The American Psychiatric Association\u2019s latest version of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), which was published in May 2013, includes several disorders and syndromes that were not recognized as real mental illnesses in the past. One of these newly recognized conditions is avoidant\/restrictive food intake disorder \u2014which is more commonly known as selective eating disorder. A condition that first appears in early childhood, selective eating disorder is sometimes referred to simply as \u201cpicky eating,\u201d but the use of this phrase is highly misleading. While it is not uncommon for toddlers to be fussy about food and to refuse to eat certain dishes, selective eating disorder, or SED, is a much more extreme condition that causes those suffering from it to reject all but a very small sampling of the foods they are offered. In fact, SED victims will routinely reject entire food groups such as vegetables or meats, apparently because they are revolted by the texture, smell, or appearance of those items and cannot bear the thought of chewing and swallowing them. The main problem with SED is that unlike picky eating, it is not just a stage that kids will automatically grow out of as they age. If left untreated or unaddressed, selective eating disorder can and frequently will continue into adulthood, leaving its victims with severely restricted diets that are seriously lacking in nutritional range and value. Foods that contain high amounts of fat, sugar and starch tend to become something of a fetish for adult SED sufferers, and in some extreme instances they may literally eat no more than one or two different types of foods on a day-in\/day-out basis. Needless to say man cannot live by pizza, white bread, or Chicken McNuggets alone, at least not if he\u2014or she, SED is an equal-opportunity enemy\u2014expects to remain healthy and resistant to disease and chronic illness. It is true that young adults who suffer from SED generally aren\u2019t obese and usually don\u2019t show any significant signs of ill health, as the body is quite resilient and can adapt to diets lacking in vital nutrients for awhile (also many SED sufferers rely on vitamin and mineral supplements to help partially cover for these deficiencies). But over the long term, diets that are restricted to just a handful of non-diverse foods are bound to cause serious distress and dysfunction in the human organism. Because it has taken medical science so long to recognize the existence of selective eating disorder, research into the condition has up to this point been scant. This is especially true on the question of SED and aging, so at the present time we really have no idea how people suffering from this disorder are likely to be adversely impacted in their later years. And because SED has been studied so infrequently\u2014and often not even acknowledged by medical professionals unaware of its existence\u2014treatment regimens for this condition are still in what would have to be termed a very primitive stage. It is believed that gradual exposure and desensitization techniques can help SED victims, whether child or adult, overcome at least some of their aversions to particular types of foods. But while a few therapists claim to have successfully treated those exhibiting SED symptoms by exposing them to formerly scorned foodstuffs one small piece at a time, controlled studies of this approach have been all but nonexistent. Consequently no one really knows for sure whether those being helped by such methods are actually hard-core SED sufferers, or just individuals with a milder form of this mysterious disorder. Little is known about what actually precipitates the onset of SED, although there does appear to be a genetic link in many cases (it tends to run in families, in other words). But simply establishing the existence of genetic factors does not explain why specific children will come down with this disorder while their siblings will remain unaffected. SED does manifest more frequently in those who also suffer from some type of gastrointestinal or swallowing disorder, however, and it also tends to co-occur with OCD and autism spectrum disorder, which would seem to suggest that the existence of other mental or physical health problems may be responsible for the expression of SED symptoms in those who carry a genetic predisposition for this condition. But at this stage, most of what can be said about selective eating disorder is based on anecdotal testimony collected from adult SED sufferers or the parents of children who have been afflicted, which means that our understanding of this illness is still somewhat speculative and theoretical. Because of the shame and embarrassment they feel, SED sufferers usually go to great lengths to hide their behavior from others. They will try to avoid any social situation that involves eating, even when the only ones present are trusted friends or family, and the thought of dining out at a restaurant or in any other public setting fills them with feelings of horror and dread. This avoidance behavior and the anxiety that accompanies it are a burden SED sufferers must carry in addition to the health risks associated with their poor nutritional practices (it is almost unheard of for SED victims to eat only fruits or vegetables), and being forced to constantly hide the truth about their eating habits from others no doubt puts an enormous amount of destructive psychological strain on people whose health is already being gradually eroded away by the lack of balance in their diets. You Are What You Don\u2019t Eat Even though specific treatment options for SED are somewhat limited, due to the lack of research and the fact that most psychiatrists and psychologists simply aren\u2019t that familiar with this disorder, any parent whose child is showing signs of extreme picky eating should consult with a child psychologist to get feedback and advice. Adults suffering from the symptoms of SED should also seek guidance from a mental health professional, and they should also schedule regular checkups with their doctors to make sure that their physical health is not being damaged by their poor dietary habits. Now that the DSM-5 has officially acknowledged the existence of Selective Eating Disorder, we can only hope that awareness about this condition will increase and more medical research dollars will be invested to study it in-depth. But if victims of SED are willing to come forward and talk about their experiences with medical professionals and therapists right now, this will do much to help bring this unfortunate disorder out of the shadows and into the light of day.