“I’m a drug addict turned neuroscientist.”What’s it like to swallow 400 milligrams of dextromethorphan hydrobromide, better known as Romilar cough syrup? “Flashes of perception go by like clumps of scenery on either side, while you float along with the slow, irresistible momentum of a dream.” Marc Lewis, a former addict, now a practicing neuroscientist, further muses: “But what was Romilar? It sounded like an ancient kingdom. Would this dark elixir take me to some faraway place? Would it take me into another land? Would it be hard to come back?”
In Memoirs of an Addicted Brain: A Neuroscientist Examines his Former Life on Drugs, Dr. Marc Lewis follows his description of his gateway Romilar drug experience with the neurological basics of the matter: “The problem is that the NMDA receptors in my brain are now clogged with dextromethorphan molecules! The glutamate isn’t getting through. The receptor neurons aren’t firing, or they’re not firing fast enough…. Drugs like DM, ketamine, PCP, angel dust, and those most damaging of substances, glue and gasoline, are called dissociatives, because they do exactly what drugs are supposed to do: they dissociate feeling from reality, meaning from sense—and that’s all they do.”
Speaking of the self-reinforcing cycle “through which calamities of the mind arise from vulnerabilities of the brain,” Lewis argues that dissociatives only produce an absence. As a friend of his puts it with regard to another popular dissociative, “Nitrous oxide doesn’t give you consciousness. It takes it away.” And then, the friend adds: “Just bonk yourself on the head with a baseball bat if you want to lose consciousness.”
Lewis ultimately turns to opioids. “The emotional circuitry of the ventral striatum seems to derive its power from an intimate discourse between opioid liking and dopamine wanting.” In the end, this partnership does more than produce pleasure. It also, Lewis points out, “gets us to work for things.” And by doing that, addictive drugs demonstrate “the fundamental chemistry of learning which really means learning what feels good and how to get more of it. Yet there’s a downside: the slippery slope, the repetition compulsion, that constitutes addiction. In other words, addiction may be a form of learning gone bad. For me, this neurochemical sleight of hand promises much more pain than pleasure in the years to come.”
Lewis does a good job of capturing the feeling of existential despair brought on by uncontrolled addiction: “Contemptible. That’s what I was. Unbelievably stupid, unbelievably irresponsible: selfish, selfish, selfish! But that wasn’t quite it. What described me, what this inner voice accused me of, wasn’t exactly selfish, not exactly weak, but some meridian of self-blame that included both, and also, dirty, disgusting… maybe just BAD.”
How did heroin feel? “I feel relief from that pervasive hiss of wrongness. Every emotional wound, every bruise, every ache in my psyche, the background noise of angst itself, is soaked with a balm of unbelievable potency. There is a ringing stillness. The sense of impending harm, of danger, of attack, both from within and without, is washed away.”
And Lewis provides a memorable summation of the reward system, as dopamine streams from the ventral tegmental area to its targets, “the ventral striatum, where behavior is charged, focused, and released; the orbitofrontal cortex, where it infuses cells devoted to the value of this drug; and the amygdala, whose synapses provide a meeting place for the two most important components of associative memory, imagery and emotion.” In fact, “dopamine-powered desperation can change the brain forever, because its message of intense wanting narrows the field of synaptic change, focusing it like a powerful microscope on one particular reward. Whether in the service of food or heroin, love or gambling, dopamine forms a rut, a line of footprints in the neural flesh.”
And, of course, Lewis relapses, and eventually ends his addictive years in an amphetamine-induced psychosis, committing serial burglaries to fund his habit. “You’d think that getting busted, put on probation, kicked out of graduate school, and enduring a kind of infamy that was agonizing to experience and difficult to hide—all of that, an the need to start life over again—would be enough to get me to stop. It wasn’t.”
Not then, anyway. But Lewis has been clean now for 30 years. “Nobody likes an addict,” he writes. “Not even other addicts.”
If drugs are such feel-good engines, what goes wrong? Something big. “Because when drugs (or booze, sex, or gambling) are nowhere to be found, when the horizon is empty of their promise, the humming motor of the orbitofrontal cortex sputters to a halt. Orbitofrontal cells go dormant and dopamine just stops. Like a religious fundamentalist, the addict’s brain has only two stable states: rapture and disinterest. Addictive drugs convert the brain to recognize only one face of God, to thrill to only one suitor.” The addict’s world narrows. Dopamine becomes “specialized, stilted, inaccessible through the ordinary pleasures and pursuits of life, but gushing suddenly when anything associated with the drug comes into awareness…. I wish this were just an exercise in biological reductionism, or neuro-scientific chauvinism, but it’s not. It’s the way things really work.”
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