This strik­ing image of hur­ri­cane Katrina sur­vivors risk­ing drown­ing to load them­selves down with beer and cig­a­rettes illus­trates a remark­able fea­ture of human decision-making. We can become extra­or­di­nar­i­ly moti­vat­ed to seek out and con­sume psy­choac­tive sub­stances. Nicotine, alco­hol, hero­in, cocaine, amphet­a­mines, and the like.

A man in chest-deep water pulling along a makeshift raft with a woman on it surrounded by some supplies, though mostly cans of beer.

Darwin might’ve been flum­moxed by this. How did our species sur­vive when our sur­vival instincts can be cast aside in favor of drugs that kill us? Well, the answer’s two-fold. First, neu­ro­science research reveals that the drugs that addict us work on pre­cise­ly the same brain sys­tems as nor­mal­ly guide our sur­vival deci­sions. Second, only in the mod­ern era of indus­tri­al glob­al cap­i­tal­ism was psy­choac­tive sub­stance expo­sure near­ly universal. 

A fac­to­ry work­er in the 1800s could roll maybe five hun­dred cig­a­rettes a day. A mod­ern cig­a­rette rolling machine can pro­duce twen­ty thou­sand per minute. And mod­ern trans­porta­tion sys­tems can deliv­er those cig­a­rettes to every city and town all over the world. 

These two com­bined real­i­ties, our evo­lu­tion­ar­i­ly con­served vul­ner­a­bil­i­ty to addic­tion, and the devel­op­ment of the pro­duc­tion and trans­porta­tion sys­tems that can deliv­er sen­tences world­wide, is why one in six deaths on the plane and among adults is attrib­ut­able to psy­choac­tive sub­stance use. And this pro­por­tion is like­ly to rise in the future.

Primate research indi­cates that there may be a polit­i­cal and eco­nom­ic dimen­sion to this. When low­er pri­mates form a hier­ar­chy, those at the bot­tom under­go a change in their dopamine sys­tem. This makes them more like­ly to con­sume drugs in an addic­tive fash­ion. Now, if this turns out to be true of our species, that would mean that human beings are par­tic­u­lar­ly vul­ner­a­ble if they’re in some way dom­i­nat­ed or don’t have any power.

Luis Felipe Salas, "Poverty"

Luis Felipe Salas, Poverty”

Now, addic­tion could hap­pen to any­one at any lev­el soci­ety, but if you look in wealthy soci­eties, peo­ple who have less eco­nom­ic and edu­ca­tion­al resources are more prone to addic­tion. So as inequal­i­ty wors­ens, we real­ly have a risk of cre­at­ing a dis­em­pow­ered under­class of peo­ple who are lit­er­al­ly sedat­ed by ever more avail­able psy­choac­tive substances. 

Our Stanford University team is going after this prob­lem in two main ways. First, we’re using the tools of neu­ro­science to unrav­el the basic mech­a­nisms of addic­tion in the brain. This includes imag­ing stud­ies where we try to pre­dict whether or not patients in treat­ment will relapse. If we had a reli­able sig­nal of who need­ed more care, we could then tai­lor treat­ment and help more peo­ple recover.

We also work direct­ly with nation­al and inter­na­tion­al pub­lic pol­i­cy­mak­ers. For exam­ple, peo­ple who reg­u­late the tobac­co, alco­hol, and phar­ma­ceu­ti­cal indus­try, and those who over­see the health­care sys­tem and the crim­i­nal jus­tice sys­tem. We com­mu­ni­cate to our friends in the pol­i­cy world what sci­ence has to teach about addic­tion and how you can use that infor­ma­tion to make poli­cies that do a bet­ter job pro­tect­ing peo­ple and pro­mot­ing pub­lic health.

One of our key mes­sages is that psy­choac­tive sub­stances are not ordi­nary com­modi­ties. With many things that are for sale you can assume that what­ev­er peo­ple con­sume reveals their ratio­nal pref­er­ences. So if you just dereg­u­late it’ll all aggre­gate up to a pub­lic good. That’s prob­a­bly true for broc­coli. But it’s not true for psy­choac­tive sub­stances, because they impair our brain’s abil­i­ty to val­ue things.

That’s why any poli­cies in this area have to take into account evo­lu­tion­ar­i­ly con­served cir­cuits and func­tions in the brain. Prevention pro­grams the tell teenage boys that if you smoke you might get lung can­cer in thir­ty years don’t work. Prevention pro­grams that tell them that girls don’t like to kiss smok­ers make them go pale with fear.

Think of anoth­er prob­lem. People who drink and dri­ve over and over again. What most gov­ern­ments do is they threat­en them. They say you know, Someday you’re going to have an acci­dent and we’ll send you to prison for a long time.” Now faced between the choice between a swift and cer­tain reward from drink­ing and a dis­tant prob­a­bilis­tic cost, most peo­ple do what evo­lu­tion teach­es them to do. They eat their dessert first, and they go on drinking.

But imag­ine a dif­fer­ent approach that is tai­lored to the real­i­ties of the human brain. This is what’s being done in the US state of South Dakota: People who are con­vict­ed of drunk dri­ving mul­ti­ple times are sen­tenced not to be allowed to drink. And this is backed up by mul­ti­ple breath tests every sin­gle day. Those peo­ple who are on this pro­gram and then are caught drink­ing are giv­en the kind of con­se­quence to which our brain is attuned, some­thing swift and cer­tain. The con­se­quence is mod­est. Twelve hours, twenty-four hours in a jail cell. But because it’s swift and it’s cer­tain, it’s high­ly moti­vat­ing for peo­ple to change their behavior.

After over eight mil­lion sched­uled tests, the rate at which peo­ple show up and have a neg­a­tive test (mean­ing they’ve not been drink­ing) is over 99%. This pro­gram has evi­dence of reduc­ing drink dri­ving arrests, domes­tic vio­lence arrest, and pop­u­la­tion mor­tal­i­ty. But it’s just one exam­ple of a gen­er­al prin­ci­ple. We can use what we’re learn­ing in sci­ence to make poli­cies towards addic­tion that pro­tect the pub­lic, that improve pub­lic health, and most impor­tant­ly, too, they also help the per­son that has the addiction.

The mag­nif­i­cent decision-making organ that evo­lu­tion has bequeathed us is vul­ner­a­ble to addic­tion. Perhaps par­tic­u­lar­ly if we live in the low­er tiers of soci­ety. This cre­ates a risk for human­i­ty. Karl Marx was wor­ried that reli­gion would become the opi­ate of the mass­es. But if we don’t use neu­ro­science to make bet­ter treat­ments and bet­ter poli­cies regard­ing addic­tion, the opi­ate of the mass­es will be opiates.

Further Reference

Keith Humphrey’s fac­ul­ty pro­file at the Stanford Medicine site.