Is ecstacy addictive ?

so my girlfriend took half a pill of esctacy about a month ago in a rave .. she said it was one of the best experiences in her life ... and since then she cnt seem to stop talkin abt it and she's planning on taking it again in abt a month .. i advised her not to .. i mean she kinda seem addicted to me .. and if she takes more .. shes goin to get more into it .. what do you guys think abt the whole subject ?? i know esctacy is not physically addictive ,, but psychologically it kinda seems to be ..