Everyone who lifts for reasons beyond health, i.e to bodybuild, are doing so to compensate for personal inadequacies and insecurities. Derek is clearly at the extreme end of this spectrum, he obviously has some deep seeded psychological issues and his only way of trying to deal with them is to portray himself as this uber Alpha, hard guy. It's sad that his inability to accept who he is drives him to continuous self destruction and a hugely shortened lifespan.