26698
RATIONALE : Although a number of studies investigated the link between major depressive disorder ( MDD ) and metabolic syndrome ( MetS ) , the association between MetS and treatment - resistant depression ( TRD ) is still not clear .
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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:
 None