Objective: Contemporary psychiatric classifications have not proved to be useful in the understanding and care of people with physical illness. Distress syndromes are common, but classifications fail to differentiate syndromes relevantly. We sought to take a fresh look at the common distress syndromes in the medically ill. Methods: 312 medical inpatients were interviewed using a structured psychiatric interview [the Monash Interview for Liaison Psychiatry (MILP)] to elicit the presence of mood, anxiety and somatoform symptoms. A previously reported examination of these data using latent trait analysis revealed the dimensions of demoralization, anhedonia, autonomic anxiety, somatoform symptoms and grief. Patients were scored on these dimensions and, on the basis of these, subjected to cluster analysis. Derived classes were compared on a range of demographic and clinical data including psychiatric diagnosis. Results: Six classes were found, distinguished by general levels of distress (measured by demoralization, autonomic anxiety and somatoform symptoms), anhedonia and grief. The most distressed groups were Demoralization and Demoralized Grief. Anhedonic Depression showed moderate levels of distress but the highest level of social dysfunction. Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) categories of mood disorders did not follow any particular pattern other than reflecting severity of distress. The classes of high distress (Demoralization and Demoralized Grief) were significantly associated with younger age, past history of psychiatric treatment, low Global Assessment of Functioning (GAF) scores over the previous 12 months and DSM-IV somatoform disorders. Patients with Demoralized Grief tended to acknowledge their illness as a significant and relevant stressor. Patients with Demoralization identified other stressors as significant. Conclusion: Concepts of demoralization, anhedonia and grief differentiate between important clinical syndromes and have informed the development of a taxonomy of common distress syndromes in the medically ill. Research is required to further explore the validity and utility of these concepts.
The development of diagnostic classifications using operationalised criteria, as exemplified by the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) [1] and the International Classification of Diseases (ICD-10) [2], has undoubtedly had a major impact on psychiatry. It has provided reliability of diagnosis, a common language for psychiatrists and a focus for research. However, as the early developers knew, the validity of such diagnostic systems would need to be tested [3]. Within the clinical area of consultation-liaison psychiatry—that is, in the situation of the presence of comorbid physical illness, there is a considerable body of literature highlighting the inability of these diagnostic systems to describe adequately the nature, range and aetiological understandings of the phenomena seen [4] and [5]. An important example is the diagnosis of depression where there is a high prevalence in this population but a lack of differentiation of syndromes within the depressive spectrum [6], [7] and [8]. Although grades of severity of depression are recognised, there is little meaningful subtyping [9] and [10]. Furthermore, depressive symptoms frequently coexist with anxiety and somatic symptoms [11]. As van Praag [12] suggests, “syndromal differentiation has disappeared from the diagnosis of depression” (p. 767).
This difficulty in applying a standard psychiatric classification to the consultation-liaison setting is an example of “category fallacy” (to borrow a term from the transcultural literature) where a restrictive diagnostic template developed in one population is used in another culture “for whom it lacks coherence and its validity has not been established” [13,p.452]. Upon this background, we decided to embark on a fresh examination of the psychopathology of patients presenting with physical illness, and specifically of the affective and somatic expressions, with a view of developing a more relevant taxonomy.
There are several steps in developing a classification. We have followed Paykel's [14] advice: “first to group symptoms into syndromes and then to group individuals with syndromes into diagnostic categories” (p. 357). In the absence of a “gold standard” [15], we used latent trait analysis (as employed by Goldberg et al. [16] and Ormel et al. [17]) to examine the dimensional structure of the symptom data and a cluster analytic technique for the second stage of grouping individuals. The latent trait analysis identified five dimensions, which we named demoralization, anhedonia, autonomic anxiety, somatoform symptoms and grief, and has been reported previously [18]. This paper describes the second stage, involving a cluster analysis of subjects, and a comparison of the derived classes with standard DSM-IV diagnoses, demographic and clinical data.
