The psychiatric diagnoses that arise between normal behaviour and major psychiatric morbidities constitute the problematic subthreshold disorders. These subthreshold entities are also juxtaposed between problem-level diagnoses and more clearly defined disorders. Adjustment disorder (AD) would ‘trump’ problem-level disorders, but would be ‘trumped’ by a specific diagnosis even if it were in the NOS category. The subthreshold disorders present major taxonomical and diagnostic dilemmas in that they are often poorly defined, overlap with other diagnostic groupings, and have indefinite symptomatology. It is therefore not surprising that issues of reliability and validity prevail. One of the most commonly employed subthreshold diagnosis that has undergone a major evolution since 1952 is AD (Table 4.6.4.1). The advantage of the indefiniteness of these subthreshold disorders is that they permit the classification of early or prodromal states when the clinical picture is vague and indistinct, and yet the morbid state is in excess of that expected in a normal reaction and this morbidity needs to be identified and often treated. Therefore, AD has an essential place in the psychiatric taxonomy. Many questions prevail with regard to the concept of the AD diagnosis: (1) the role of stressors and the place of specific stressors; (2) the importance of age; (3) the role of concurrent medical morbidity, for example comorbidity of Axis I and/or Axis III disorders; (4) the lack of specificity of the diagnostic criteria; (5) the absence of a symptom checklist; (6) uncertainty as to optimal treatment protocols; and (7) undocumented prognosis or outcomes. Research data regarding these questions will be examined. The DSM was conceptually designed with an atheoretical framework to encourage psychiatric diagnoses to be derived on phenomenological grounds with an avowed dismissal of pathogenesis or aetiology as diagnostic imperatives. In frank contradiction to this atheoretical conceptual framework, the stress-induced disorders require the inclusion of an aetiological significance to a life event—a stressor—and the need to relate the stressor's effect on the patient in clinical terms. However, the stress-related disorders are unique in that they are psychiatric diagnoses with a known aetiology—the stressor—and thus aetiology is essential for the diagnosis. Four other diagnostic categories also invoke aetiology in their diagnostic criteria: (1) organic mental disorders (aetiology-physical abnormality); (2) substance abuse disorders (aetiology-ingestion of substances); (3) post-traumatic; and (4) acute stress disorders AD is a stress-related phenomenon in which the stressor precipitates maladaptation and symptoms that are time limited until either the stressor is diminished or eliminated, or a new state of adaptation to the stressor occurs (Table 4.6.4.2). At the same time that AD was evolving, other stress-related disorders, for example, post-traumatic stress disorder and acute stress disorder were described. (Acute stress disorder was formulated by Spiegel during the development of the DSM-IV. Acute stress reactions could result from involvement in a natural disaster such as a flood, or an avalanche, or a cataclysmic personal event, for example, loss of a body part (aetiology-an identifiable stressor). The diagnosis of AD also requires a careful titration of the timing of the stressor in relation to the adverse psychological sequelae that ensue. Maladaptation and disturbance of mood should occur within 3 months of the patient experiencing the stressor. Until the DSM-IV criteria, the ADs were regarded as transitory diagnoses that should not exceed 6 months in duration. Thereafter, that diagnostic appellation could not be employed and had to be changed to a major psychiatric disorder or discontinued.
