who had a chronic disease and/or an unhealthy lifestyle. There was a statistically significant relationship between PMS and risk of depression. Students who have PMS symptoms should be evaluated for the risk of depression.

Do clinical features relate to theory of mind, empathy and 2D:4D in schizophrenia?

ABSTRACT OBJECTIVE: Digit ratios may be accepted as an indicator of level of prenatal androgen exposure during the fetal developmental period. Female-typical digit ratios have been suggested to be associated with better mentalizing and empathic abilities in general population. Recently, a number of studies have investigated the ratio of hand’s second and fourth digit fingers (2D:4D) in schizophrenia. The aim of this study was to investigate the hypothesis that positive symptoms are related to female-biased 2D:4D and relatively less impaired social cognition in schizophrenia, negative dimension is related to male-biased 2D:4D ratio and more pronounced deficits in social cognition. METHOD: The study was carried out in 48 patients with schizophrenia and 48 healthy controls. Patients were evaluated by Positive and Negative Syndrome Scale (PANSS). A digital caliper was used to measure 2D:4D finger lengths and social cognitive abilities were assessed using the Empathy Quotient (EQ) test and Reading Mind in the Eyes Test (RMET). RESULTS: Patients with schizophrenia had increased left 2D:4D finger lengths and showed poor theory of mind (ToM) and empathic abilities compared to healthy controls (p < 0.05). It was found that negative symptoms but not male-biased 2D:4D ratio were significantly associated with impaired RMET performance (p < 0.05). CONCLUSION: The present study indicates that negative dimension is negatively related to the severity of deficits in social cognition in schizophrenia. There was no evidence for a significant effect of sexual dimorphism as measured by digit ratio on social cognition and symptoms in schizophrenia.

The Relation of Thought-language Disorders in Schizophrenia with Remission of Symptoms and Psychosocial Improvement

Objective Thought and language disorders are one of the fundamental symptom clusters of schizophrenia. Thought disorders that exacerbate in acute episodes might persist during the illness chronically in a vague form. In severe mental disorders such as schizophrenia, psychosocial functioning is an important dimension as well along with symptoms in phases of diagnosis and assessment. The aim of this study is to investigate the relation of thought and language disorders seen in schizophrenia with the course of symptomatic remission (SR) and psychosocial functioning. Method The study was carried out with the sample consisted of 117 patients diagnosed with schizophrenia according to DSM-IV-TR. The patients were assessed with the Positive and Negative Syndrome Scale (PANSS), the Thought and Language Index (TLI) and the Personal and Social Performance Scale (PSP). Results Statistical significance was found between patients in SR and patients not in SR in terms of poverty of speech, weakening of goal, peculiar logic, impoverishment of thought and disorganization of thought. Peculiar logic, peculiar sentence construction and especially poverty of speech indicating negative formal thought disorder were found to predict the dimensions of psychososcial functioning. Conclusion Patients in SR show less impoverishment of thought/speech and disorganization of thought compared to patients not in SR. Thought and language disorders are significantly correlated with psychosocial dysfunctioning in schizophrenia. Social activities, personal/social relations and aggressive behaviors are associated aspects with impoverishment of thought and disorganization of thought.