There are many environmental factors that have been linked to schizophrenia, pre- and post-natal, including exposure to rubella, bereavement during pregnancy, and obstetric CNS damage.[Sullivan, 2005; Dean & Murray, 2005] It is unclear what the general impact of some of these factors is, and indeed how the risk factors may combine.
Whilst the factors outlined in the graph on the slide focus on pre- and post-natal risks for schizophrenia,[Sullivan, 2005] there are some risks of later life that have been identified as well.[Dean & Murray, 2005] These factors include drug use, migration, urbanicity, life events, and social adversity (e.g., social class, unemployment, and being single).[Dean & Murray, 2005]
For a person with a positive family history of schizophrenia, the odds ratio of developing schizophrenia is approximately 10 – greater than any of the individual risk factors outlined on the slide.[Sullivan, 2005] Schizophrenia should be conceptualised as a complex condition arising both from genetic and environmental influences.[Sullivan, 2005; Dean & Murray, 2005; Lakhan & Vieira, 2009] The role of genetics in schizophrenia will be explored in some detail later in this slide deck.
References:
Dean K, Murray RM. Environmental risk factors for psychosis. Dialogues Clin Neurosci 2005; 7 (1): 69–80.
Lakhan SE, Vieira KF. Schizophrenia pathophysiology: are we any closer to a complete model? Ann Gen Psychiatry 2009; 8: 12.
Sullivan PF. The genetics of schizophrenia. PLoS Med 2005; 2 (7): e212.