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Environmental factors, including cannabis, are strongly related to the age of onset and morbidity of schizophrenia
  1. Vishal Bhavsar
  1. Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, UK;

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ABSTRACT FROM: Stepniak B, Papiol S, Hammer C, et al. Accumulated environmental risk determining age at schizophrenia onset: a deep phenotyping-based study. Lancet Psychiatry 2014;1:444–53.

What is already known on this topic

Psychosis is causally related to genetic makeup, in interaction with environmental factors, such as adversity and cannabis misuse.1 Identifying the factors in the population that need to be tackled in order to reduce disease occurrence is important. However, understanding how these different factors combine together and determine the risk of schizophrenia and prognostic outcomes requires larger studies that could be crucial in stratifying patients into different treatment pathways.

Methods of the study

This study assesses the association between known risk factors for schizophrenia (genotypic markers, cannabis, urban residence and birth, psychological trauma, perinatal brain insult and migration) with a group of important variables (age of onset and prodrome, symptom expression and socioeconomic status). The analysed data set contained 750 male patients with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) schizophrenia from the Gottingen Research Association …

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  • Competing interests None declared.