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The Electric Mood-Control Acid Test

A startup called Thync will sell electrodes that you put on your head to improve your mood. The results may vary to a surprising degree.
March 12, 2015

I’m working on a story that’s almost due. It’s going well. I’m almost finished. But then everything falls apart. I get an angry e-mail from a researcher who’s upset about another article. My stomach knots up. My heart pounds. I reply with a defensive e-mail and afterward can’t stop mentally rehashing my response. Taking deep breaths and a short walk don’t help. I can’t focus on finishing my story, and as the deadline approaches, that makes me more uptight and it gets even harder to write.

But then I apply electrodes to my head and neck, power up a small electronic device, and shock myself. Within a few minutes I calm down. I can focus on my story. I meet the deadline.

The device, which you’ll be able to buy later this year for a price that has yet to be disclosed, was developed by a team of neuroscientists and engineers at the startup Thync. It’s a small, curved piece of plastic that snaps onto electrodes and produces pulses of electricity. A wireless signal from a smartphone app controls the frequency and intensity of the pulses, gradually changing them in five- to 20-minute long programs that Thync calls vibes. The amount of electricity it produces is small—once it’s set up properly, I can barely feel it. Yet Thync says it has a marked impact on key parts of a person’s brain. An energy vibe, the company contends, can make you feel as if you’ve just had a Red Bull or similar energy drink. The calm vibe—the one I just ran—is for “whenever you’re frustrated, anxious, or stressed.”

The device doesn’t work for everybody, and it’s far too soon to make the call on whether Thync’s hypothesis about how it works is true.

There’s no question that I feel a significant change from the calm vibe, but could that be a placebo effect? I wonder if it works on everyone, and if it works the way Thync says it does.

To find out, I ask three researchers with expertise in neuroscience to review the results of a study Thync posted last month in the open-access online journal BioRxiv, where papers are not peer-reviewed before publication. The paper details experiments that measured the effects of Thync’s calm vibe. I also test that vibe on eight people in the office, and I use the device myself multiple times a day for several days to compare the effects in different settings.

What I find is that the company’s claims are plausible, but the device doesn’t work for everybody, and it’s far too soon to make the call on whether Thync’s hypothesis about how it works is true.

The idea of using electricity to affect the brain is hardly new. Researchers of varying character have been shocking people’s heads for hundreds of years. One scientist jokes that the high point of the hype cycle for electrical treatments was 1818, when Frankenstein was published. While technologies like electroshock therapy have inflicted severe damage on patients, doctors are favoring newer electricity-based therapies. These include a safer version of electroshock therapy called electroconvulsive therapy, deep brain stimulation, and transcranial magnetic stimulation (which induces electric current in parts of the brain using an external magnetic coil). They’re used to treat a variety of disorders, including Parkinson’s and depression.

But these technologies are expensive and need to be administered by trained personnel. Thync’s technology is tantalizing in part because it promises to have significant effects using very low electrical currents safe enough for untrained people to use at home. The device Thync will sell later this year won’t be marketed as a medical device, but the company hopes it can eventually be used to help people with anxiety disorders and other medical problems.

Thync says its device is an improvement over a similar-sounding technology called transcranial direct current stimulation, or tDCS. In 2000, Walter Paulus, a German researcher (and the one with the Frankenstein joke), published a paper showing that applying weak electrical currents to certain parts of a person’s head could have an effect on the brain that changed the signals it sent to muscles. In the last few years interest in the technology has exploded, with researchers suggesting that tDCS can improve higher-order brain functions such as memory and learning. These results and the fact that, in its crudest version, tDCS requires little more than a pair of wet sponges, wires, and a nine-volt battery, have spawned a do-it-yourself movement. (Be careful if you try this: you can hurt yourself with homemade devices if you don’t know what you’re doing.) Some video gamers swear by the technology as a way to improve their performance—at least one commercial device, the, is marketed to them.

But while there have been some promising tDCS studies, results haven’t been consistent. A review published in January looked at over 1,000 papers to see if any results had been confirmed by more than one research group. None had, aside from Paulus’s early results. The review concluded that there was “no evidence of cognitive effects.”

Jamie Tyler, a neuroscientist and cofounder of Thync, met Paulus in 2009 and quickly became interested in tDCS. “I was very excited,” he says. “I thought it opened up limitless possibilities.” But after diving into the literature and trying unsuccessfully to reproduce the findings, he says, “I became a little jaded. I went through this whole space and concluded the claims out there are really overblown.”

Tyler suspected the devices were working in a different way than people thought. For the most part, researchers believed that tDCS devices were delivering small amounts of electricity through the skull to affect the underlying parts of the brain—hence the “transcranial” in tDCS.

But there are problems with this hypothesis. “Electricity gets diffused by your skull. Then it hits the cerebral spinal fluid—the salt water surrounding your brain—and that again diffuses it and shunts the current to god knows where,” says Alik Widge, a psychiatrist at Massachusetts General Hospital. As a result, he says, in many cases researchers aren’t stimulating the areas of the brain they think they are.

In part based on animal studies, Tyler surmised that rather than affecting the brain directly, tDCS electrodes were primarily stimulating cranial nerves that lie just beneath the skin. These nerves connect directly to areas in the brain involved in a person’s flight-or-fight response, triggering or suppressing the production—depending on the type of stimulation—of stress-related neurotransmitters such as norepinephrine. Tyler says that “every one of the effects that’s shown in the tDCS world can be explained via this mechanism.”

If Tyler is right, it could explain why tDCS results have been so hard to replicate. Researchers position tDCS electrodes based on the assumption that they affect the areas of the brain directly below. But sometimes they may be accidentally stimulating the cranial nerves instead, leading to inconsistent results. Based on his new hypothesis, Tyler changed where he placed the electrodes, targeting these nerves specifically.

Early experiments showed enough of an effect to suggest the hypothesis was right, Tyler says. But the effects weren’t huge. The next step was to amplify the effect by increasing current levels without causing pain or skin damage. Researchers at Thync, which was founded in 2011, did this in part by using pulses of electricity, rather than steady current, and operating at frequencies that don’t stimulate pain receptors.

I experienced the difference that these measures make when I tried out a conventional tDCS device side-by-side with Thync’s technology. At three or four milliamps of electrical current, conventional tDCS was quite painful. That’s why most experiments are done at around one milliamp. In contrast, I couldn’t even feel the pulses from Thync’s device at 10 milliamps.

Thync now uses conventional tDCS devices as a comparative “sham” in its experiments—people can feel it on their skin, but according to Tyler, it has no measureable effects on their mood. In the BioRxiv study, Thync reported that 77 of 82 subjects reported that the Thync device made them more relaxed than the sham did. In a smaller experiment involving 20 subjects, the company found that using its device lowered the body’s response to stress by 50 percent, as measured by the electrical properties of skin. A biological marker of stress found in saliva increased by 6 percent in people using conventional tDCS, but went down by 20 percent in those who got the Thync treatment.

Outside scientists say the study methods were basically sound, although they questioned whether the subjects might have been able to guess which was the sham treatment and might have been influenced by that. And perhaps more importantly, the study was done by the company itself and hasn’t appeared in a peer-reviewed journal.

“This must be like one-15th of what people feel in opium dens. I feel super-mellow.”

That means Thync is really still in the same position as tDCS—its results haven’t been replicated. For now, Thync is keeping the exact properties of its vibes a secret; outside scientists will have to wait to do their own verification until Thync releases its device. “Is it even possible that their technology works? Yes, it is possible,” Widge says. “Their study is not perfect, but it’s reasonable. It’s a first step. It should be used as a springboard to do a whole bunch more investigation.”

My own informal survey suggested that the effects can vary a lot depending on the person. Two of my eight coworkers felt no calming effects at all. Four experienced mild ones; two experienced profound effects similar to what I had. One told me it’s a “letting go kind of sensation, like I could just kind of sit here.” He smiled and added, “This must be like one-15th of what people feel in opium dens. I feel super-mellow.”

The setting seems to matter. The calming vibe is most intense for me when I am slouched into my couch at home with the lights dimmed. When I use the device at work, the effect is much less pronounced.

Thync says the energy vibe—which is purportedly achieved by increasing the brain’s production of norepinephrine instead of suppressing it as with the calm vibe—can make people feel like they’ve consumed 20 ounces of Red Bull, which has caffeine, sugar, and vitamin B. But it seemed to have a small effect on me, much less obvious than the effect of the calm vibe, and Thync hasn’t published detailed data to support its contention.

My conclusion is that it’s too early to tell what fraction of Thync users will feel effects. (The company also says that my tests used beta devices and software that will be improved before the product is launched.) Uncertainty about what it actually does, combined with the inherent complexities of the brain, makes simple answers difficult to come by. Is it worth giving it a try? I asked Joan Camprodon-Gimenez, director of the Laboratory for Neuropsychiatry and Neuromodulation at Massachusetts General Hospital, whether he’d recommend Thync’s calm vibe for patients suffering from anxiety disorders. He says he needs to see more research first. “That said, one of the benefits of this device is that it’s very, very safe,” he says. “That’s always encouraging. The worst-case scenario is it does nothing.”

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