Not necessarily. In the beginning before it became obvious via rapid weight loss, extreme mood shifts and before my father found out I was dabbling in heroin yes, but ultimately I admitted it to my parents, got on methadone and then kicked.
I havent told them I've relapsed and considering I'm kicking I dont feel a need, however the second I'm asked 'Are you using heroin again?' my response will be the truth.
I'm quite open about drug use in general, though - despite having told some 'friends' in the past and suddenly never hearing from them again afterwards. I dont believe them to be true friends, however.