30082
RATIONALE : Selective serotonin reuptake inhibitors ( SSRIs ) , in addition to being able to enhance serotonergic neurotransmission , are able to modulate other brain systems involved in depression .
 serotonin
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 serotonin