A somatic symptom disorder, formerly known as a somatoform disorder, is any mental disorder that manifests as physical symptoms that suggest illness or injury, but cannot be explained fully by a general medical condition or by the direct effect of a substance, and are not attributable to another mental disorder (e.g., panic disorder). Somatic symptom disorders, as a group, are included in a number of diagnostic schemes of mental illness, including the Diagnostic and Statistical Manual of Mental Disorders. (Before DSM-5 this disorder was split into somatization disorder and undifferentiated somatoform disorder.) A somatic symptom disorder, formerly known as a somatoform disorder, is any mental disorder that manifests as physical symptoms that suggest illness or injury, but cannot be explained fully by a general medical condition or by the direct effect of a substance, and are not attributable to another mental disorder (e.g., panic disorder). Somatic symptom disorders, as a group, are included in a number of diagnostic schemes of mental illness, including the Diagnostic and Statistical Manual of Mental Disorders. (Before DSM-5 this disorder was split into somatization disorder and undifferentiated somatoform disorder.) In people who have been diagnosed with a somatic symptom disorder, medical test results are either normal or do not explain the person's symptoms, and history and physical examination do not indicate the presence of a known medical condition that could cause them, though the DSM-5 cautions that this alone is not sufficient for diagnosis. The patient must also be excessively worried about their symptoms, and this worry must be judged to be out of proportion to the severity of the physical complaints themselves. A diagnosis of somatic symptom disorder requires that the subject have recurring somatic complaints for at least six months. Symptoms are sometimes similar to those of other illnesses and may last for years. Usually, the symptoms begin appearing during adolescence, and patients are diagnosed before the age of 30 years. Symptoms may occur across cultures and gender. Other common symptoms include anxiety and depression. However, since anxiety and depression are also very common in persons with confirmed medical illnesses, it remains possible that such symptoms are a consequence of the physical impairment, rather than a cause. Somatic symptom disorders are not the result of conscious malingering (fabricating or exaggerating symptoms for secondary motives) or factitious disorders (deliberately producing, feigning, or exaggerating symptoms). Somatic symptom disorder is difficult to diagnose and treat. Some advocates of the diagnosis believe this is because proper diagnosis and treatment requires psychiatrists to work with neurologists on patients with this disorder. Somatic symptom disorders are a group of disorders, all of which fit the definition of physical symptoms similar to those observed in physical disease or injury for which there is no identifiable physical cause. As such, they are a diagnosis of exclusion. Somatic symptoms may be generalized in four major medical categories: neurological, cardiac, pain, and gastrointestinal somatic symptoms. Somatic symptom disorders used to be recognized as Somatoform disorders in the Diagnostic and Statistical Manual of Mental Disorders of the American Psychiatric Association. The following were conditions under the term Somatoform Disorders: