The diagnostic category of adjustment disorder (AD) made its first appearance in DSM-III in 1968, replacing the previous “transient situational disturbance” of DSM-II, and shortly after was included in ICD-9. It has persisted into the current versions of both DSM-IV and ICD-10. The inclusion of AD recognizes that people can often develop symptoms or exhibit behaviors in response to stressful events that are in excess of normal reactions. Resolution with the minimum of intervention, apart from general supportive measures, is frequent, either when the stressor is removed, or as new levels of adaptation are reached. Management of anxiety or insomnia symptoms, or brief psychological treatments are sometimes used to shorten the duration or reduce the intensity of AD episodes. In patients with AD, both emotional and behavioral disturbances are present and include low mood, tearfulness, anxiety, self-harm, withdrawal, anger, and irritability.

Definition
AD is defined in DSM-IV as:

. . . emotional or behavioral symptoms in response to an identifiable stressor(s) occurring within 3 months of the onset of the stressor(s). These symptoms or behaviors are clinically significant as evidenced by either . . . marked distress that is in excess of what would be expected from the stressor [or] significant impairment of social or occupational (academic) functioning.

This definition excludes the diagnosis if there is another Axis I or II disorder to which the symptoms may be attributed or if the symptoms are due to bereavement (Table). AD is classified as either acute or chronic, and within each form there are subtypes with depressed mood, with anxiety, with mixed anxiety and depressed mood, with disturbance of conduct, with mixed disturbance of emotions and conduct, and not otherwise specified.

ICD-10 limits the time frame of onset to within 1 month of the causative stressor and, as with DSM-IV, categorizes it as one of exclusion, specifying that the criteria for an affective disorder must not be met. The categories in ICD-10 are brief depressive reaction, prolonged depressive reaction, mixed anxiety and depressive reaction, with predominant disturbance of other emotions, with predominant disturbance of conduct, with mixed disturbance of emotions and conduct, and with other specified predominant symptoms.

While DSM-IV states that the symptoms should resolve within 6 months, it also recognizes a chronic form if exposure to the stressor is long-term or the consequences of exposure to the stressor are prolonged. For example, the loss of a job may lead to the loss of the home, thereby causing marital problems. So the diagnosis can be made even when the index event has resolved or the 6-month time frame has been reached if consequences continue. ICD-10 is silent on the knock-on effect of stressors but allows a 2-year period of symptoms in the prolonged depressive subtype.

Symptoms caused by mood fluctuations in response to day-to-day stressful events that occur in persons with borderline (emotionally unstable) personality disorder are not classified as AD. AD is one of the few psychiatric diagnoses for which the etiology, symptoms, and course, rather than symptoms alone, are central to making the diagnosis.¹

Controversies and dilemmas
A diagnosis of AD raises a number of dilemmas. The first is the distinction from normal reactions to stress, a separation that is important so as not to pathologize the day-to-day travails of life. There is nothing to assist the clinician in making this distinction except that ICD-10 requires both functional impairment and symptoms to make the diagnosis, while DSM requires symptoms or impairment. Thus, ICD is more stringent and has a higher threshold than DSM. Arguably, a decision on whether a reaction is pathological should take account of a number of factors, including:

• Cultural differences in the expression of emotion
• Individual circumstances (eg, the loss of a job may render a person homeless, which is appropriately associated with high levels of distress)
• The mere fact of visiting a doctor or being referred to a mental health professional should not inevitably be regarded as indicative of disorder
• The level of functional impairment as a result of the symptoms (ICD-10 only)

The second dilemma is the differentiation of AD from other Axis I disorders, such as generalized anxiety disorder (GAD) and major depression disorder (MDD). Simply on the basis of symptom numbers and duration of more than 2 weeks, AD would be relabeled as MDD after the time threshold has been crossed, even though the onset of symptoms was temporally close to the stressor. Thus, a young woman with children who had received a diagnosis of stage IV cancer 3 weeks earlier and now has low mood, is not sleeping, is unable to get pleasure from life, has recurrent thoughts of dying, and has poor concentration might variously be thought to be experiencing an appropriate reaction, an AD, or MDD. Examples such as this highlight the need for continued monitoring.

Ordinarily, one would expect the symptoms to resolve when the stressor diminished or was removed. At other times, notwithstanding the persistence of the stressor or its ramifications, the person adapts. A diagnostic conundrum arises, however, when the symptoms and the stressor persist in tandem—is the appropriate diagnosis chronic AD, MDD, or appropriate sadness? In general, normal reactions to events resolve quickly and do not persist, hence, the time frames specified in DSM-IV and ICD-10. A further reason for monitoring is that the symptoms may represent a disorder, such as evolving MDD that emerges more clearly over time.

Another controversy stems from the subsyndromal nature of AD. It may be that allowing MDD to override a diagnosis of AD is a clinical mistake, since there is little to distinguish one from the other in terms of symptoms, although the course of each is different.² In addition, doing so is illogical because the diagnosis of MDD is cross-sectional and is based on symptom numbers and duration; the course of AD is longitudinal and is based on etiology and duration. Thus, MDD and AD represent conceptually different, nonoverlapping dimensions.

This suggests that the current diagnostic system based on symptom thresholds is limited and that in DSM-5 more emphasis should be placed on the specific symptom clusters and their quality. Moreover, the longitudinal course of AD should receive more attention. Since a diagnosis of AD cannot be made at present when the threshold for another condition is met, it is currently regarded as a subsyndromal rather than a full Axis I disorder.1 However, its clinical importance may be such that it should be accorded full syndromal status with its own diagnostic criteria.³

Prevalence
AD is underresearched, and most of the large epidemiological surveys of the general population lack any prevalence data for AD, including the Epidemiological Catchment Area study, the US National Comorbidity Survey, and the National Psychiatric Morbidity surveys of Great Britain.^4-6 As a result, the diagnostic category of AD has not received the attention that it warrants and most of the scientific data are derived from smaller studies made up of particular clinical groups.

The prevalence of AD has been found to be 11% to 18% in primary care.^7,8 In consultation-liaison, where the diagnosis is most often made, the rates are similar: 7.1% to 18.4%.^9-11 This, however, is in a state of flux, and it may be that the “culture of prescription” drives the “culture of diagnosis.”¹ The diagnosis of AD has declined from 28% in 1988 to 14.7% in 1997, while the diagnosis of MDD has increased (6.4% to 14.7%) over the same 10 years.¹²

A major problem in studying AD is the absence of any specific diagnostic criteria with which to make the diagnosis. Instruments such as the Structured Clinical Interview for DSM (SCID) and the Schedules for Clinical Assessment in Neuropsychiatry (SCAN) include the criteria for AD, albeit in a cursory manner. So it is not possible to achieve a gold standard measure based on the current criteria in DSM-IV and ICD-10. For this reason, clinical diagnosis with all its associated problems is the only standard currently available.

Structured diagnostic and screening instruments for AD
Structured interviews are frequently considered the gold standard in psychiatric research because they eliminate the subjective element of the diagnostic process; however, for purposes of diagnosing AD, there are problems. Some of the most widely used structured interviews in research, such as the Clinical Interview Schedule and the Composite International Diagnostic Interview, fail to include AD.^13,14 Others, such as SCID, SCAN, and the Mini International Neuropsychiatric Interview, include AD but regard it as a subsyndromal diagnosis.^15-17 This commonly leads to AD being ignored or conflated with and subsumed by MDD.^2,18