Epidemiology of SchizophreniaSchizophrenia is a chronic illness that is debilitating to the individuals and families it affects. Although the incidence of schizophrenia is relatively low, schizophrenia is also a major contributor to the global burden of disease. This significant burden arises from two key characteristics, the early onset of the disorder and the large proportion of people who experience persistent or fluctuating disabling symptoms despite treatment. People diagnosed with schizophrenia typically experience a combination of symptoms that can be classified into three broad categories: negative, positive, and cognitive symptoms. Psychotic behaviors not observed in healthy people, such as hallucinations that include hearing voices, delusions, disorganized speech patterns, and abnormal motor behaviors, may be classified as positive symptoms. Negative symptoms are associated with disruptions in what would be considered normal behavior or emotional reactions. These symptoms would include an individual showing a lack of enjoyment in daily life, an ability to efficiently start and complete simple tasks, and projecting a muffled or monotone voice while speaking. Cognitive symptoms are more subtle in their presentation and may include an individual unable to perform simple brain tasks, including the inability to process information or concentrate and pay attention. Although schizophrenia has been the subject of research for decades, its etiology and pathogenesis remain ambiguous. There is a considerable amount of data available regarding the epidemiology of schizophrenia. With the aim of summarizing the large volumes of information into a meaningful and concise context, the results of the studies were aggregated and analyzed...... middle of article ......c review of incidence of schizophrenia: the distribution of rates and the influence of sex, urbanity, migrant status and methodology. BMC Med 2: 13.9. O. Odegaard Emigration and madness Acta Psychiatr. Neurol. Scand. (1932), pp. 1-206 (Suppl. 4)10. Rajji TK, Ismail Z, Mulsant BH. Age of onset and cognition in schizophrenia: meta-analysis. Brother J Psychiatry. 2009;195(4):286-93.11. World Health Organization. The International Statistical Classification of Diseases and Related Health Problems, Ninth Revision (ICD-9) — Section V. Mental and behavioral disorders. World Health Organization, Geneva (1978)12. Wu EQ, Birnbaum HG, Shi L et al. The economic burden of schizophrenia in the United States in 2002. J Clin Psychiatry. 2005;66(9):1122-9.13. Zubin, J. and Spring, B. (1977) Vulnerability: a new view of schizophrenia Journal of Abnormal Psychology 86, 103-126