On October 6th, I find myself in the gleaming office of a Boston biotech. I've been seated in a clear plastic chair, where I am about to try an experimental medicine for a brain disorder I don't have.

The space is home to PureTech Ventures, the parent company of Akili Interactive Labs, which makes the new medicine. Since December, children in Florida and North Carolina have also tried the treatment as part of a formal clinical trial for attention-deficit hyperactivity disorder (ADHD). The medicine is unusual because of its delivery system: an iPad or iPhone. That's because the medication is a video game called Project: EVO.

Until now, I haven't touched a video game since about 1991. What if I fumble the mechanics, or worse — what if the game deems me cognitively deficient? One of Akili's founders, 32-year-old Eddie Martucci, hands me an iPad and I see my avatar: a yellow humanoid, floating on a jet-fueled raft down a crooked, icy river. My task seems simple: I tap on blue fish that zoom overhead, but avoid the red and green fish, as well as blue birds. Of course, I'm also steering the raft to avoid frozen spikes along the riverbank.

As I get better, the game instantly gets harder

It's hard. It feels like I'm constantly missing my targets and smashing into the sides. Most frustrating — and addictive — of all: as I get better, the game instantly gets harder.

If Akili's clinical studies are successful, doctors will one day prescribe EVO for ADHD as well as a variety of other disorders affecting so-called executive function — the ability to plan, inhibit actions, and quickly switch between tasks. The game has been part of a dozen clinical trials to date, involving people with ADHD, Alzheimer's, autism, and depression.

The plan is realistic enough that Big Pharma wants in: Akili has already struck deals with two traditional drug companies, Pfizer and Shire. Within the industry, Martucci says, "there's definitely a growing receptivity to digital technology."

Over the past few years, a torrent of studies on video games and brain function have spurred a booming consumer market. The "digital brain health" industry reportedly grew from $600 million in annual revenues in 2009 to more than $1 billion in 2012; the biggest players are names like Lumosity, Cogmed, Posit Science, CogniFit, and Brain Resource.

But most companies aren't making medical claims; they haven't done the trials necessary for that. And what's more, scientists have said that these games promise quick-fixes they can't deliver.

In contrast, Akili is navigating through clinical trials required for EVO to become an FDA-approved medical device. If they make it, they'll have access to a completely untapped market: patients. "We don't see other people playing in that space," says Akili co-founder Eric Elenko. "From a business perspective it represents a more lucrative opportunity."

THEY'LL HAVE ACCESS TO A COMPLETELY UNTAPPED MARKET: PATIENTS

The drugs used to treat brain disorders don't just have side-effects; they usually don't address executive dysfunction. That's because drugs don't have feedback loops that aid learning, according to Adam Gazzaley, a neuroscientist at the University of California, San Francisco. "Drugs are relatively blunt instruments," he says. "They're not selective for networks and circuits in the brain."

Gazzaley got interested in scientific gaming around 2008, while conducting brain-scanning studies aimed at executive function. He wondered whether training people could improve their everyday executive function skills. But his laboratory tasks were boring; getting volunteers to play them for hours was a "preposterous" idea, he recalls.

So Gazzaley got in touch with his friend Matt Omernick, a game designer at LucasArts who was working on Star Wars: The Force Unleashed. The duo, along with other engineers and researchers, had evening get-togethers to talk about how to translate the lab's tasks into something fun. "He'd feed us sushi and beer and we would brainstorm," Omernick says.