22696
Furthermore , these data point to the potential connection between the serotonergic system and MCH in sleep regulation , which can be relevant in depression and in other mood disorders .
 None
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities:  
Answer:
 None