Classifications in psychiatry: a conceptual history

"I was very sad, but not depressed": phenomenological differences between adjustment disorder and a major depressive episode

Introduction

Adjustment disorder (AD) is a diagnosis that must be differentiated from major depressive episode (MDE) because of the therapeutic implications. The aim of this study is to understand the experience of patients who in their lifetime have been diagnosed with AD as well as MDE to establish the characteristics of each disorder.

Methods

A descriptive phenomenological approach was used with in-depth interviews to four patients and the method proposed by Colaizzi to understand the experiences and reach the description of both disorders.

Results

Three women and one man, with advanced schooling were interviewed. The participants emphasized the existence of differences that were grouped in: the attribution made by the individual, the theme of cognitions, the variability in the course, the possibility of mood modulation, the syndrome severity, the presence of hopelessness and the perceived course.

Conclusion

Phenomenological differences were found in the subjective experience of MDE and AD. The MDE would be described as an intense state of generalized shutdown of the subject's own life, with little response to events, and the AD, as a dynamic reaction attributed to a stressful event, with high variability in the course of symptoms due to the dependence on such event, with the preserved hope that it will end.

[Global therapies, local psychiatrists: shock treatment circulation and its implementation in Rosario, Argentina, 1936-1944]

This article analyses the implementation of biological shock treatments in the Psychiatric Institute of Rosario, Argentina, during the interwar period. The aim is to illuminate the impact that a global phenomenon, referred to the strengthening of the discipline and the emergence of new therapies, had on an Argentinean psychiatric care space. Thus, it will analyse the relevance that budgetary limitations, the experimentation of alternatives and the presence of international experts had in the incorporation of therapeutic novelties. It is argued that the strategies deployed by the Institute to implement them expose the local nuances of a global phenomenon, as well as its contribution to the experimentation of treatments.

Conceptual and historical evolution of psychiatric nosology

Psychiatric taxonomies exist within conceptual frameworks which presuppose certain conceptions of psychiatric distress and offer guiding principles. This article provides an overview of the historical development of psychiatric classifications with an emphasis on their methodological assumptions. After identifying roots of scientific psychiatric classifications in the works of Sydenham and Linnaeus and discussing early classification systems, our survey focuses on the Kahlbaum-Hecker-Kraepelin paradigm (with its emphasis on longitudinal course of illness), the Wernicke-Kleist-Leonhard tradition (with its emphasis on neural systems), the development of the ICD and the DSM classifications (with their roots in medical statistics, their pragmatic nature, and their emphasis on descriptive and operationalized criteria), psychodynamic and idiographic perspectives (e.g. the Psychodynamic Diagnostic Manual), and transdiagnostic approaches (e.g. Research Domain Criteria). The central philosophical questions of nosology (descriptive vs aetiological, symptoms vs course of illness, idiographic vs nomothetic, categorical vs dimensional, etc.) have appeared and reappeared throughout this evolution. Ongoing controversies reflect the epistemological and ontological difficulties inherent in defining and classifying mental illness. It may be that no single taxonomy can satisfy all clinical, research, and administrative needs, and that, echoing the ideas of Aubrey Lewis, multiple systems may be required to serve different needs.

"Apples and pears are similar, but still different things." Bipolar disorder and schizophrenia- discrete disorders or just dimensions ?

Starting with the dichotomous view of Kraepelin, schizophrenia and bipolar disorder have traditionally been considered as separate entities. More recent, this taxonomic view of illnesses has been challenged and a continuum psychosis has been postulated based on genetic and neurobiological findings suggestive of a large overlap between disorders. In this paper we will review clinical and experimental data from genetics, morphology, phenomenology and illness progression demonstrating what makes schizophrenia and bipolar disorder different conditions, challenging the idea of the obsolescence of the categorical approach. However, perhaps it is also time to move beyond DSM and search for more refined clinical descriptions that could uncover clinical invariants matching better with molecular data. In the future, computational psychiatry employing artificial intelligence and machine learning might provide us a tool to overcome the gap between clinical descriptions (phenomenology) and neurobiology.

Breaking the web: life beyond the at-risk mental state for psychosis

Psychiatry's most recent foray into the area of risk and prevention has been spear-headed by work on at-risk mental states for psychotic disorders. Twenty-five years' research and clinical application have led us to reformulate the clinical evolution of these syndromes, blurred unhelpful conceptual boundaries between childhood and adult life by adopting a developmental view and has changed the shape of many mental health services as part of a global movement to increase quality. But there are problems: fragmentary psychotic experiences are common in young people but transition from risk-state to full syndrome is uncommon away from specialist clinics with rarefied referrals and can, anyway, be subtle; diagnostic over-shadowing by the prospect of schizophrenia and other psychotic disorders may divert clinical attention from the kaleidoscopic and disabling range of probably treatable psychopathology with which people with risk syndromes present. We use a 19th Century lyric poem, The Lady of Shallot, as an allegory for Psychiatry warning us against regarding these mental states only as pointers towards diagnoses that probably will not occur. Viewed from the fresh perspective of common mental disorders they tell us a great deal about the psychopathological crucible of the second and third decades, the nature of diagnosis, and point towards new treatment paradigms.

A historical account of schizophrenia proneness categories from DSM-I to DSM-5 (1952-2013)

The history of diagnostic classifications in psychiatry has been recognized as a privileged means of access to the vicissitudes inherent to the configuration of a scientific and professional field, also bringing significant contributions to conceptual history. We have taken as primary sources the five editions of the DSM (1952-2013) to examine the construction of diagnostic categories related to schizophrenia proneness, indicating the scientific and social contexts related to the development of DSM and psychiatry itself. Along this process we highlight the conditions of possibility for the emergence of the Attenuated Psychosis Syndrome, a highly controversial diagnostic proposal, in the elaboration of DSM-5. This proposal ended up being rejected not only on scientific grounds, but also because of feared unintended consequences.

Early intervention for incipient insanity: early notions from the 19th century English literature

AIM

Early intervention programmes in mental illnesses started to bloom in the 1990s, and many programmes have been established worldwide during the past twenty years. However, the concept of early intervention has emerged during the 19th century but it did not make much impact on practice. The aim of this review is to identify the difficulties appeared during that period of time which could provide insight into the modern development of early intervention initiatives.

METHODS

A narrative review which focused on English literature about early intervention for insanity during the 19th century was undertaken.

RESULTS

Clinicians during the 19th century recognized that treatment would be the most effective at the early stage of the mental illness and they had emphasized the importance of early intervention. However, because of a number of factors, such as the limited roles of asylums, lack of knowledge about mental disorder and the lack of effective treatment, the idea of early intervention did not make impact in clinical service during that period of time.

CONCLUSION

During the past two hundred years, understanding towards mental illness has advanced and more effective treatments, such as the use of anti-psychotic medications, have been developed. Reflecting on the past experience and difficulties might shed light on the development of today early intervention in mental disorder.

'A more perfect arrangement of plants': the botanical model in psychiatric nosology, 1676 to the present day

Psychiatric classification remains a complex endeavour; since the Enlightenment, nosologists have made use of various models and metaphors to describe their systems. Here we present the most common model, botanical taxonomy, and trace its history from the nosologies of Sydenham, Sauvages and Linnaeus; to evolutionary models; to the later contributions of Hughlings-Jackson, Kraepelin and Jaspers. Over time, there has been a shift from explicit attempts to pattern disease classification on botanical systems, to a more metaphorical use. We find that changes in the understanding of plants and plant relationships parallel changes in the conceptualization of mental illness. Not only have scientific discoveries influenced the use of metaphor, but the language of metaphor has also both illuminated and constrained psychiatric nosology.

Mental illness in Sweden (1896-1905) reflected through case records from a local general hospital

Mental illness in a hospital in a medium-sized town in Sweden was studied. Consecutive case records from 1896 to 1905, and also from 2011, were selected. In the historical sample, neurasthenia was the most common diagnosis, followed by affective disorders and alcohol abuse. ICD-10 diagnoses corresponded well with the historical diagnoses. Melancholia resembled modern criteria for depression. Mania, insania simplex and paranoia indicated more severe illness. Abuse was more common among men and hysteria among women. Those with a medical certificate for mental hospital care were very ill and showed no gender difference. There were no diagnoses for abuse, but 17% had a high level of alcohol consumption. The pattern of signs and symptoms displayed by patients does not appear to change with time.

Realising stratified psychiatry using multidimensional signatures and trajectories

Background

Stratified or personalised medicine targets treatments for groups of individuals with a disorder based on individual heterogeneity and shared factors that influence the likelihood of response. Psychiatry has traditionally defined diagnoses by constellations of co-occurring signs and symptoms that are assigned a categorical label (e.g. schizophrenia). Trial methodology in psychiatry has evaluated interventions targeted at these categorical entities, with diagnoses being equated to disorders. Recent insights into both the nosology and neurobiology of psychiatric disorder reveal that traditional categorical diagnoses cannot be equated with disorders. We argue that current quantitative methodology (1) inherits these categorical assumptions, (2) allows only for the discovery of average treatment response, (3) relies on composite outcome measures and (4) sacrifices valuable predictive information for stratified and personalised treatment in psychiatry.

Methods and findings

To achieve a truly ‘stratified psychiatry’ we propose and then operationalise two necessary steps: first, a formal multi-dimensional representation of disorder definition and clinical state, and second, the similar redefinition of outcomes as multidimensional constructs that can expose within- and between-patient differences in response. We use the categorical diagnosis of schizophrenia—conceptualised as a label for heterogeneous disorders—as a means of introducing operational definitions of stratified psychiatry using principles from multivariate analysis. We demonstrate this framework by application to the Clinical Antipsychotic Trials of Intervention Effectiveness dataset, showing heterogeneity in both patient clinical states and their trajectories after treatment that are lost in the traditional categorical approach with composite outcomes. We then systematically review a decade of registered clinical trials for cognitive deficits in schizophrenia highlighting existing assumptions of categorical diagnoses and aggregate outcomes while identifying a small number of trials that could be reanalysed using our proposal.

Conclusion

We describe quantitative methods for the development of a multi-dimensional model of clinical state, disorders and trajectories which practically realises stratified psychiatry. We highlight the potential for recovering existing trial data, the implications for stratified psychiatry in trial design and clinical treatment and finally, describe different kinds of probabilistic reasoning tools necessary to implement stratification.

Natural kinds, psychiatric classification and the history of the DSM

This paper addresses philosophical issues concerning whether mental disorders are natural kinds and how the DSM should classify mental disorders. I argue that some mental disorders (e.g. schizophrenia, depression) are natural kinds in the sense that they are natural classes constituted by a set of stable biological mechanisms. I subsequently argue that a theoretical and causal approach to classification would provide a method for classifying natural kinds that is superior to the purely descriptive approach adopted by the DSM since DSM-III My argument suggests that the DSM should classify natural kinds in order to provide predictively useful (i.e. projectable) diagnostic categories and that a causal approach to classification would provide a more promising method for formulating valid diagnostic categories.

Psychiatric classification: Current debate and future directions

Classification of health related conditions can be a complex task. This is particularly so in case of psychiatric disorders. The present paper reviews the fundamentals of psychiatric classification, including its basis, history, methods of evaluation, the journey so far and future directions. The various criticisms of current classificatory systems and possible solutions are discussed. Special reference to the research domain criteria (RDoC) approach has been made and implications discussed.

The 'Preliminary Discourse' to Methodical Nosology, by François Boissier de Sauvages (1772)

The eighteenth century witnessed an intense drive to classify diseases as natural kinds. Together with Linné, Macbride, Cullen, Sagar and Vogel, François Boissier de Sauvages, Professor of Medicine at Montpellier, was an important player in this process. In his monumental Nosologie Méthodique, Sauvages based his nosological system on the more botanico view proposed by Thomas Sydenham, namely, that human diseases (including mental ailments) should be classified in the same way as were plants. Classic Text No. 104 is an abridged translation of the Preliminary Discourse to the Nosologie Méthodique.

Psychological symptoms and medical responses in nineteenth-century India

The article documents medical approaches to mental illness in mid- to late-nineteenth-century India through examining the Indian Medical Gazette and other medical accounts. By the late nineteenth century, psychiatry in Europe moved from discussions around asylum-based care to a nuanced and informed debate about the nature of mental symptoms. This included ideas on phrenology and craniometry, biological and psycho-social causes, physical and drug treatments, many of which travelled to India. Simultaneously, indigenous socio-medical ideas were being debated. From the early to the mid-nineteenth century, not much distinction was made between the Western and the native 'mind', and consequently the diagnosis and investigation of mental symptoms did not differ. However, by the late nineteenth century Western medicine considered the 'Western mind' as more civilized and sophisticated than the 'native mind.

What is depression? Psychiatrists' and GPs' experiences of diagnosis and the diagnostic process

The diagnosis of depression is defined by psychiatrists, and guidelines for treatment of patients with depression are created in psychiatry. However, most patients with depression are treated exclusively in general practice. Psychiatrists point out that general practitioners' (GPs') treatment of depression is insufficient and a collaborative care (CC) model between general practice and psychiatry has been proposed to overcome this. However, for successful implementation, a CC model demands shared agreement about the concept of depression and the diagnostic process in the two sectors. We aimed to explore how depression is understood by GPs and clinical psychiatrists. We carried out qualitative in-depth interviews with 11 psychiatrists and 12 GPs. Analysis was made by Interpretative Phenomenological Analysis. We found that the two groups of physicians differed considerably in their views on the usefulness of the concept of depression and in their language and narrative styles when telling stories about depressed patients. The differences were captured in three polarities which expressed the range of experiences in the two groups. Psychiatrists considered the diagnosis of depression as a pragmatic and agreed construct and they did not question its validity. GPs thought depression was a "gray area" and questioned the clinical utility in general practice. Nevertheless, GPs felt a demand from psychiatry to make their diagnosis based on instruments created in psychiatry, whereas psychiatrists based their diagnosis on clinical impression but used instruments to assess severity. GPs were wholly skeptical about instruments which they felt could be misleading. The different understandings could possibly lead to a clash of interests in any proposed CC model. The findings provide fertile ground for organizational research into the actual implementation of cooperation between sectors to explore how differences are dealt with.

Ernst Cassirer's Philosophy of Symbolic Forms and its impact on the theory of psychopathology

The philosopher Ernst Cassirer (1874-1945) wrote in 1929: 'For what it [the philosophy of symbolic forms] is seeking is not so much common factors in being as common factors in meaning. Hence we must strive to bring the teachings of pathology, which cannot be ignored, into the more universal context of the philosophy of culture' (Cassirer, 1955: 275). This statement summarizes his approach in shifting the focus on psychopathological theory from the brain and its localizations to the living interaction between the self and his/her social environment. The present article looks at the impact of symbol theory on psychopathology - pre- and post-Cassirer's main oeuvre Philosophie der symbolischen Formen - and whether his concept still has a role to play in an ontology of psychopathology.

Basing psychiatric classification on scientific foundation: problems and prospects

To examine whether and how the classification of mental disorders can be based on research, we evaluate the relevance of psychiatric science to the major questions in classification. We conclude that most studies cannot inform the validity of diagnostic categories because they are constrained by the classification through a top-down diagnostic approach. Analyses of relationships between diagnostic categories suggest that most interdiagnostic boundaries in current classifications lack validity. Likewise, genetic studies show that the susceptibility to mental illness is at most partly disorder-specific. Neuroimaging research is uninformative due to unsystematic single-diagnosis studies, use of super-healthy controls, and publication bias. Treatment research suggests moderate specificity in several areas of psychopathology (e.g. lithium for bipolar disorder), but lack of specificity is the rule (e.g. the broad indications of serotonin-reuptake inhibitors). In summary, evidence from multiple lines of research converges to indicate that current classifications contain excessively large numbers of categories of limited validity. Dimensional classification will not solve the problem because the number of dimensions is as uncertain as the number of categories. Psychiatric research should discard the assumption that current classification is valid. Instead of diagnosis-specific investigations, studies of unselected groups assessed with bottom-up approaches are needed to advance psychiatry.

Psychiatric diagnoses are not mental processes: Wittgenstein on conceptual confusion

BACKGROUND

Empirical explanation and treatment repeatedly fail for psychiatric diagnoses. Diagnosis is mired in conceptual confusion that is illuminated by Ludwig Wittgenstein's later critique of philosophy (Philosophical Investigations). This paper examines conceptual confusions in the foundation of psychiatric diagnosis from some of Wittgenstein's important critical viewpoints.

ARGUMENT

Diagnostic terms are words whose meanings are given by usages not definitions. Diagnoses, by Wittgenstein's analogy with 'games', have various and evolving usages that are connected by family relationships, and no essence or core phenomenon connects them. Their usages will change according to the demands and contexts in which they are employed. Diagnoses, like many psychological terms, such as 'reading' or 'understanding', are concepts that refer not to fixed behavioural or mental states but to complex apprehensions of the relationship of a variety of behavioural phenomena with the world. A diagnosis is a sort of concept that cannot be located in or explained by a mental process.

CONCLUSION

A diagnosis is an exercise in language and its usage changes according to the context and the needs it addresses. Diagnoses have important uses but they are irreducibly heterogeneous and cannot be identified with or connected to particular mental processes or even with a unity of phenomena that can be addressed empirically. This makes understandable not only the repeated failure of empirical science to replicate or illuminate genetic, neurophysiologic, psychic or social processes underlying diagnoses but also the emptiness of a succession of explanatory theories and treatment effects that cannot be repeated or stubbornly regress to the mean. Attempts to fix the meanings of diagnoses to allow empirical explanation will and should fail as there is no foundation on which a fixed meaning can be built and it can only be done at the cost of the relevance and usefulness of diagnosis.

Confirmation of the factorial structure of temperamental autoquestionnaire TEMPS-A in non-clinical young adults and relation to current state of anxiety, depression and to schizotypal traits

BACKGROUND

The 39-item TEMPS-A self-rated questionnaire assesses affective temperaments. We examined the factorial structure of its French version in a large sample of young adults and examined the relation to schizotypy, depression and anxiety.

METHOD

University students were enrolled during their mandatory preventive health visit in the University medical facility (n = 3807, 19.9 ± 2.5 y.o.). They answered to the 39-TEMPS-A questionnaire, the Schizotypal Personality Questionnaire (SPQ) and the Hospital Anxiety Depression Scale (HADS). We performed an exploratory Factorial Component Analysis (FCA) with varimax rotation of the 39-TEMPS-A in half of the sample, randomly selected, followed by a Confirmatory Factor Analysis (CFA) in the remaining subsample. TEMPS-A dimensions were correlated to HADS and SPQ sub-scores.

RESULTS

A five-factor structure was found by PCA and confirmed by the confirmatory analysis. The scale showed a good internal consistency (whole scale Cronbach's α: 0.83 and from 0.78 to 0.59 for Cyclothymic, Depressive, Irritable, Hyperthymic, Anxious subscales). Depressive and Anxious TEMPS-A subscales were moderately correlated to HADS Depression and Anxiety subscales (Spearman ρ = 0.37 to 0.33). Cyclothymic and Depressive TEMPS-A subscales were respectively correlated to SPQ Paranoid (ρ = 0.53) and Negative dimensions (ρ = 0.52).

LIMITATION

Representativity of the sample (higher education, response rate).

CONCLUSION

We confirmed the five factor structure of the 39-item TEMPS-A in a large non-clinical population of young adults and found consistent correlations with anxiety - depression state markers and schizotypal traits.

Do ideal ascético ao ideal estético: a evolução histórica da Anorexia Nervosa

O estudo da anorexia nervosa sob uma perspectiva histórica visa contribuir para a investigação daquilo que se configura como influência cultural na gênese e manutenção do quadro, além de questionar posições segundo as quais a anorexia nervosa seria um "mal da modernidade" ou decorrente de um único fator. Uma análise da vida das santas da Idade Média, por exemplo, mostra quanto o comportamento perseverante as aproxima das anoréxicas de hoje, ainda que a motivação e os ideais (ascético nas primeiras e estético nas últimas) sejam diferentes.

'On alterations in the form of speech and on the formation of new words and expressions in madness' by L. Snell (1852)

This Classic Text is a translation of an 1852 paper on neologisms and other disorders of language in the insane by Ludwig Snell (1817—92). It illustrates the impact on descriptive psychopathology caused by the early nineteenth-century view that language shaped thought and culture. Developed by Herder, Humboldt and others, this view was to govern the way in which disorders of language were to be studied in psychiatry until well into the twentieth century. After World War II, the so-called ‘cognitive revolution’ returned to the view that thought was more important than language. This encouraged psychiatrists to neglect the study of psychotic neologisms per se and consider ‘thought disorder’ as a primary abnormality in schizophrenia.

Problems with retrospective studies of the presence of schizophrenia

Studies concerning the presence of schizophrenia in the distant past are controversial. Some authors maintain that schizophrenia-like illnesses existed in antiquity, while others argue that this is quite doubtful. Imprecise definition of schizophrenia, imposition of the current concept of schizophrenia onto the past, difficulties in interpreting ancient texts describing schizophrenia-like conditions, and cultural variables involved in the clinical definition of schizophrenia underlie these controversies. This article reviews the methodological issues that arise in such retrospective studies of schizophrenia.

'Essay on a classification of different genera of insanity'. 1853

Less well known than some of his contemporaries, Jules Baillarger (1809—90) tends to be celebrated by `who said it first' writers as the man who assisted the `birth of bipolar disorder'. This view is based on the anachronistic claim that Baillarger's `insanity with a double form', Kraepelin's `das manisch-depressive Irresein', Leonhard's concept of Bipolarität and DSM-IV's `Bipolar I and Bipolar II' Disorder somehow constitute an incremental approximation to the same `disease'. Baillarger is important because he was a high profile conceptual interlocutor in the great 19-century debates on hallucinations, hypochondria, language disorders, General Paralysis of the Insane, cretinism and goitre. Classic Text No. 75 is a translation of Baillarger's important 1853 paper on the classification of madness, and it is a good illustration of the popular method of top-to-bottom psychiatric taxonomy. Written before psychiatrists felt the need to conceal the theoretical nature of the exercise behind a farrago of `empirical evidence', it shows how hidden assumptions govern the way in which the boundaries of mental disorders are actually drawn.

Social determinants of diagnostic labels in depression

The role of diagnostic labels in medicine is usually that of labelling an illness as a means of communication. Control over labelling processes in medicine is ordinarily imposed via medical schools, textbooks, education or by diagnostic manuals. Diagnostic labels often change following new discoveries in underlying pathology such as 'consumption' being relabelled as 'TB' or 'cancer'. Sub-types of broad diagnostic labels also often emerge from such discoveries e.g. 'lung cancer' or 'throat cancer'. In mental health, underlying pathology is the subject of ongoing debate spanning ideas including the brain as a faulty organ, faulty genetics and environmental problems. With controversy over pathology comes controversy over labels and the idea that labels may be used not just for communication, but as devices of social and professional control, arising out of a social process. This study explores the codification of the diagnostic label 'depression' which emerged in the twentieth-century and has proliferated with numerous sub-types over the last 40 years. The aim is to examine its social determinants and context. Medline is used as a data source for professional label usage. A range of depression sub-type labels in professional use was identified. This exercise revealed many official and 'unofficial' terms in professional use. Citation rate plots by year were then generated for these depression sub-type labels. The rise and fall of different labels are examined in relation to social determinants and context, including publication of diagnostic manuals DSM and ICD, power shifts in psychiatry, the discovery of psychiatric drugs and the shift from inpatient to community care. Exploring the changing use of official and unofficial labels over time in this way provides a novel historical perspective on the concept of depression in the late twentieth-century.

The impact of diagnostic criteria on the prevalence of schizophrenic subtypes

The distribution of schizophrenic subtypes shows a high range of cross-cultural and historical variations. Our study aimed to investigate the effect of different diagnostic criteria on the prevalence of schizophrenic subtypes. A sample of 220 consecutively admitted schizophrenic patients from 3 different psychiatric institutions was classified according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, International Statistical Classification of Diseases, 10th Revision, and Bleuler's and Leonhard's criteria. Especially, the frequency of catatonic (10%-22%) and hebephrenic (5%-20%) subtypes of schizophrenia varied within a broad range depending on the diagnostic system applied. The comparison of International Statistical Classification of Diseases, 10th Revision and Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition with "classical" criteria (Bleuler, Leonhard) for the different schizophrenic subtypes showed a reduction of typical symptoms and the introduction of criteria of prominence during the last century. These changes caused 2 trajectories ("paranoidization" and "shift into residual categories") explaining these cross-sectional variations.

Changes in psychiatric diagnoses from admission to discharge: review of the charts of 159 patients consecutively admitted to a geriatric psychiatry inpatient unit

The diagnosis of psychopathology among geriatric acute inpatients requires comprehensive evaluation. To our knowledge, no recently published papers in the geriatric psychiatry literature have systematically examined diagnostic changes during single admissions. We reviewed the charts of 159 patients consecutively admitted to an acute geriatric psychiatry unit over 18 months. We recorded admission diagnoses from initial treatment plans, and discharge diagnoses from discharge summaries. Mean patient age was 80 years and average length of stay was 17 days. The most common primary diagnoses were psychotic and depressive disorders. The most common secondary diagnoses were dementias and depressive disorders. Primary diagnoses changed from admission to discharge in 31 patients (20%), and secondary diagnoses changed in 76 patients (48%). There was a significant change involving the diagnosis of dementia, but not that of depressive or psychotic disorders. A large proportion of inpatients had their diagnoses altered, especially those involving dementias, during hospitalization. Inpatient admission may be valuable for clarifying the diagnoses of elderly psychiatric patients.