It's generally accepted that crazy is a universal phenomenon. No matter where you live in the world, you're still just a human with a human brain, and it makes sense that all brains malfunction in the same way. Sure, one guy hallucinates aliens while another sees demons, but it comes down to the same illness. But what's awesome (and terrifying) about the brain is all of the ways it defies explanation. For instance, there is a long list of absolutely bizarre mental disorders that are extremely common in one place, and only one. Some of the weird-ass mental disorders that have popped up over time include ... #6. Zero Stroke After World War I, Germany experienced a period of ridiculous inflation so rapid that, reportedly, the value of a cup of coffee could double during the time it took to drink it. This also meant that everyday goods could suddenly be priced at millions or billions of marks (with salaries changing just as fast), turning price tags into utter nonsense. As a result of the sudden confusion and anxiety that accompanied every purchase ("Is 50,000 marks a lot for a can of beans?" "Well, you can get a cup of coffee for 35,000 marks -- oh, wait, they changed it again ..."), Germany saw the rise of a brand new and unique mental disorder specific to that place and time: zero stroke. Because the value of the German currency was plummeting at such an absurd rate, everyone had to attempt to learn advanced mathematics just to calculate the cost of a loaf of bread (which at the height of the troubles could have cost thousands of billions of marks). The effect was that people actually began to grow so dizzy from all the zeros they had to write down every day that it drove them slightly crazy. Imagine being unable to sleep at night because your brain is compulsively counting dozens of zeros and you can't stop. Cashiers, bookkeepers, and bankers were most prone to this affliction. Besides a compulsion to write endless strings of zeros, individuals who suffered from this condition would reportedly become confused when referring to numbers and would state that they were 10 billion years old or had 40 trillion children. That's right; some people will be driven clinically insane if forced to do too much math. #5. Semen Loss Syndrome You wouldn't think it due to its struggles with overpopulation, but China has somewhat of a sexual repression problem. Cultural anxieties about sex were compounded when the communists took over with even more prudish rules about how men and women could interact with each other, and by the 1980s and '90s, thousands of people were flooding Chinese hospitals complaining of a condition called shenkui -- being so sexually frustrated that they could barely function. Traditionally, the Chinese believe that sexual intercourse is risky, because losing semen leads to a decrease in yang, a kind of life essence. Lose too much of it, and you might as well have lost a pint of blood. If you were ever concerned about how much you masturbated as a teenager, spare a thought for the Chinese, who may live in fear that the next wet dream could kill them. Anxiety over how much they're whacking it leads to shenkui, or semen-loss syndrome, which manifests as dizziness, back pain, fatigue, weakness, insomnia, frequent dreams, and sexual dysfunction. Of course, you might think that this is just a silly superstition and it's all in their heads. But before you click away to the porn site that we know you have open in another tab right now, consider India. The Indians have another culturally specific syndrome that they call dhat, which is also brought on by anxiety about how much seed they're wasting into a box of tissues. The symptoms? You guessed it -- weakness, fatigue, insomnia, and sexual dysfunction. So ... we guess what we're saying is that if you masturbate so often and so vigorously that it actually causes physical fatigue, dizziness, and back pain, please see somebody. Even if your country doesn't have a name for the disorder, it doesn't change the fact that your genitals are mere flesh and blood and have their limits. Hell, if you smack around any part of your body hard enough and long enough, you'll eventually pay the price. #4. Arctic Hysteria It's pretty easy to guess where you'd have to be living to fall victim to Arctic hysteria. Known to the Eskimo people as pibloktoq, incidences of this particular madness occur predominantly during winter in the coldest places on Earth, and can sometimes reach epidemic proportions. Attacks of Arctic hysteria may last for only a few minutes, but in that time, sufferers are known to start screaming incomprehensibly, strip naked and run around on the ice, and attempt superhuman feats like walking on the ceiling. And sometimes, for some reason, they eat their own poop. They'll often wake up later with no memory of the whole thing, presumably wondering why their breath smells so bad. It's such a common occurrence among Eskimos for members of their tribe to start acting like they're possessed by poop-loving devils that they just leave the victims to their own devices until they snap out of it. Although the women of the tribe have been found to be most at risk, cases of Arctic hysteria have also been recorded among stranded European explorers. There are even reports of dogs coming down with it, although we don't know how they could tell, since being naked and eating poop is not exactly unusual for dogs. Natives tend to believe that the condition is a result of witchcraft, but some researchers have suggested that Arctic hysteria may be linked to an overdose of vitamin A. The Eskimo diet contains a large amount of vitamin A, and apparently the symptoms of overdoing it can be pretty similar to a case of pibloktoq. The poop eating is just a bonus. #3. Wild Pig Syndrome If you're a young male living in tribal New Guinea, newly married, and facing financial pressure, then you're at risk of falling victim to wild pig syndrome. That means you're likely to embark on a five-finger-discount shopping spree for useless crap and not remember it in the morning. The syndrome, which exclusively afflicts male members of the community between the ages of 25 and 35, is so named for its victims' tendency to become aggressive and hyperactive like feral animals. It's also characterized by the compulsion to steal random, usually meaningless objects, so maybe it's better described as "asshole monkey syndrome." In most cases, the victims venture into the woods for several days, during which time they destroy the stolen objects, and then return to their village without remembering the episode, only to be reminded of the event by other villagers whose shit has recently gone missing. Traditionally, natives of New Guinea believe that the condition is caused by being bitten by the ghost of a recently deceased tribe member and can be cured by holding the sufferer over smoke until he returns to normal. Which makes us think that zombie movies in New Guinea probably suck. #2. Brain Fag Syndrome Imagine you're a student in a sub-Saharan country trying to study for your exams when suddenly your brain just loses the ability to grasp what you're reading. You're exhausted, you can't speak properly anymore, and your hand shakes so much that you can't write. You're experiencing what's known in Africa as brain fag syndrome. Although the name sounds like it was coined by surveying middle school boys, apparently it's short for "fatigue," and it only seems to affect students in West Africa -- more specifically, those studying in Western educational systems. Researchers studying the condition have noticed that the more proficient in the English language a person is, the higher his or her risk of coming down with the condition. And it's not just a regular case of the exam willies -- more extreme cases include pain, feelings of pressure in the head or neck, tightness, blurring of vision, rapid heartbeat, and even crawling sensations under the skin. So why only African kids in Western schools? Scientists think it may have something to do with the way the brain deals with this specific clash of cultures. Or rather, doesn't deal with it. Whatever the cause, 4 out of 10 school students in West Africa are at risk of getting brain fag, which is not a diagnosis that any teenager wants to hear from a doctor. #1. Crazy Sickness For most of us, a seasonal outbreak means that you're likely to spend a few days stuck in bed with your head full of mucus. If you're a young girl of the Miskito people of Central America, unfortunately, you're more likely to go into convulsions and start vomiting insects. This is what the Miskito people call grisi siknis, or "crazy sickness." Grisi siknis is a highly contagious and bizarre condition that causes manic convulsions and even coma in its victims. During spells, sufferers attempt to flee their community with their eyes closed, seizing any weapon they can find with which they appear to try to defend themselves against invisible attackers. According to eyewitnesses, sufferers mysteriously gain extraordinary strength, and often upward of four men are required to restrain them and tie them down with ropes. There are reported cases of 15-year-old girls with grisi siknis overpowering seven men. Basically, they all turn into that girl from The Exorcist, minus the pea soup vomit. The most baffling and terrifying thing for scientists studying the condition is that they really don't know what the hell is going on. It seems to spread like a virus, but blood samples from sufferers have turned up nothing. Drugs and injections just seem to make it mad. Outbreaks have been reported as far back as 1800, and an epidemic that began in 1910 is said to have lasted for a period of 20 years. There were 65 cases last year. Hell, maybe this is one occasion where the demon possession explanation is the right one.