AD Quality Auto 360p 720p 1080p Top articles1/5READ MORE11 theater productions to see in Southern California this week, Dec. 27-Jan. 2Yousef, who wasn’t interested in such clinical distinctions, mashed the accelerator on his Mercedes-Benz sedan, swerved and sped away, a shotgun blast echoing through the air. The incident at a Victorville intersection was far from isolated, according to the study released Monday in the Archives of General Psychiatry. As many as 16 million Americans could suffer from IED, which manifests itself in violent, inappropriate behavior. Screaming, threats of death and destruction – and, when a car enters the mix, road rage. The nationwide study, funded by NIMH and conducted by researchers at Harvard Medical School, examined more than 9,000 subjects. With as many as 7 percent of them experiencing some form of IED, that extrapolates to 16 million people nationwide. The average onset came at 14 years old, predating episodes of depression, anxiety and drug and alcohol abuse. The average IED sufferer will fly into a rage 43 times in their lifetime, racking up more than $1,300 in damage to others’ personal property. “People think it’s bad behavior and that you just need an attitude adjustment, but what they don’t know … is that there’s a biology and cognitive science to this,” Dr. Emil Coccaro, the chairman of psychiatry at the University of Chicago’s medical school and one of the study’s authors, told The Associated Press. The symptoms can be treated with antidepressants or anger-management therapy, Coccaro said, though less than one-third of sufferers have ever received treatment. Leon Levy, an office manager from West Hollywood, sees nothing wrong with the occasional outburst. While driving to work through Los Angeles’ choked streets, he’s been both the victim and the perpetrator of wheeled altercations. Conflict on the asphalt happens so frequently, the 27-year-old Levy had to reflect a bit to select his sharpest road rage moment. He settled on a recent dustup that involved another car driving too slowly on Santa Monica Boulevard. As Levy, in a hurry, tried to maneuver around a car “taking its sweet (expletive) time,” the other driver took umbrage and extended his middle finger. Levy, irritated, cut around him and slammed on his brakes. Soon, they were jockeying around each other, engines racing, tires screeching. Eventually, after the other car nearly dented Levy’s BMW, he hurled a water bottle at the driver and sped away. “It’s all about catching the wrong person at the wrong time. It could have happened this morning, and I wouldn’t have done nothing,” he said. “Usually I just blow them kisses, and that fires them up even more.” [email protected] (818) 713-3738160Want local news?Sign up for the Localist and stay informed Something went wrong. Please try again.subscribeCongratulations! You’re all set! Ray Yousef hit the brakes at the stop sign, apparently a little more quickly than the truck behind him preferred. The Moorpark computer programmer looked in his rearview mirror and saw the furious driver pop out of the vehicle, fuming and toting a shotgun. “They’re trying to get home quickly and they think you’re just not going fast enough, I guess,” the 45-year-old Yousef said. “He thought I shouldn’t have stopped in front of him, so he pulled a gun.” It was a case of road rage – an uncontrollable outburst of anger that top researchers now say can be caused by a disease: “Intermittent explosive disorder,” or IED, according to the National Institute of Mental Health.