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Schizophrenia is a devastating neurodevelopmental disorder that , despite extensive research , still poses a considerable challenge to attempts to unravel its heterogeneity , and the complex biochemical mechanisms by which it arises .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
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