Perhaps one of the strangest and most controversial medical mysteries out there today, Morgellons syndrome involves the sprouting of inorganic material -- including fibers and crystals -- from the skin.
No solid evidence yet exists for the condition, and many doctors today say it is likely more a psychological condition than a physical one. That is, of course, assuming that the individuals who say they suffer from it do not actually have these objects growing from their skin.
In 2006, Brandi Koch of Clearwater Beach, Fla., told ABC News that she was one of many to suffer from the condition; she claims she has colored fibers coming out of her skin.
"The fibers look like hair, and they're different colors," Koch said.
And while most medical professionals doubt the existence of the condition, at least one -- pediatrician Dr. Greg Smith of Gainesville, Ga. -- claims to actually have experienced the condition firsthand.
"It felt like somebody stuck a pin in my toe and wiggled it and it just continued to hurt," Smith told ABC News in 2006. "I've certainly had those crawling sensations, and the fibers which come out of the skin are really bizarre, and really odd."
However, Dr. Vincent DeLeo, chief of dermatology at New York's St. Luke's-Roosevelt Medical Center, weighed in on what he'd say to someone who came to him with this condition: "I don't think this is any different than many patients I've seen who have excoriations and believe that there is something in their skin causing this."
DeLeo says the open lesions are a result of scratching the skin.
Maybe you never got along with your little brother or sister. Perhaps numbers make your stomach turn, or maybe you drink a bit too much coffee for your own good.
If you're like most people, none of these situations poses a real threat to your daily routine. But take any of these situations and imagine them magnified exponentially. Suddenly, you're dealing with Sibling Rivalry Disorder, Mathematics Disorder or one of any number of Caffeine-Related Disorders.
Like some of the other diagnoses on this list, these conditions appear in one form or another in the DSM. And Kupfer says there is a good reason for including them; specifically, he says these collections of symptoms can often cause a certain level of personal distress or impairment -- the very definition of a disorder.
"In a way, what we are looking for is to diagnose things reliably to allow individuals to seek treatment," Kupfer says.
With regard to Sibling Rivalry Disorder, treatment can mean counseling that could solve family problems or prevent future psychological conditions. Teaching someone to cope with caffeine abuse may save them from sleep-related problems. It is in these situations, Kupfer says, that labeling such conditions as disorders is helpful.
But Hadler cautions that labeling can also have its downsides.
"A label will always change your self perception," he says. "Sometimes it elicits a positive change, sometimes a negative one."
And as far as Mathematics Disorder goes, most are skeptical that receiving such a diagnosis will get you much pity from your teachers.