6778
Behavioral studies of chronic CB ( 1 ) receptor activation may provide a pharmacological approach to understanding efficacy - related differences among CB ( 1 ) ligands as well as mechanistic commonalities between cannabinoid and noncannabinoid drugs .
 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