Why do opioids make people self-destructive?

We witnessed a tragedy last night, which is all too common in the fight against opioid addiction. Loving parents attempted to deliver their son to the MATClinics Towson office for a last ditch effort at treatment. They have spent the last 5+ years moving him from one treatment center to another across the US, spending all of their available financial resources.  They were able to get their son to our parking lot, but he refused to come upstairs to see the Doctor.   We sent down one of our case managers, who together with the parents, were able to convince him to at least have a quick talk with the Doctor.

No luck.  After less than ten minutes, prospective patient and Doctor walked out of the office. The patient walked out the front door and the Doctor just shook his head.  The patient refused treatment. For years, his parents, endless counselors, physicians and staff, have told him that if he does not find and stick to a recovery regimen, he will die.  

He says he understands the risk and the likely outcome.  He does not want treatment.  He does not want anything other than to consume more heroin.

We went to bed last night grieving for the parents and for the son.  What is it about opioids that make people behave this way?  Why are they willing to sacrifice everything for one more hit?

The best description that I have seen of the grip opioids have on people was in the Sam Quinones' book Dreamland.  It describes the morphine molecule, the starting point for all opioids, as brainwashing humans:

. . . pushing them to act contrary to their self interest in pursuit of the molecule.  Addicts betray loved ones, steal, live under freeways in harsh weather, and run similarly horrific risks to use the molecule.
— Dreamland (Quinones, 2015)

Some addicts would argue with this.  Our prospective patient last night argued that he is happy with his life as an addict.  He likes heroin, he makes decent money dealing, and he has no interest in changing his life.   That it pains and terrifies his parents is not enough for him to change his life.

What's happening?   Is it a rational choice to keep living the life he is living or is it as Quinones says above, that he is essentially a hostage to the molecule.  We are conditioned to believe that adults can make rational decisions, that they will choose to do what best suits them.

The science around addiction, however, is clear that long-term use of opioids changes the brain. It not only creates overwhelming physical and emotional cravings, it also changes the way your brain is conditioned to find pleasure.  These are incredibly powerful forces, that are physical.  Its not as simple as "choosing" to stay an addict.

So what is the right way to think about these kinds of behaviors?  I'll leave that to another post.