Eleven days after his sister thought he was doing well, he was using again. She says he chose it. He says that his shift moved to nights in April, that the pharmacy switched him to a generic that did not sit right, that his ride on Thursdays fell through twice, and that by the second week he was sleeping four hours a night and had not spoken to anybody in nine days.
This is an argument they've had four times in six years. Neither can repeat the other's version back.
All of this is invented. Putting the argument on made-up people means I am not describing anybody's family, and we're looking at the general shape of recovery.
Most people on both sides of that argument believe the same thing. That settling what caused the addiction will settle how much the man gets blamed.
Here is what the evidence supports. When researchers pooled the experiments on what a brain explanation does to the way people judge somebody, three things moved and all of them the wrong way. Readers wanted more distance from the person described, judged him more dangerous, and were less hopeful about his recovery. Blame is the one result that could not be pinned down, because the range around it covers a large drop, no movement, and a small rise. Changing one word in a case description, from substance abuser to person with a substance use disorder, did move blame among 516 clinicians.
Four arguments in six years that settle nothing is the visible cost. The third question underneath the other two, about what is owed to him regardless of what caused any of it, is the one neither of them has named. It is getting answered anyway. It gets answered by who stops calling, who stops lending money, and who keeps the spare room made up. Nobody decided that, and it got decided.
The sister and brother are arguing about cause. There are two ways people try to move an argument like that. You can tell somebody a different story about what caused it. Or you can change what you call the man.
The disease argument
The reason anyone fights about whether addiction is a disease is that the frame is supposed to move the attribution off character, onto biology, and therefore off blame. People make that argument in good faith, usually because they have watched somebody they love get treated badly by somebody who thought it was a character problem.
Underneath sits a scientific dispute that is unresolved. One camp holds that addiction is an acquired disease of the brain and that the disease model has produced better treatment. Another camp holds that the evidence does not support the disease model to the extent its advocates claim. Marc Lewis makes the sharpest version of the second case: addiction does change the brain, and brains are supposed to change, they are built to change, so the disease finding does less work than it looks like it does.
That fight is not settled here. A narrower question is whether framing does to blame what its defenders say it does, and that one has evidence.
The brain story
One distinction before the evidence, because it decides how much of the evidence applies. The studies below tested a causal story about brains. That is not the same thing as calling addiction a disease. A person can call addiction a disease without saying a word about brains, and Marc Lewis says a great deal about brains while denying it is a disease. So, the evidence is narrower than the argument it gets used in.
What the brain story does
Here is what the advocates expect. Tell people that a mental health problem comes from the brain, and they will stop treating it as weak will or bad character. Blame goes down.
There is a more careful version of the same hope, called the mixed-blessings model. Blame still goes down, because the trouble now belongs to something the person cannot control. But a second thing happens at the same time. People start to think of the person as carrying a fixed abnormality, something deep and permanent, and they pull away. Blame down, fear up.
In 2018 two researchers pooled every study they could find on what a brain explanation does to the way people judge somebody and ran the numbers.
The experiments did not establish a direction for blame. The estimate came out slightly on the good side and the range around it covers a large drop, no movement, and a small rise, which is a different result from blame holding still.
Everything else moved and moved the wrong way. Readers who got the brain explanation wanted to keep more distance from the person described. They judged that person more dangerous. They were less hopeful about recovery.
So, the plain hope is unsupported on the one outcome it cares most about, and the careful version got its second prediction confirmed.
Why the blame result is the shaky one
Three of those findings are solid: distance, danger and hopelessness. The blame finding is not.
The researchers report each result as a single number, where zero means the two groups came out the same. Distance, danger and hopelessness all came in around a quarter of a point on the bad side. The uncertainty around each of them stayed on the bad side too.
Blame came in at a quarter of a point on the good side. But the range around it runs from three quarters of a point better all the way to a quarter of a point worse. Zero sits inside that range.
So, blame may have dropped a great deal, or not moved, or risen slightly. This evidence cannot tell you which. That is different from finding that blame holds still. The same result turns up when an effect is real and the studies are too small to catch it.
One more limit, and it is a large one. Not one of these experiments was about addiction. They were about depression, panic disorder, psychopathy, and mental illness in general. The authors say they had too few studies of any single condition to check whether the pattern changes by diagnosis. Carrying the pattern over to addiction is my move and not theirs, and if addiction turns out to behave differently, that is an interesting question in itself.
The one study about addiction
Researchers showed 755 people a short case description, picked at random from eight versions: four conditions, alcohol use disorder, opioid use disorder, problem gambling, or diabetes, each written with a man or a woman. Then they asked what each reader believed causes addiction, and what each reader thought of the person described.
Believing addiction is a disease made no difference to how readers judged the person with alcohol use disorder, and none to how they judged the person with opioid use disorder. For the gambler, disease belief made things worse. That was the only place disease belief mattered at all.
Believing addiction is a moral failing made things worse everywhere, strongly, every time.
One caution about what this study can support. The four descriptions were assigned at random, but nobody assigned anybody a belief. The researchers found the belief and the judgment sitting together in the same readers. Nothing here shows that changing a reader's belief would change that reader's judgment.
What you call him
Kelly and Westerhoff gave 516 clinicians the same short description of a man in legal trouble over alcohol and drugs, and changed one word. Half of them read that he was a substance abuser. Half read that he had a substance use disorder. Nobody saw both, and two thirds of the room held doctorates.
The clinicians who read abuser held the man more responsible for his situation and were readier to see him punished.
Nothing else moved. The two groups did not differ on whether the man was a threat, or on whether he should be treated instead of punished.
A second study put the same two phrases to 314 members of the public and got the same result on responsibility, plus the threat difference the clinicians did not show. That study showed each person both versions in turn, which is the weaker way to run it, because seeing both invites you to work out what is being tested.
I cannot tell you how big either effect was. Neither paper gives a figure I could get to, and the full text of the clinician study is behind a paywall. Direction is all I am claiming. If somebody tells you one word transforms clinical judgment, that is more than these two papers will carry.
Explaining and naming are not the same lever
Telling people the trouble comes from the brain did not move blame. Calling the man an abuser did.
Explaining and naming are two different acts, and it is easy to file them together, because both are things you say about somebody. But one is a claim about where the trouble came from, and the other is a name for the person who has it.
These are separate literatures with separate designs and separate populations, so nobody ran the two against each other. What can be said is what each one found. In the brain-explanation experiments, blame was not resolved. In the terminology experiments, the label changed how responsible the clinicians held the man.
People who fight about whether addiction is a disease are arguing about where the trouble came from. Arguing about where the trouble came from did not move blame.
In the kitchen
The sister and brother are arguing three things at once. Whether the brain changes count as a disease, which no measurement settles. What a given frame does to how he gets treated, which has been measured. And what is owed to him no matter what caused it, which no measurement touches.
They do not disagree about the eleven days. In four conversations neither of them has said which question they are having.
So, name the question. Before the next round, say whether you are arguing about whether addiction is a disease, about what the words do to how he gets treated, or about what you owe him regardless. The first two are empirical and can be argued with evidence. The third is not, and no measurement of any kind settles what one person owes another. That is usually the argument you are actually having.