devastated the addiction community. what addiction is in your brain is down regulation of dopamine, and what social interaction does is up regulate dopamine. it is organic medicine for the recovering brain. reporter: add to the mix cheap and plentiful fentanyl, 50 to 100 times more potent than morphine, whether in pill or wow durr f powder form. how did fentanyl come into your life? first overdose. how many overdoses has there been? 14. reporter: he was clean 19 months, then his grandfather died. grief drove him to relapse. he thought he was using heroin. it was fentanyl. i used less than 1/10th gram. less than 1/10th? it was straight fentanyl. that is a tiny that s tinier than tiny. it is barely a sprinkle of salt.