<prompt> Translate the following text to EnglishUpjohn anasema kuwa sababu ya kuachana na dawa hiyo ni kwamba hairudishi tamaa ya ngono au furaha ambayo walikuwa nayo wakati mmoja.  <response>: According to Upjohn, the leading explanation offered by the quitters is that the drug doesnt restore the sexual desire or the pleasure they once derived from sex. 