I could be wrong, but I think I did read that over time as the addict uses he loses a chemical called dopamine that helps them feel emotions...and this chemical does not regenerate in the brain, thus leaving the addict with difficulty expressing some emotions as time goes on. I'm living proof because abf has often seemed to have absolutely no remorse for things he has said or done to hurt me, none whatsover even after I asked for an apology...the blame was often shifted to me........I really think he is dopamine depleted to some extent.