2564
Compared with present ecstasy users , the past users showed no change for ten measures , increased impairment for two measures , and improvement on just one measure .
 Chemical: ecstasy
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 Chemical: ecstasy