Pedro Zitko
King's College London
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Featured researches published by Pedro Zitko.
British Journal of Psychiatry | 2013
Dheeraj Rai; Pedro Zitko; Kelvyn Jones; John Lynch; Ricardo Araya
BACKGROUND The prevalence and correlates of depression vary across countries. Contextual factors such as country-level income or income inequalities have been hypothesised to contribute to these differences. AIMS To investigate associations of depression with socioeconomic factors at the country level (income inequality, gross national income) and individual (education, employment, assets and spending) level, and to investigate their relative contribution in explaining the cross-national variation in the prevalence of depression. METHOD Multilevel study using interview data of 187 496 individuals from 53 countries participating in the World Health Organization World Health Surveys. RESULTS Depression prevalence varied between 0.4 and 15.7% across countries. Individual-level factors were responsible for 86.5% of this variance but there was also reasonable variation at the country level (13.5%), which appeared to increase with decreasing economic development of countries. Gross national income or country-level income inequality had no association with depression. At the individual level, fewer material assets, lower education, female gender, economic inactivity and being divorced or widowed were associated with increased odds of depression. Greater household spending, unlike material assets, was associated with increasing odds of depression (adjusted analysis). CONCLUSIONS The variance of depression prevalence attributable to country-level factors seemed to increase with decreasing economic development of countries. However, country-level income inequality or gross national income explained little of this variation, and individual-level factors appeared more important than contextual factors as determinants of depression. The divergent relationship of assets and spending with depression emphasise that different socioeconomic measures are not interchangeable in their associations with depression.
Drug and Alcohol Dependence | 2013
Stefanos Bellos; Petros Skapinakis; Dheeraj Rai; Pedro Zitko; Ricardo Araya; Glyn Lewis; Christos Lionis; Venetsanos Mavreas
BACKGROUND Alcohol consumption is associated with several complications of both physical and mental health. Light or moderate alcohol consumption may have beneficial effects on physical or mental health but this effect is still controversial and research in the mental health field is relatively scarce. Our aim was to investigate the association between varying levels of alcohol consumption and the common mental disorders of depression and anxiety in a large international primary care sample. METHODS The sample consisted of 5438 primary care attenders from 14 countries who participated in the WHO Collaborative Study of Psychological Problems in General Health Care. Alcohol use was assessed using Alcohol Use Disorders Identification Test (AUDIT) and the mental disorders were assessed with the Composite International Diagnostic Interview (CIDI). RESULTS Light to moderate alcohol consumption was associated with a lower prevalence of depression and generalized anxiety disorder compared to abstinence while excessive alcohol consumption was associated with a higher prevalence of depression. This non-linear association was not substantially affected after adjustment for a range of possible confounding variables, including the presence of chronic disease and the current physical status of participants and was evident in different drinking cultures. CONCLUSION The study confirms that excessive drinking is associated with an increased prevalence of depression, but also raises the possibility that light/moderate drinking may be associated with a reduced prevalence of both depression and anxiety. Any causal interpretation of this association is difficult in the context of this cross-sectional study and further longitudinal studies are needed.
Psychiatry Research-neuroimaging | 2016
Stefanos Bellos; Petros Skapinakis; Dheeraj Rai; Pedro Zitko; Ricardo Araya; Glyn Lewis; Christos Lionis; Venetsanos Mavreas
BACKGROUND Several studies that have examined the full range of alcohol consumption have pointed to a possible non-linear association between alcohol use and the common mental disorders. Most of these studies are cross sectional and assessed psychiatric morbidity using non-specific instruments. Our aim was to investigate the longitudinal association between varying levels of alcohol consumption at baseline and the new-onset of depression and generalized anxiety disorder (GAD), in a large international primary care sample. METHODS The sample consisted of 3201 primary care attenders from 14 countries in the context of WHO Collaborative Study of Psychological Problems in General Health Care. Alcohol use at baseline was assessed using AUDIT and the mental disorders were assessed with the Composite International Diagnostic Interview. RESULTS Light to moderate alcohol consumption at baseline was associated with a lower incidence of depression and GAD compared to abstinence while excessive alcohol consumption was associated with a higher incidence of depression but not GAD. This non-linear association was not substantially affected after adjustment for a range of possible confounding variables. CONCLUSION Any causal interpretation of this association is difficult in the context of an observational study and further combined and consistent evidence from different sources is needed.
Revista Panamericana De Salud Publica-pan American Journal of Public Health | 2011
Báltica Cabieses; Pedro Zitko; Rafael Pinedo; Manuel Espinoza; Christo Albor
Social status (SS) is a multidimensional variable that is used widely in health research. There is no single optimal method for estimating social status. Rather, in each case the measurement may vary depending on the research subject, the base theory considered, the population of interest, the event of interest and, in some cases, the available information. This literature review develops the following topics related to SS measurement, based on the international scientific sources available electronically: i) identification of the role of SS in the context of social epidemiology research, ii) description of the principal indicators and methodological approaches used to measure SS in health research, and iii) analysis of the distinct difficulties of SS measurement in specific populations such as ethnic groups, women, children, the elderly, and in rural vs. urban contexts. The review finally makes it possible to describe some of the implications of SS measurement in Latin American countries.
Revista Medica De Chile | 2012
Jorge Nogales-Gaete; Rodrigo Aracena; Vannia Díaz; Pedro Zitko; Sergio Cepeda-Zumaeta; Paula Agurto; Carola González
Background: The detection of cognitive changes (CC) and psychiatric disorders in relapsing remitting multiple sclerosis (MS-RR) contributes to patient clinical monitoring. Aim: To assess the frequency and characteristics of CC and psychiatric disorders in Chilean patients with MS-RR, before starting immunomodulatory treatment. Patients and Methods: Retrospective review of data that was obtained following a standard assessment protocol. It consisted in the application of the Expanded Disability Status Scale of Kurtzke (EDSS), Multiple Sclerosis Functional Composite (MSFC), fatigue intensity scale of Krupp, brief repeatable battery of neuropsychological Rao (BRN-R) and Hamilton´s depression and anxiety questionnaires. Results: We evaluated 129 patients aged between 12 and 60 years of age (69% women). Ninety four percent of patients had eight or more years of schooling. The average EDSS score was 2.83. CC were detected in 62% of participants, in at least one subtest of the BRN-R. The main changes were verbal memory and speed in the processing information. The frequency of cognitive impairment (CI), defined as at least two BRN-R subtests altered, was 36%. The figures decreased to 17% when significant major depression or associated fatigue were excluded. Depressive symptoms were observed in 58% and anxiety in 76.7%. Conclusions: The results are consistent with those described in the literature. The type of instruments used in the investigation of CC and the definition of CI in MS should be standardized. (Rev Med Chile 2012; 140: 1437-1444)
Social Psychiatry and Psychiatric Epidemiology | 2017
Niina Markkula; Pedro Zitko; Sebastián Peña; Paula Margozzini; C Pedro Retamal
PurposeThere is a need for recent, nationally representative data on the prevalence of mental disorders in Latin America. We aim to assess the prevalence of depression in Chile and possible changes over time.MethodsIn the Chilean National Health Surveys in 2003 (n = 5469) and 2010 (n = 7212), two nationally representative cross-sectional population surveys, the Composite International Diagnostic Interview, Short Form (CIDI-SF) was applied to establish diagnosis of major depressive episode (MDE) using DSM-IV criteria. Sociodemographic correlates of MDE and time trends were analyzed.ResultsThe prevalence of MDE was 20.5% (95% CI 18.3–22.7) in 2003 and 18.4% (95% CI 16.5–20.2) in 2010. In 2003, women and persons residing in urban areas had increased risk of depression, whereas in 2010 the risk factors were female sex, younger age and lower education. There were up to 15-fold differences in prevalence between regions. No significant changes in prevalence occurred over the observation period. 21.2% (95% CI 16.6–25.8) of those depressed were currently receiving antidepressant treatment, with large regional variations in access to treatment.ConclusionsDepressive disorders are a pressing public health concern in Chile, and particularly women, persons with low education, and the poorer regions of the country are affected. Prompt actions are needed to address the burden of depression with sufficient resources for treatment and prevention.
Revista Panamericana De Salud Publica-pan American Journal of Public Health | 2011
Manuel Espinoza; Báltica Cabieses; César Pedreros; Pedro Zitko
This paper describes the evaluation of the first training on clinical research methodology in Chile (EMIC-Chile) 12 months after its completion. An online survey was conducted for students and the Delphi method was used for the teaching team. Among the students, the majority reported that the program had contributed to their professional development and that they had shared some of the knowledge acquired with colleagues in their workplace. Forty-one percent submitted a project to obtain research funding through a competitive grants process once they had completed the course. Among the teachers, the areas of greatest interest were the communication strategy, teaching methods, the characteristics of the teaching team, and potential strategies for making the EMIC-Chile permanent in the future. This experience could contribute to future research training initiatives for health professionals. Recognized challenges are the involvement of nonmedical professions in clinical research, the complexities associated with the distance learning methodology, and the continued presence of initiatives of this importance at the national and regional level.
Revista Medica De Chile | 2018
Francesca Borghero; Vania Martínez; Pedro Zitko; Paul A. Vöhringer; Gabriel Cavada; Graciela Rojas
BACKGROUND There is a paucity of validated instruments for screening depression in adolescent populations in Chile. AIM To determine the diagnostic accuracy of the adolescent version of Patient Health Questionnaire-9 (PHQ-9). MATERIAL AND METHODS The PHQ-9 was transculturally adapted and administered to adolescents aged 15 to 19 years residing in Santiago de Chile, who were then evaluated with a semi structured interview (Kiddie-Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version or K-SADS-PL) and the Beck Depression Inventory. Internal validity, concurrent validity, and discriminatory power of the PHQ-9 were analyzed. RESULTS We evaluated 245 adolescents aged 16.2 ± 1 years (71% females). Two hundred and ten presented with a depressive episode and 35 were healthy. The sensitivity and specificity of the scale were 86.2 and 82.9% for 11 points, with a positive likelihood ratio of 5.02. CONCLUSIONS The PHQ-9 is sensitive and specific enough to be used as a screening tool in adolescents with suspected depression. At a 11-point cut-off score as proposed, the likelihood to find a positive result in a subject with depression is five times higher.
Journal of Affective Disorders | 2018
Ricardo Araya; Pedro Zitko; Niina Markkula; Dheeraj Rai; Kelvyn Jones
BACKGROUND The relative importance of individual and country-level factors influencing access to diagnosis and treatment for depression across the world is fairly unknown. METHODS We analysed cross-national data from the WHO World Health Surveys. Depression diagnosis and access to health care were ascertained using a structured interview. Logistic Bayesian Multilevel analyses were performed to establish individual and country level factors associated with: (1) receiving a diagnosis and (2) accessing treatment for depression if a diagnosis was ascertained. RESULTS The sample included 7870 individuals from 49 countries who met ICD-10 criteria for depressive episode in the past 12 months. A third (32%) of these individuals had ever been diagnosed with depression in their lifetime. Among those diagnosed with depression, 66% reported to have ever received treatment for depression. Although individual factors were more important determinants of access to treatment for depression, country-level factors explained 27.6% of the variance in access to diagnosis and 24.1% in access to treatment. Access to treatment for depression improved with increasing country income. Female gender, better education, the presence of physical co-morbidity, more material assets, and living in urban areas were individual level determinants of better access. LIMITATIONS Data on other contextual factors was not available. Unmet need was likely underestimated, since only lifetime treatment data was available. CONCLUSION This study highlights major inequalities in access to a diagnosis and treatment of depression. Unlike the prevalence of depression, where contextual factors have shown to have less importance, a significant proportion of the variance in access to depression care was explained by country-level income.
Administration and Policy in Mental Health | 2018
Ricardo Araya; Pedro Zitko; Niina Markkula
Universal health care programmes have the potential to reduce treatment gaps. We explored the potential impact of an equity-oriented universal health care programme on access to care for depression, hypertension and diabetes using data from two nationally representative health surveys in Chile. The likelihood a depressed individual had accessed health care appears to have increased significantly after the programme was introduced whereas those for hypertension and diabetes remained unchanged. Depressed women seem to have benefited mostly from the programme. Universal health care programmes for depression could substantially increase coverage and reduce inequities in access to health care in middle-income countries.