The American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition contains definitions and diagnostic criteria for every mental disorder you can imagine—including Nightmare Disorder, Rumination Disorder, and Selective Mutism. With a fifth revision of this key text currently in the works, mental health workers around the globe are wondering: should "Internet addiction" be added to the list?

In 2008, the Journal of American Psychiatry argued that "Internet addiction appears to be a common disorder that merits inclusion in DSM-V."

The call to make Internet addiction a diagnosis has been controversial, in large part because the condition so often appears alongside other mental health problems (it may be more of a symptom than a disease). The DSM-V revision committee has since decided that Internet addiction won't get its own listing due to a lack of research, but will be "included in the manual’s appendix instead, with a goal of encouraging additional study."

Currently, those studying bad behavior on the Internet break it down into "at least three subtypes: excessive gaming, sexual preoccupations, and e-mail/text messaging." But surely there are more?

While the DSM-V committee continues to work on its draft of the new manual, we would like to suggest that a few other Internet-related conditions, compulsions, addictions, and maladjustment receive some "additional study" of their own. The following pathologies run rampant on the 'Net:

Generalized Trolling Compulsion. The Internet isn't a "series of tubes." It's more like the world's most incredible bridge, one that connects everyone to everyone else. Beneath this bridge live those with Generalized Trolling Compulsion, brought to you by the same base urges that produced bullfighting, the Roman Coliseum, and roller derby. Note: rehabilitation is possible—but only for Mac users. (See what we did there?)

Comments Derangement Syndrome. When presented with an empty comment form, a controversial topic, and someone who disagrees with one's position, sufferers of Comments Derangement Syndrome take all social and conversational norms they have ever learned, beat these norms with a club, and stuff them into a black trash bag. Upon stepping away from the computer, most sufferers gently remove the norms from the trash bag, fluff them back into shape, and again become a more-or-less normal human being.

Severe Bike Shed Disorder. A sometimes pathological need, when presented with a "piece of code/bit of writing/personal problem" on the Internet, to find something objectionable yet trivial about the "coding habits/writing style/personality and grooming" of the person asking for assistance.

Manic Confirmation Bias. Confirmation bias—only seeing evidence for things you already believe—is endemic to humanity, but its manic variant is seen most often on the 'Net, where terrific quantities of raw news and information make it simple to find support for any of one's preexisting theories, no matter how crazed or one-sided. Often associated with Fanboy Disorder (see below).

Fanboy Disorder. Definitely the prince of Internet psych maladies, Fanboy Disorder has been scientifically shown to be 47 percent more awesome than Generalized Trolling Compulsion. It has no downside—unless you consider being "too awesome" a downside (and you don't, do you?). Seriously, Generalized Trolling Disorder can just go [expletive] itself. I mean, we all know that only losers are trolls. Also, I saw this thing on the Internet once about how those with Fanboy Disorder scored like 20 points higher on IQ tests.

Shill Detection Syndrome. The mistaken belief that someone, despite excruciatingly limited knowledge of the subject in question, can immediately spot "shills," usually of the corporate variety. Most often applied by one Internet commenter to another commenter who has the temerity to disagree. In some cases, what appears symptomatic of Shill Detection Syndrome is, in reality, just a case of Generalized Trolling Compulsion.

Acute Screen/life Confusion. Often baffling to those of an older generation, acute screen/life confusion results in Internet acronyms, abbreviations, and memes being shouted out to other humans in non-computerized settings. Typical examples: blurting out "Ell Oh Ell" in response to a joke, yelling "PWNED!" after beating someone in foosball, or saying to your oddball aunt, "Your ideas are intriguing to me and I wish to subscribe to your newsletter." (Simpler diagnostic criteria: if it ever appeared on 4chan and you have the desire to say it out loud in any setting, you probably have ASLC.)

Delusional Capital Exchange Disorder. DCED is most often witnessed in disgruntled individuals who, in their attempts to communicate disappointment or dissatisfaction, display an asymmetrical level of emotional response that appears to belie a mistaken belief that they have paid a great sum of money for something which they have in fact received for free, and of their own volition (e.g., website news).

Minority Platform Persecution Complex. Primary symptom is an irrational belief that the general public's lack of interest in lesser-known operating systems or software platforms is driven by a vast and intentional conspiracy to marginalize and attack users of said software. It is often coupled with a sense of entitlement and the belief that minority platforms deserve disproportionately higher attention than they obtain. While symptoms are commonly exhibited by Linux users, they are often chronic and debilitating in BSD fanatics and OpenSolaris diehards.

Narcissistic Market Prognostication Imbalance. The delusional belief that, because one doesn't like something, no one else will. As one Ars commenter summed it up in perfect tongue-in-cheek fashion, "So far Geeks have predicted that iPods, iMacs, iPads and the iPhone will be a flop. It's got to the point now that if there isn't Geek Rage on the Internet, I won't buy the Apple product."

Cthulhu Cuteness Mismatch. One of the odder psychological maladies, CCM can occur without warning in any subject exposed to large quantities of Internet-delivered, Cthulhu-themed humor/merchandise. In its early stages, CCM sufferers may browse Etsy and face the temptation to buy "cute" Cthulhonic hot pads for their kitchen. Moderate cases will improperly believe the fiendish primeval terror to be at his cuddliest when turned into an adorably soft plush toy. Truly advanced disease can result in the purchase of insidiously warm Cthulhu slippers, complete with horrific (but fuzzy) tentacles.

LOLpets Disorder. A compulsive need to share pictures of your tabby or pug on social networks. Adding captions may be a symptom of progressive illness, especially if the words descend into LOLspeak. Ars contributor Matt Lasar suffers (badly) from the disease, though he has recently stumbled on a 12-step recovery program which has as its first principle, "Addiction, i haz it."