ETERNAL SUNSHINE OF THE PAIN-FREE MIND

How neuroscience could make bad memories a thing of the past

Words: Matt bean

Dr. Roger Pitman hunts nightmares. Not the vivid phantasmagoria populated by zombies – he’s after the non-fiction variety, the indelible flashbacks that stick in our heads after reality goes awry: machinery slicing flesh, landmines overturning tanks. I’m in Pitman’s Boston laboratory, watching him track a particularly vivid figment, a stab wound that’s plaguing 43-year-old Al Carney. “We’re about to put him back in the most horrifying moment of his life.” Says the Harvard psychiatrist, while next door, Al sits wired up to a battery of biofeedback equipment.

“It’s 8:30am, Thursday, March 30,” a narrator reads into Carney’s headphones. “Talking to Peter Bowman, you become tense. You tell him he needs to fix several things before you pay him. Peter becomes aggressive, you feel a blow to your neck… you realize you’re bleeding profusely from several knife wounds.”

Carney’s vitals ebb and flow across a monitor as he re-imagines the assault, peaking when he’s “stabbed”, but I don’t need electronics to see it’s struck a nerve: he starts fidgeting and his head twitches violently. Carney is one of dozens of trauma victims involved in Pitman’s study of the experimental drug Propranolol. No one, especially not Carney, knows whether he’s actually taken Propranolol or a placebo, but he’s hoping it’ll stop the spiral of substance abuse and insomnia that the stabbing started.

Pitman’s study leads a new wave of research that could treat the harmful effects of extreme stress, especially post-traumatic stress disorder (PTSD). Current treatment – therapy coupled with drugs like Prozac – fails more often than it succeeds. But Pitman hopes that within five years, Propranolol could make it possible to “defuse” traumatic memories. “Post-traumatic stress disorder is just a memory with its volume set too loud,” Pitman observes. “We’re trying to turn it down again.”

We all have things we’d like to forget. The National Health Service (NHS) estimates that 5% of men will develop full-blown PTSD at some point in their lives. The figure rises to 31% among war veterans, but the disorder also hits closer to home. Domestic disputes, burglaries and even surgery can engrave malignant memories on our brains. Of course, some people can inexplicably shrug-off serious trauma. “We’re all affected by stress hormones,” says PTSD specialist Dr Deane Aikins. “We’re just beginning to understand why some people are more resilient.

Adrenalin, crocodiles and mental scars

“I don’t ever remember looking at my hand,” says 43-year-old Terrel Kyle. Just 25 minutes before the end of a lumber mill shift, Kyle’s left hand met 24 inches of whirring steel. He lost all his fingers. “That moment is just lost. I told my supervisor my fingers were gone, so I knew. But I just walked out and had a cigarette.

Kyle was helicoptered, along with a plastic bag containing his fingers, to Massachusetts General Hospital where a member of Dr Pitman’s team gave him a pill (either Propranolol or a placebo) and he underwent surgery. His hand rejected the fingers, and months later, he can’t erase the memory. “It’s there, all the time, like static, on the fringes of my mind. Anything going around fast – a propeller, car wheels – creates this clenching feeling in my chest.” And Kyle’s symptoms – blackouts, flashbacks, depression – aren’t the only price of PTSD. A 2006 study found the syndrome raises the levels of a blood-clotting agent, increasing the risk of heart disease. It’s also been linked to immune system and muscular disorders.

Post-traumatic stress is a spectacular breakdown of a normally very helpful bodily mechanism. Bundling an emotional component fits with Darwin’s theory of natural selection, says Pitman. “If you’re a Paleolithic man taking a new route to the watering hole and encounter a crocodile, you’d better remember it – or you’re out of the gene pool. Adrenalin helps you escape and strengthens that emotional component to stop you forgetting.”

But extremely traumatic events can release a torrent of stress hormones. That’s where Propranolol comes in. It blunts their impact on your emotional control centre, so you can log traumatic memories as standard bad memories, rather than world-changing, panic-inducing schisms.

Forgetting to regret

Pitman’s research hinges on administering Propranolol within 6 hours of a traumatic event. “Nobody knows when they’re going to be in an accident or assaulted, so administering a pill within 6 hours is difficult,” he says. “But we can control the memory later, by bringing it back to the point of sensitivity. This could help all kinds of problems: drug addiction, OCD, anything where you need to change the wiring in the brain.” But not everyone believes de-traumatizing is a good idea.

“That’s like playing God with the brain,” says Barry Romo, of the Vietnam-veterans anti-war group. “One of the things that keep us from remaking mistakes is having regret.” Romo believes that the way we interpret memories is an essential part of who we are. “People have a right to medication, but I worry what these drugs will be used for in the wrong hands,” he says. “We don’t want to create storm troopers who are able to perform actions remorselessly.”

Pitman says that’s overstating what such drugs can do. “It’s possible that something like that will be found, but I doubt it will be with Propranolol. And can we hold back medication from people simply to prevent others from abusing it? If we practiced that, nobody would be given morphine for their pain.”

Terrel Kyle won’t know for a year whether he received the placebo or the Propranolol. But learning about his disorder has helped him deal with the flashbacks. “Some people go through years of torture,” says Kyle. Should we be able to take those thoughts away? Absolutely. It’s not about playing God, it’s about feeling human again.”