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People with bipolar disorder alternate between crushing depression and manic episodes. It's treatable, but it's best to prevent these major mood swings. But it's difficult to tell when one is imminent. As part of a series, Joe's Big Idea, NPR science correspondent Joe Palca has the story of a Michigan psychiatrist who's invented a smartphone app that he hopes will work as an early warning system.
JOE PALCA, BYLINE: There are drugs that can prevent the manias and depressions that come with bipolar disorder, and allow patients to live relatively normal lives. But Melvin McInnis says the danger point of one of these episodes recurring is always present. McInnis is a psychiatrist at the University of Michigan Medical Center. He says doctors would like to know when one of these episodes might be on the horizon.
MELVIN MCINNIS: You want to be able to detect that well in advance. And the importance of detecting that well in advance is that, they reach a point where their insight is compromised so they don't feel themselves that anything is wrong.
PALCA: Early detection gives doctors a chance to adjust a patient's medications and stave off full-blown manic episodes.
MCINNIS: It occurred to me a number of years ago that monitoring speech patterns would be a really powerful way to devise some kind of an approach to have the ability to predict when an episode is imminent.
PALCA: McInnis says researchers have known for some time that people with bipolar disorders speak differently.
MCINNIS: Someone who is depressed speaks very slow, and the individual has a number of pauses. And you are sitting on the edge of your seat, often wanting to drag the words out of their mouth. Whereas in manic speech it's going so fast that you can almost hear. And then the other person is jumping from one topic to the next and all over the place and here and there. And then its, oh, and then you see a bird, then they saw the bird, then they saw the bird flirts, and, you know, the turtles, and, you know. And then they're going on and on and on about all these different things, and you just became exhausted listening to them. And you find that you cannot get a word in edge-wise.
PALCA: McInnis wondered if he could pick up hints of these altered speech patterns in people being treated for bipolar disorder when they weren't having a full-blown episode, but might be on the verge of one. So he and some computer science colleagues invented a smartphone app. The idea is that doctors would give patients the app, and the app would record whenever they made a phone call. Once a day, the phone would send the recorded speech to a computer in the doctor's office, and the computer would analyze it for such qualities as speed, energy and inflection. Right now, the app is being tested with volunteers.
MCINNIS: So we have, at the present time, around 12 or 15 phones deployed and individuals that are participating in a longitudinal study of bipolar disorder.
PALCA: So far, the results are encouraging. McInnis says the software is reasonably good at detecting signs of an impending manic attack. It's not quite as good at catching an oncoming depression. For now, this app is only intended for patients with bipolar disorder. But McInnis thinks routinely listening for changes in speech could be an important tool for early detection, not just of mental disorders but of other conditions, maybe even lung or heart disease. Joe Palca, NPR News.