RACHEL MARTIN, HOST:
We are about to go deep - deep into your brain.
STEVE INSKEEP, HOST:
With a story about deep brain stimulation, or DBS, which sounds like a kind of massage, actually. But it means that patients get an implant that delivers small pulses of electricity to their brains.
MARTIN: It's often used to treat Parkinson's disease. But for years, researchers have been trying to figure out how to use it to treat psychiatric disorders.
INSKEEP: Results and experiments so far have been mixed. Many patients see no benefit. But some with obsessive-compulsive disorder have seen big changes.
MARTIN: Like the next woman you're going to meet. For privacy, we are withholding her last name.
Alix Spiegel from NPR's INVISIBILIA has her story.
ALIX SPIEGEL, BYLINE: During the appointment, Megan didn't have to do that much, just sit in a chair while one of the doctors from the experiment used what looked like an oversized remote control to reprogram her electricity levels. Even after five years of having the implant, getting her electricity adjusted was unpredictable. Sometimes it went fine. But having electrodes in your brain is really complicated. And occasionally, the adjustments didn't go well.
UNIDENTIFIED DOCTOR: While you were talking, I slowly ramped it up again. Anything different now?
MEGAN: Slightly more aware.
UNIDENTIFIED DOCTOR: OK.
MEGAN: It's not like in the past, where it was like, oh, I feel good. But it's, like, a different feeling.
SPIEGEL: After the doctor turned her up higher, Megan said she felt better. But then he decided to dial it back just a notch. He was worried that too much electricity might make her manic.
UNIDENTIFIED DOCTOR: Now, if you notice me turning it down, then maybe I'll change my mind on that.
MEGAN: (Crying) I'm sorry; don't do it.
UNIDENTIFIED DOCTOR: Did you just feel it?
MEGAN: (Crying) I don't feel very good at all right now.
UNIDENTIFIED DOCTOR: Oh, so something just changed? That's why - because in the process of reconfiguring it, it just temporarily went off. So you really noticed that. Give me one second.
SPIEGEL: Deep brain stimulation - for Megan, getting the device in her brain to work right was a struggle. But on the other hand, so was having obsessive-compulsive disorder. She'd tried all kinds of treatments to feel better, but nothing worked. And so after she dropped out of college, she spent several years basically in her bedroom obsessing not only about things like folding her clothes, but also all the things that might happen if she ever left her house.
MEGAN: If I went for a drive, I could hit somebody, whereas, if I stay in my room, I still have to do some compulsions. But at least I'm not going to hurt anybody. So...
SPIEGEL: Megan felt like she'd run out of options, which is why, after hearing about the DBS experiment, she signed up and why, in 2013, she found herself sitting nervously at Massachusetts General Hospital while a nurse ran clippers over her scalp and her hair fell like dead leaves around her.
MEGAN: I remember kind of wanting to cry a little bit.
(SOUNDBITE OF MUSIC)
SPIEGEL: Megan had to be awake during the operation so they could test whether they'd found the exact right spot in her brain. But she was pumped full of so many drugs, the doctors around her felt far away.
MEGAN: Most of the time they sounded like "Peanuts" adult - the teacher.
(SOUNDBITE OF MUFFLED CROSSTALK)
SPIEGEL: A few months later, the doctors began the difficult process of finding the right dose of electricity for her. The first day they turned her on, they started really low. But once the doctor got to 3 volts, Megan began to really respond.
(SOUNDBITE OF MUSIC)
MEGAN: It was a feeling of euphoria, like - not just an emotional sensation of, I feel so unburdened, but just a physical sensation, like, after a really great massage and maybe a shot of bourbon. You know, like...
SPIEGEL: So 3 volts is where the doctors left her - 3 out of a possible 10.5. The doctors needed to know how the setting would affect her over time. So they asked her to stay at a hotel near the hospital and check in after a couple of days.
Megan remembers walking out of the hospital feeling like a completely new person.
MEGAN: I found myself feeling more comfortable talking to strangers. Like, if I went to the store, you know, checking out with the cashier - you know, like, making little conversations wasn't hard for me anymore, which was an amazing thing because normally I was so caught up in my own obsessions, I just didn't have the ability to do that. But I just felt so much freer. It was like someone spring-cleaned out my brain and took out all the unnecessary thoughts.
(SOUNDBITE OF MUSIC)
SPIEGEL: And the first day was great. But then the next day she didn't sleep. And the following morning, her mind started racing. And for some reason, she felt the need to physically push at the world around her.
MEGAN: Pushing my hands and legs against the floor and the wall, like, this need to get some tension out.
SPIEGEL: When she got to the hospital the next day, her doctors told her that she'd had a submanic episode. So they had to turn her off - like, completely and totally off.
MEGAN: So I actually left with nothing. And I remember feeling very deflated. And I thought this was just a fluke; I'm never going to feel that good again.
SPIEGEL: The good news is that Megan was wrong. It took about five years of struggle - of wires getting broken and batteries not working. But in the summer of 2018, her DBS implant finally began to function consistently. Today, Megan has a job, a husband, a home with a dog and a treatment that works every day.
MEGAN: I like to say I'm cured just because of where I was. It was awful. Like, and even though I still have OCD, it's nothing to complain about.
SPIEGEL: But then there's the less good news, which is that this happiness that Megan has built for herself, it might not last. This has to do with her levels. The highest amount of electricity that you can feed from the device to the brain before it begins to damage tissue is 10.5 volts. And she's now at about 6. And since she's only in her 30s, that's something she worries about.
Every six months or so, she acclimates to whatever new setting she's been given. And the benefits begin to wear off, which is why Megan tries to make each setting last as long as she possibly can.
MEGAN: Because it only goes so high. And you don't want to acclimate to a level when you don't have to.
(SOUNDBITE OF MUSIC)
SPIEGEL: Since the technology is still experimental, there's no way to know how this will work out. What is certain is that Megan's doctors want to keep on improving it. And several scientists told us they believe DBS will one day be used not just to treat people like Megan, but to enhance people who have no disorders. So the device in Megan's head, it might one day have implications for us all.
Alix Spiegel, NPR. Transcript provided by NPR, Copyright NPR.