The surprisingly rich contours of schizophrenia epidemiology

Queensland Centre for Mental Health Research, University of Queensland, Wacol, QLD 4076, Australia.
Archives of General Psychiatry (Impact Factor: 13.75). 02/2007; 64(1):14-6. DOI: 10.1001/archpsyc.64.1.14
Source: PubMed

ABSTRACT ESEARCHERS LIKE TO BE surprised by the data. When new data challenge old beliefs, the field becomes primed for discovery. The aim of this commentary is to let the broader psychiatric community know about recent discoveries in schizophrenia epidemiology, and to speculate on how best to leverage these discoveries to advance knowledge. For those who do not follow the literature closely, recent research in the epidemiology of schizophrenia may come as a surprise. The once cardinal notions that schizophrenia affects men and women equally and is found in all societies with comparable (or equal) incidence are no longer supported by the data. Schizophrenia is not the egalitarian disorder that we once thought it was.1

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    • "Schizophrenia is a common and devastating mental illness with a lifetime incidence rate of about 1% throughout the global population . Temporal, geographic, and population variations in this incidence rate have yielded clues to some of the possible etiologies of schizophrenia [1]. Perhaps the most well established variation in the topography of schizophrenia incidence rates is the increased rate associated with a winter-spring birth (in the northern hemisphere ) [2], which is roughly 10% higher than the 1% yearly base incidence rate for schizophrenia (i.e., the absolute winter-spring risk is 1.1%). "
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    ABSTRACT: The season of birth risk factor for schizophrenia exerts a pervasive effect on the global population, particularly at northerly latitudes. The winter infection hypothesis and the low vitamin D hypothesis are both compelling but lack conclusive clinical data. The present work develops a maternal–fetal chronobiological hypothesis for this season of birth risk factor and its prevention by maternal bright light treatment. Around the winter solstice, due to decreased sunlight, the chronobiological apparatus of the at-risk second trimester mother is characterized by a reduced amplitude circadian pacemaker, and a reduced maximum of her nocturnal plasma melatonin concentrations (MTmax) and an increased minimum of her nocturnal core body temperatures (Tmin)—both of which exert adverse effects on the fetal hippocampus and dorsal striatum. The consequences for the fetus include reduced volume and increased excitability of the hippocampus, ventral striatal dysfunction, increased presynaptic nigrostriatal dopamine transmission, and increased propensity for pathological nigrostriatal neuronal phasic firing. Thus, the maternal–fetal chronobiological hypothesis fully accounts for the fetal precursors of the major pathognomonic abnormalities in adults with schizophrenia. Bright light treatment for the second trimester mother around the winter solstice, by increasing maternal circadian amplitude, could possibly prevent the fetal hippocampal and striatal abnormalities and eliminate the season of birth risk factor for schizophrenia.
    Medical Hypotheses 10/2014; 83(6). DOI:10.1016/j.mehy.2014.10.014 · 1.07 Impact Factor
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    • "In recent years, considerable improvements have been established in psychosis epidemiology (McGrath 2007). Such an advance has enough impact to transform the commonly accepted knowledge on psychotic disorders, even in textbooks (McGrath 2005). "
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    ABSTRACT: To provide prevalence estimate, admission rates and related features of psychotic disorders in Turkey. Studies with data on prevalence and/or rates in outpatient or inpatient admissions after 1990 were included. Strings of ([schizo*OR psych*] AND Turkey) were used in PubMed and PsychINFO to detect relevant studies. Turkish Medical and Psychiatry indexes were screened with Turkish keywords. Abstract books of national congresses, national index of thesis, and references of the included papers were searched for additional data. Results were presented as prevalence per 1000 and median values of admission rates. A total of 56 studies were included, including 8 cross-sectional (4 core and 4 special group), 27 outpatient and 21 inpatient admission estimates or rates. The lifetime prevalence of schizophrenia in general population (pooled data, n: 6022) was 8.9 per 1000 (Standard error [SE]: 1.2; 95% confidence interval [CI]: 6.6-11.3). Psychosis prevalence is higher in subgroups including university students, prisoners and homeless people. Patients with a diagnosis of psychotic disorder constituted 7.6% and 26.9% of adult outpatient and inpatient psychiatry admissions. However, median rates vary depending on institutional, regional, temporal and residential features. Male gender was at higher risk in all kinds of estimates and rates for all age groups. Prevalence of schizophrenia in Turkey is higher than the formerly reported estimates in different countries. Higher prevalence may be a consequence of sample properties, environmental risk exposures, and study design. However more research is needed to further elaborate the relatively higher prevalence. Nevertheless, a major part of the psychiatry services are devoted to psychotic outpatients and inpatients.
    Turk psikiyatri dergisi = Turkish journal of psychiatry 01/2011; 22(1):40-52. DOI:10.5080/u6244 · 0.43 Impact Factor
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    • "GENDER AND PSYCHOSIS – LITERATURE REVIEW It is surprising that given the clinical heterogeneity in psychotic disorders, the majority of data concerning gender exists for schizophrenia. One of the challenging statements suggests that schizophrenia equally affects both gender (lifetime risk) but other epidemiological data found prevalence male/female ratio from 1.4 (McGrath, 2007) to 2 (Myles-Worsley et al, 1999) across the world. Systematic review from Saha and colleagues (2005) did not confirm these alleged differences. "
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    ABSTRACT: Acute psychosis is diagnosed by clearly defined operational criteria embedded into international classification systems. Many studies have tried to determine the role of gender in psychosis but mainly in terms of epidemiology and course of illness, most often schizophrenia. There are however also important gender-specific differences in clinical symptoms of acute psychosis. No guidelines or treatment recommendations suggest gender as an important factor in the choice of antipsychotic treatment, which is true for all treatment modalities (antipsychotic, dose, duration). We will review shortly available literature and present some of our own research data on gender differences in clinical presentations of acute psychosis. When the diagnosis of an illness depends almost entirely on symptoms and their presentations as in the case of acute psychosis, important gender specific differences might challenge the diagnostic process as well as treatment choice and course of psychosis. Our as well as other data confirm that acute psychosis manifest itself differently in males and females. To define further the impact of observed differences we need further research into gender specific clinical and not just epidemiological variables.
    Psychiatria Danubina 06/2010; 22(2):338-42. · 0.65 Impact Factor
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