Changing Memories to Treat PTSD

A controversial area of brain research suggests it may be possible””but is it ethical?

National Journal
Aug. 28, 2014, 12:46 p.m.

Be­fore he lost the abil­ity to sleep through the night; be­fore the pan­ic at­tacks star­ted; be­fore he drove his truck over an im­pro­vised ex­plos­ive device, leav­ing him with trau­mat­ic brain in­jury; be­fore a second road­side bomb did the same thing a few weeks later””be­fore all of that, on the U.S. mil­it­ary base near Kanda­har, Afgh­anistan, sol­dier Kev­in Mar­tin liked to think about the sci­ence-fic­tion movie In­cep­tion.

“My friends and I used to joke dur­ing our time in Afgh­anistan that we were go­ing to take all the money we had and pay someone to Incept us,” he says””ref­er­en­cing the film’s premise of im­plant­ing or ex­tract­ing in­form­a­tion from a per­son’s mind as they sleep”””so that we could put a cool­er, not-as-bad memory of Afgh­anistan in our brains and go on with the rest of our lives.”

Thus far, no such treat­ment ex­ists for Mar­tin, 23, who re­turned to the U.S. in 2012 and was dia­gnosed with post-trau­mat­ic stress dis­order earli­er this year. Now a sopho­more at Trin­ity Col­lege, he’s con­sidered 30 per­cent dis­abled by the Vet­er­ans Af­fairs De­part­ment for his PTSD (he’s also 10 per­cent dis­abled for an un­re­lated shoulder in­jury) and takes pre­scrip­tion an­ti­anxi­ety med­ic­a­tion to ease his symp­toms.

But re­search­ers have be­gun to in­vest­ig­ate a pos­sible treat­ment sim­il­ar to the one Mar­tin ima­gined: A pa­per re­cently pub­lished in the journ­al Bio­lo­gic­al Psy­chi­atry ar­gues that it may be pos­sible to treat PTSD by al­ter­ing pa­tients’ memor­ies.

The pa­per re­views a grow­ing body of sci­entif­ic lit­er­at­ure on memory re­con­sol­id­a­tion, a re­l­at­ively new (and, in hu­mans, still some­what con­ten­tious) concept in which old in­form­a­tion is called to mind, mod­i­fied with the help of drugs or be­ha­vi­or­al in­ter­ven­tions, and then re-stored with new in­form­a­tion in­cor­por­ated””like a piece of met­al that’s been melted down, re­mol­ded, and left to harden in­to a dif­fer­ent shape.

Though dif­fer­ent types of memor­ies are so­lid­i­fied in dif­fer­ent ways””the fear-driv­en memory of driv­ing over a bomb, for ex­ample, will make its way through the brain dif­fer­ently than a mundane memory of yes­ter­day’s break­fast””there are gen­er­al neur­o­lo­gic­al pro­cesses that all memor­ies fol­low.

“In memory re­search, we talk about three parts,” ex­plains Ken Paller, dir­ect­or of the cog­nit­ive neur­os­cience pro­gram at North­west­ern Uni­versity. “The first part is the ac­quis­i­tion or cod­ing of a memory,” in which our brains pro­cess the in­form­a­tion our senses are send­ing, “and the last part is re­triev­ing a memory. And in between, we talk about con­sol­id­a­tion,” the pro­cess by which sens­ory in­form­a­tion””a sight, a taste””so­lid­i­fies in­to fully formed memor­ies to be stored for the long term.

Typ­ic­ally, the more of­ten memor­ies are re­called, the stronger they be­come. “If you’re try­ing to mem­or­ize something in a book, you sit there and re­peat it over and over,” ex­plains Wendy Su­zuki, a re­search­er at New York Uni­versity’s Cen­ter for Neur­al Sci­ence. “That’s also an ex­ample of how things get con­sol­id­ated. You re­peat [them] over and over.”

But with re­con­sol­id­a­tion, the re­search­ers ex­plain, con­sciously re­call­ing a memory is also what al­lows it to be ma­nip­u­lated. “[Memor­ies] are not ne­ces­sar­ily fixed but can be changed long after stor­age,” they write. “Seem­ingly stable memor­ies may re-enter an un­stable state when they are re­trieved, from which they must be re-sta­bil­ized.”¦ Dur­ing re­con­sol­id­a­tion, memor­ies are sus­cept­ible to modi­fic­a­tion again.”

“Do you lose some part of your­self if you get rid of a pain­ful memory? Would that be worth the trade?”

One way is by dis­tract­ing the brain as it re­calls, or “ac­tiv­ates,” memor­ies: People who were asked to mem­or­ize two sep­ar­ate lists of ob­jects, for ex­ample, did worse on the second list after they were re­minded of con­tent from the first, while people who were asked to mem­or­ize a folk tale be­fore re­call­ing auto­bi­o­graph­ic­al events de­scribed their memor­ies in less de­tail than those who had not seen the story.

Per­haps more com­pel­ling for the treat­ment of PTSD, though, are the ex­per­i­ments that in­volve tam­per­ing with fear-driv­en memor­ies us­ing phar­ma­ceut­ic­als. In one study, pub­lished in Nature Neur­os­cience, vo­lun­teers were stim­u­lated to gen­er­ate fear memor­ies after be­ing sub­jec­ted to loud noises and im­ages of spiders; later on, one group was giv­en pro­p­ran­o­lol (a beta-block­er used to slow heart­beat and some­times used in the treat­ment of anxi­ety dis­orders) be­fore be­ing made to re­call the fear­ful ex­per­i­ence, while the oth­er was giv­en placebo pills. When the two groups were again re­minded of the memory days after the ex­per­i­ment began, those who had taken the pro­p­ran­o­lol showed markedly less fear than those who had not.

A study from the journ­al Psy­cho­neur­oen­do­crino­logy found a sim­il­ar ef­fect with pro­p­ran­o­lol in sub­jects who were asked to ima­gine a fear­some event that hadn’t ac­tu­ally happened””when they were made to re­call the ima­gined scen­ario, the chem­ic­al eased their re­sponse much as it had done in ex­per­i­ments with real fear memor­ies. (People with PTSD, it bears not­ing, can ex­hib­it symp­toms of the dis­order even if it was someone close to them who ac­tu­ally ex­per­i­enced the trauma; journ­al­ists fre­quently ex­posed to vi­ol­ent im­ages can de­vel­op PTSD even from the safety of their news­rooms.)

Com­pared to Mar­tin’s hy­po­thet­ic­al In­cep­tion scen­ario, the types of modi­fic­a­tion dis­cussed in the re­search re­view are de­cidedly less dra­mat­ic. Based on the stud­ies presen­ted, re­con­sol­id­a­tion ap­pears to be much less heavy-handed than its sci­ence-fic­tion ana­logue””a lessen­ing of the emo­tions as­so­ci­ated with the memory or the dulling of its de­tails, rather than the total men­tal erad­ic­a­tion of an event or the cre­ation of a new one from scratch.

But still, the idea of re­con­sol­id­a­tion broaches new ter­rit­ory for pos­sible re­lief from PTSD, which af­fects an es­tim­ated 7 to 8 per­cent of Amer­ic­ans, by ad­dress­ing its root cause rather than its symp­toms. Cog­nit­ive pro­cessing ther­apy and ex­pos­ure ther­apy, two com­mon be­ha­vi­or­al treat­ments, fo­cus on cop­ing skills and con­trolling fear, and ac­cord­ing to the Na­tion­al In­sti­tutes of Men­tal Health, only two med­ic­a­tions“”the an­ti­de­press­ants Zo­loft and Pax­il””are cur­rently ap­proved by the U.S. Food and Drug Ad­min­is­tra­tion ex­pli­citly for the treat­ment of PTSD, though oth­er an­ti­de­press­ants and anti-anxi­ety med­ic­a­tions are of­ten pre­scribed to treat the emo­tion­al ef­fects char­ac­ter­ist­ic of the con­di­tion.

“The nat­ur­al in the realm of memory does in­volve re­shap­ing and for­get­ting. Maybe the in­jury is more like the un­nat­ur­al.”

Some psy­cho­lo­gists, however, re­main skep­tic­al that this par­tic­u­lar area of memory re­search is the an­swer.

Des­pite the find­ings of some of the stud­ies ad­dressed in the Bio­lo­gic­al Psy­chi­atry re­view, the bulk of the re­search on re­con­sol­id­a­tion thus far has in­volved lab an­im­als rather than hu­mans, ex­plains Paul Re­ber, dir­ect­or of North­west­ern Uni­versity’s Brain, Be­ha­vi­or, and Cog­ni­tion pro­gram””and map­ping ro­dent brains doesn’t provide ad­equate in­sight to the in­tric­ate, messy work­ings of hu­man memory, where something as seem­ingly in­con­sequen­tial as a smell or a snip­pet of mu­sic can pull for­ward a rush of emo­tions from events past.

“In an­im­al stud­ies, you have the greatest con­trol over the neur­al sys­tems, but you don’t have any ac­cess to the sub­ject­ive ex­per­i­ence of memory,” he says. “So you can build mod­els of things you think might be re­lated to what hu­mans ex­per­i­ence with PTSD, but you don’t really know how they’re con­nec­ted.”

Paller, too, ques­tions the faith that some have placed in re­con­sol­id­a­tion, ar­guing that it stems from an over­sim­pli­fied un­der­stand­ing of the way that memor­ies are pro­cessed in the first place. Rather than something that must be de-sta­bil­ized in or­der to change, a memory is a con­stantly shift­ing en­tity, con­tinu­ally up­dated with new con­text even when it isn’t be­ing con­sciously re­called.

“It’s a lot dif­fer­ent than when you put some in­form­a­tion in your com­puter and just ex­pect to get that out in the same form,” he ex­plains. “If you learn something on a Wed­nes­day and you learn new in­form­a­tion the next day, that can change the memory that you stored. So every time that we learn something, sub­sequent events can col­or it dif­fer­ently.”

“The more soph­ist­ic­ated view of con­sol­id­a­tion is, [it] can strengthen a memory, but it doesn’t reach a per­man­ent stage ever,” he says.

Wheth­er or not re­con­sol­id­a­tion is a vi­able pos­sib­il­ity for PTSD treat­ment may still be up for de­bate; wheth­er or not it should be a pos­sib­il­ity, though, is an­oth­er ques­tion al­to­geth­er.

Slip­pery philo­soph­ic­al quandar­ies abound: Does the act of tak­ing a pill to change memory re­quire dif­fer­ent eth­ic­al con­sid­er­a­tions than something like psy­cho­ther­apy or hyp­not­ism? Could it pave the way for more omin­ous ap­plic­a­tions? And is the al­ter­ing of memor­ies a hu­mane way of help­ing those who suf­fer, or is it some fun­da­ment­al vi­ol­a­tion of what makes hu­mans, well, hu­man?

But on the flip side, if some people are bio­lo­gic­ally pre­dis­posed to PTSD, wouldn’t this be a way of lev­el­ing the play­ing field, of help­ing people un­lucky enough to be­come vic­tims of their bod­ies’ own chem­istry?

“People say, ‘Well, it’s just wrong to in­ter­fere with the nat­ur­al in the realm of memory,’” says Peter Kramer, a psy­chi­atry pro­fess­or at Brown Uni­versity who stud­ies med­ic­al eth­ics, “but the nat­ur­al in the realm of memory does in­volve re­shap­ing and for­get­ting. Maybe the in­jury is more like the un­nat­ur­al.”

As the body of ex­ist­ing re­con­sol­id­a­tion re­search ex­pands””and as sol­diers con­tin­ue to re­turn home burdened by the trauma of their ex­per­i­ences””it’s an is­sue that those who study the brain are likely to grapple with more and more of­ten.

“I was at a con­fer­ence not that long ago where the idea was brought up,” Re­ber says, “and it led to a lot of an­im­ated dis­cus­sion: If you could edit your own memor­ies, are there any memor­ies you’d want to get rid of? If you have a memory of a pain­ful event, do you lose some part of your­self if you get rid of it? Would that be worth the trade?”

“Ob­vi­ously,” he adds, “it’s not a simple ques­tion.”

What We're Following See More »
TAKING A LONG VIEW TO SOUTHERN STATES
In Dropout Speech, Santorum Endorses Rubio
2 days ago
THE DETAILS

As expected after earlier reports on Wednesday, Rick Santorum ended his presidential bid. But less expected: he threw his support to Marco Rubio. After noting he spoke with Rubio the day before for an hour, he said, “Someone who has a real understanding of the threat of ISIS, real understanding of the threat of fundamentalist Islam, and has experience, one of the things I wanted was someone who has experience in this area, and that’s why we decided to support Marco Rubio.” It doesn’t figure to help Rubio much in New Hampshire, but the Santorum nod could pay dividends down the road in southern states.

Source:
‘PITTING PEOPLE AGAINST EACH OTHER’
Rubio, Trump Question Obama’s Mosque Visit
2 days ago
WHY WE CARE

President Obama’s decision to visit a mosque in Baltimore today was never going to be completely uncontroversial. And Donald Trump and Marco Rubio proved it. “Maybe he feels comfortable there,” Trump told interviewer Greta van Susteren on Fox News. “There are a lot of places he can go, and he chose a mosque.” And in New Hampshire, Rubio said of Obama, “Always pitting people against each other. Always. Look at today – he gave a speech at a mosque. Oh, you know, basically implying that America is discriminating against Muslims.”

Source:
THE TIME IS NOW, TED
Cruz Must Max Out on Evangelical Support through Early March
2 days ago
WHY WE CARE

For Ted Cruz, a strong showing in New Hampshire would be nice, but not necessary. That’s because evangelical voters only make up 21% of the Granite State’s population. “But from the February 20 South Carolina primary through March 15, there are nine states (South Carolina, Alabama, Arkansas, Georgia, Oklahoma, Tennessee, Kentucky, Mississippi, and North Carolina) with an estimated white-Evangelical percentage of the GOP electorate over 60 percent, and another four (Texas, Kansas, Louisiana, and Missouri) that come in over 50 percent.” But after that, he better be in the catbird’s seat, because only four smaller states remain with evangelical voter majorities.

Source:
CHRISTIE, BUSH TRYING TO TAKE HIM DOWN
Rubio Now Winning the ‘Endorsement Primary’
2 days ago
WHY WE CARE

Since his strong third-place finish in Iowa, Marco Rubio has won endorsement by two sitting senators and two congressmen, putting him in the lead for the first time of FiveThirtyEight‘s Endorsement Tracker. “Some politicians had put early support behind Jeb Bush — he had led [their] list since August — but since January the only new endorsement he has received was from former presidential candidate Sen. Lindsey Graham.” Meanwhile, the New York Times reports that fueled by resentment, “members of the Bush and Christie campaigns have communicated about their mutual desire to halt … Rubio’s rise in the polls.”

Source:
7 REPUBLICANS ON STAGE
Carly Fiorina Will Not Be Allowed to Debate on Saturday
1 days ago
THE LATEST

ABC News has announced the criteria for Saturday’s Republican debate, and that means Carly Fiorina won’t be a part of it. The network is demanding candidates have “a top-three finish in Iowa, a top-six standing in an average of recent New Hampshire polls or a top-six placement in national polls in order for candidates to qualify.” And there will be no “happy hour” undercard debate this time. “So that means no Fiorina vs. Jim Gilmore showdown earlier in the evening for the most ardent of campaign 2016 junkies.

Source:
×