Undifferentiated Somatoform Disorder

Undifferentiated Somatoform Disorder

Definition

As defined in DSM-IV, this category includes disturbances of at least 6 months’ duration, with one or more unintentional, clini-cally significant, medically unexplained physical complaints (see Table 54.1). In a sense, it is a residual category, subsuming syn-dromes with somatic complaints that do not meet criteria for any of the “differentiated” somatoform disorders yet are not better accounted for by any other mental disorder. On the other hand, it is a less residual category than somatoform disorder NOS, in that the disturbance must last at least 6 months (see Figure 54.1). Vir-tually any unintentional, medically unexplained physical symp-toms causing clinically significant distress or impairment can be considered. In effect, this category serves to capture syndromes that resemble somatization disorder but do not meet full criteria.

Epidemiology

Some have argued that undifferentiated somatoform disorder is the most common somatoform disorder. Escobar and coworkers (1991), using an abridged somatization disorder construct requir-ing six somatic symptoms for women and four for men, reported that 11% of nonHispanic US whites and Hispanics, 15% of US blacks and 20% of Puerto Ricans in Puerto Rico fulfilled criteria. A preponderance of women was evident in all groups except the Puerto Rican sample (see Table 54.1). According to Escobar, such an abridged somatoform syndrome is 100 times more prevalent than a full somatoform syndrome

Diagnosis and Differential Diagnosis

In comparison to when the full criteria for the well-validated so-matization disorder are met, exclusion of an as yet undiscovered general medical or substance-induced explanation for physical symptoms is far less certain when the less stringent criteria for undifferentiated somatoform disorder are met. Thus, the diagno-sis of undifferentiated somatoform disorder should remain tenta-tive, and new symptoms should be carefully investigated.

Because undifferentiated somatoform disorder represents somewhat of a residual category, the major diagnostic process, once occult general medical conditions and substance-induced explanations have been considered, is one of exclusion. As shown in Figure 54.1, whether the somatic symptoms are intentionally produced as in malingering and factitious disorder must be ad-dressed. Here, motivation for external rewards (for malingering) and a pervasive intent to assume the sick role (for factitious dis-order) must be assessed. The next consideration is whether the somatic symptoms are the manifestation of another psychiatric disorder. Anxiety and mood disorders commonly present with somatic symptoms; high rates of anxiety and major depressive disorders are reported in patients with somatic complaints at-tending family medicine clinics. Of course, undifferentiated somatoform disorder could be diagnosed in addition to one of these disorders, so long as the symptoms are not accounted for by the other psychiatric disorder. Crucial in this determination is whether the symptoms are present during periods in which the anxiety or mood disorders are not actively present.

Next, other somatoform disorders must be considered. In general, undifferentiated somatoform disorders are characterized by unexplained somatic complaints; the most common accord-ing to Escobar and coworkers (Escobar et al., 1989) are female reproductive symptoms, excessive gas, abdominal pain, chest pain, joint pain, palpitations and fainting, rather than preoccupa-tions or fears as in hypochondriasis or body dysmorphic disor-der. However, a patient with some manifestations of these two disorders but not meeting full criteria could conceivably receive a diagnosis of undifferentiated somatoform disorder. An exam-ple is a patient with recurrent yet shifting hypochondriacal con-cerns that do respond to medical reassurance. If symptoms are restricted to those affecting the domains of sexual dysfunction, pain, or pseudoneurological symptoms, and the specific criteria for a sexual dysfunction, pain disorder and/or conversion disor-der are met, the specific disorder or disorders should be diag-nosed. If other types of symptoms or symptoms of more than one of these disorders have been present for at least 6 months, yet criteria for somatization disorder are not met, undifferentiated somatoform disorder should be diagnosed. By definition, undif-ferentiated somatoform disorder requires a duration of 6 months. If this criterion is not met, a diagnosis of somatoform disorder NOS should be considered.

Patients with an apparent undifferentiated somatoform disorder should be carefully evaluated for somatization disorder. Typically, patients with somatization disorder are inconsistent his-torians, at one evaluation reporting a large number of symptoms fulfilling criteria for the full syndrome, at another time endorsing fewer symptoms. In addition, with follow-up, additional symp-toms may become evident, and criteria for somatization disorder will be satisfied. Patients with multiple somatic complaints not diagnosed with somatization disorder because of a reported onset later than 30 years of age may be inaccurately reporting a later age at onset. If the late age at onset is accurate, the patient should be carefully scrutinized for an occult general medical disorder.

In addition to the range of symptoms specified in the other somatoform disorders, patients complaining primarily of fatigue (chronic fatigue syndrome), bowel problems (irritable bowel syn-drome), or multiple muscle aches/weakness (fibromylagia) can be considered for undifferentiated somatoform disorder. Substantial controversy exists regarding the etiology of such syndromes. Even if an explanation on the basis of a known pathophysiological mechanism cannot be established, many argue that the syndromes should be considered general medical conditions. However, for the time being, these syndromes could be considered in a highly tentative manner under the undifferentiated somatoform disorder rubric. Careful reconsideration of the psychiatric label should be undertaken at regular intervals if the symptoms persist. The psy-chiatrist should remain ever vigilant to the emergence of another general medical or psychiatric condition. When patients are di-agnosed with chronic fatigue syndrome, careful evaluation pro-cedures are recommended.

Course, Natural History and Prognosis

As shown in Table 54.1, it appears that the course and prognosis of undifferentiated somatoform disorder are highly variable. This is not surprising, because the definition of this disorder allows a great deal of heterogeneity.

Treatment

In view of the broad inclusion and minimal exclusion criteria for undifferentiated somatoform disorder, it is difficult to make treat-ment recommendations beyond the generic guidelines outlined for the somatoform disorders in general. More definitive recom-mendations await a more extensive empirical database. A sub-stantial proportion of patients with undifferentiated somatoform disorders improve or recover with no formal therapy. However, appropriate psychotherapy and pharmacological intervention may accelerate the process.

Some recommendations for patients with symptoms of headache, fibromyalgia, and chronic fatigue syndrome, condi-tions that some would include under undifferentiated somatoform disorder. Generally recommended are brief psychotherapy of a supportive and educative nature. As with somatization disorder, the physician–patient relationship is of great importance. Judi-cious use of pharmacotherapy may also be of benefit, particularly if the somatoform syndrome is intertwined with an anxiety or depressive syndrome. Here, usual antianxiety and antidepressant medications are recommended. Patients with unexplained pains may benefit from pain management strategies as outlined in the pain disorder section.