19902
The cause of serotonin deficiency in depression was attributed to the shunt of TRP " metabolism away from serotonin production towards KYN production " due to cortisol - induced activation of liver enzyme , tryptophan 2 , 3 - dioxygenase , the rate - limiting enzyme of TRP - KYN pathway .
 Chemical: serotonin; Chemical: TRP; Chemical: serotonin; Chemical: KYN; Chemical: cortisol; Chemical: tryptophan; Chemical: TRP; Chemical: KYN
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: TRP; Chemical: serotonin; Chemical: KYN; Chemical: cortisol; Chemical: tryptophan; Chemical: TRP; Chemical: KYN