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Nowadays the most widely used antidepressants are selective serotonin reuptake inhibitors ( SSRI ) or noradrenaline reuptake inhibitors ( NRI ) , however , these take four to eight weeks to exert their effects and each drug is efficacious only in 60 - 70 % of patients .
 Chemical: serotonin; Chemical: noradrenaline
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: serotonin; Chemical: noradrenaline