A disorder of choice

This blog post expressing skepticism about addiction as a brain disease was recently brought to my attention.

He lays out A pro-disease argument as THE pro-disease argument:

What do gambling, sex, heroin and cocaine — and the other things that can addict us — have in common?

One strategy is to look not to the substances and activities themselves, but to the effects that they produce in addicts. And here neuroscience has delivered important insights.

If you feed an electrical wire through a rat’s skull and onto to a short dopamine release circuit that connects the VTA (ventral tegmental area) and the nucleus accumbens, and if you attach that wire to a lever-press, the rat will self-stimulate — press the lever to produce the increase in dopamine — and it will do so basically foreover, forgoing food, sex, water and exercise. Addiction, it would seem, is produced by direct action on the brain!

(See here for a useful Wikipedia review of this literature.)

And indeed, there is now a substantial body of evidence supporting the claim that all drugs or activities of abuse (as we can call them), have precisely this kind of effect on this dopamine neurochemical circuit.

“all..have precisely this kind of effect”? Who has asserted that? (This is import, he uses it against the disease model.)

These studies do, however, offer a stunning  demonstration of the power of a malfunctioning pleasure circuit. Noe’s reaction? Meh. We all have a reward pathway.

Neuroscientists refer to the system in question as the “reward-reinforcement pathway” precisely because all rewarding activities, including nonaddictive ones like reading the comics on sunday morning or fixing the leaky pipe in the basement, modulate its activity.

As an indicator of a disease, he presents the effect of a malfunctioning VTA as binary. If the addict is sometimes able to choose something else over the drug, we’re not like that rat and it must not be a disease.

So, because the drug’s domination is not total, we treat this experience described in the NYT as though it has the same basis as the experience of non-addicts?

“Cocaine reconnected my mind to my body, and I felt tremendously alive, hypersexual and hopeful once again,” he wrote. “At least I had a new God to believe in, even if I knew all along this was a false God, a deceitful God, one who always promised misery and defeat. So, I choose this God of intense extremes over the monotony of everyday life.”

The other big problem I have with this is that there is no mention of the memory circuits or the frontal cortex. No one says that addiction is explained by the reward pathway. No one claims that the course, severity and treatment response of addiction are not influenced by factors outside the brain or outside the person.

A few other thoughts.

It’s worth noting that Gene Heyman repeatedly points to 2 things as primary evidence that addictive drug use is not involuntary. Narratives from addicts about hitting bottom and choosing to recover and epidemiological data showing large numbers of substance dependent people experiencing spontaneous remission or natural recovery.

Narratives from addicts demonstrate that choosing recovery is necessarily for recovery. So? Choosing to quit is necessary but not sufficient. How many addicts choose to quit and are unable to? Why is this ignored?

As for the people who experience spontaneous remission, what are the other possible explanations?

• Maybe our diagnostic tools are crude and capture false positives. Maybe those with these false positives are likely to moderate or quit on their own.
• Or, maybe there is a spectrum of severity and those with the less severe forms moderate or quit on their own.
• Or, maybe its course varies. Would this be incompatible with it being a disease?
• Or, maybe there are several neurological mechanisms (reward pathway, memory circuits, risk evaluation, self-regulation, stress responses, etc.) and some people may have 2, others may have 6.  Some factors may be associated with a more chronic form, others may be associated with a more severe loss of control and overall severity may be associated with the number of factors the person has. (Some might be primary to addiction, others secondary.)