Want to know how the opioid crisis started? This video offers just the right explanation. Reviewing the opioid tolerance and cAMP theory, it talks about the overprescription crisis of opioids. Timeline: 00:25 introduction 03:05 tolerance and cAMP theory 06:08 withdrawal symptoms 09:03 summary of the progression 09:57 how it affects breathing? 11:20 naloxone 12:20 over the prescription crisis