The ultimate fighter at 25 has a body with a good temperament for training. He can take repeated abuse and repair himself. He can fight four times a year -- or five, or seven -- if he wishes. If he suffers a significant dent (broken bones, damaged eyes, muscles torn from their adhesive) he’ll be ambulatory before long.And he gets attention. Lots of attention. From sponsors, from fans who admire his abilities and from women. He can close a nightclub the week of a fight and not suffer the consequences. He makes a decent wage, gets his training subsidized by sponsor money and splurges when bonuses crop up. He’s not a champion, so he can’t afford to buy the Escalade outright, but he can make the lease payments.The ultimate fighter at 35 has recurring injuries. He’s slower to get out of bed, favors aching knees in the gym and makes frequent apologies after fights for his performances -- often mediocre, often the result of a body that won’t do what it’s told to do. The title shot was a squash match. His head is scraping the ceiling.The ultimate fighter at 40 doesn’t know what else to do for a living. He takes fights in regional shows for a flimsy check, but he collects a lot of them, and they add up. So do the concussions. So do the pain medications.At 45, your knees are gone, so you can’t shoot your way out of a fistfight. Your hands are arthritic and you beg the corner to wrap them carefully. You traded your body out for some bonuses and some women and some cheering. And when that hits -- whenever that hits -- you’re going to burst.On Oct. 6, Junie Allen Browning -- a mid-tier fighter who realized he could turn his media-savvy obnoxiousness into a handful of paydays -- reportedly took 16 pills of anti-anxiety medication Klonopin in a bid to either kill himself or get the wrong kind of attention. He was taken to a hospital where he threatened staff. That same week, he was released by the UFC. His last fight, six months ago, was a loss to Cole Miller Earlier in the year, Josh Neer was arrested for drunken driving and eluding police. Last summer, Quinton Jackson endangered himself and others by driving erratically. Jon Koppenhaver assaulted a man outside a nightclub in 2007, choking him unconscious. Mirko “Cro Cop” Filipovic declared he wished to hang himself after his most recent loss. Mike Guymon’s wife took a gun from him; his intention had been to kill himself. Justin Levens succeeded, taking his wife’s life before his own. Jeremy Williams shot himself in his car. Evan Tanner walked into the desert and was never seen alive again.Like a lot of sports that marry serious physical trauma with modest wages, mixed martial arts is finding itself with a mortality rate, but not in the way its critics expected.J.R. Minkel, a Scientific American contributor, recently wrote an article for Real Fighter exploring the brain matter of combat athletes -- not the abuse suffered, but the neural pathways created or damaged by both their choice of profession and daily intake of it. He quoted a sports psychologist from the University of Florida as having taken an informal poll of prizefighters and grapplers. Out of the 400 who responded to his petition to take an online questionnaire, nearly a quarter exhibited symptoms of depression.Is this surprising to anyone? Think about the odds of performing to parity on the 15 or 25 minutes when it counts the most. Does anyone’s income ever normally come down to less than a half-hour two or three times a year? Even jobs that require some kind of stellar public presentation or faultless performance often forgive a misstep. But in fighting, you need to trip only once.The emotional pressure is overwhelming; physical punishment piles it on. Concussions have been inexorably linked to depression -- as many as 40 percent of head injuries could result in neurological disruption leading to behavioral changes or mood suffocation, according to a study at Montreal Neurological Institute of McGill University. Count concussions suffered in training and you’re smart to buy stock in Pfizer.There are real troubles on the horizon for the majority of athletes in this sport who lose as often as they win, who hobble their way through their 30s and who never experience the lucrative financial or emotional rewards of being a champion. They’re already hurting themselves, and others -- and the sport has barely gotten started. Boxing, home to a longer legacy of punishing the people that love it, can point you to 60 suicides committed by its participants in the past decades.Jackson’s behavior last summer was unnerving -- wild and full of half-baked excuses involving energy drinks and fasting and wide-eyed religious talk. For a man who is so often the energetic focal point of a room, all it took was one loss to cut his cord to sanity.So what are we going to do about it? Like any affliction, preventative measures go ignored. More attention must be paid to a fighter’s brain health -- not only in logging baseline MRIs to compare against scans later, but enlisting a mental health professional to evaluate athletes throughout their careers. Businesses often employ crisis counseling psychologists to help employees cope with traumatic events. In mixed martial arts, every fight is a traumatic event.No one seems overly concerned with repeated concussions, a charming trait shared by the NFL and the growing number of athletes who are living post-career lives in misery as a result. Athletes who have suffered head injury on multiple occasions don’t need to have their tantrums to compete indulged: They need to talk to someone about how to adapt to a life without an audience.My pride in observing this sport comes from its near-spotless safety record. It’s often a viscerally disgusting event -- hematomas, blood, screaming -- but it’s not taking lives, a fact I’ve been happy to spew whenever debate crops up. Now I realize that’s wrong: it’s happening, but in a way so subversive that it’s going unnoticed.The ultimate fighter at 50 isn’t depressing. It’s optimism.