Heterogeneity of cycloid psychoses: a latent class analysis

Historical and conceptual features of acute polymorphic psychosis: a myth of European psychiatry from bouffée délirante to ICD-11 acute and transient psychotic disorder

This paper deals with the history and epistemology of acute polymorphic psychosis. We undertook a comparative study of short-lived psychotic disorders used in different European countries since the late nineteenth century. The theory of degeneration offered a speculative basis to conceptualization of conditions such as bouffée délirante, cycloid psychosis and reactive psychosis, but it seems likely that different factors contributed to the profusion of clinical concepts with adverse effects on both nomenclature and classification. The resulting picture suggests that earlier nosological concepts tend to converge on common descriptive features and challenge the diagnostic categories for short-lived psychotic disorders listed in modern symptom-based psychiatric classifications.

A neuropsychological study on Leonhard's nosological system

Phenotype validation of endogenous psychosis is a problem that remains to be solved. This study investigated the neuropsychological performance of endogenous psychosis subtypes according to Wernicke-Kleist-Leonhard's classification system (WKL). The participants included consecutive admissions of patients with schizophrenia spectrum disorder or mood disorder with psychotic symptoms (N = 98) and healthy comparison subjects (N = 50). The patients were assessed by means of semi-structured interviews and diagnosed through the WKL system into three groups: a manic-depressive illness and cycloid psychosis group (MDC), unsystematic schizophrenia (USch) and systematic schizophrenia (SSch). All the participants completed a comprehensive neuropsychological battery. The three Leonhard's psychosis subtypes showed a common neuropsychological profile with differences in the severity of impairment relative to healthy controls. MDC patients showed better performance on premorbid intelligence, verbal memory and global cognitive index than USch and SSch patients, and they showed better performance on processing speed, and working memory than SSch patients. USch patients outperformed SSch patients in verbal memory, working memory and global cognitive index. Neuropsychological performance showed a modest accuracy for classification into the WKL nosology. Our results suggest the existence of a common profile of cognitive impairment cutting across WKL subtypes of endogenous psychosis but with significant differences on a severity continuum. In addition, classification accuracy in the three WKL subtypes by means of neuropsychological performance was modest, ranging between 40 and 64% of correctly classified patients.

Cycloid Psychosis Comorbid with Prader-Willi Syndrome: A Case Series

Psychosis is a relatively common psychiatric phenomenon seen in patients with Prader-Willi Syndrome (PWS). However, the presentation is atypical and difficult to classify within currently defined affective or psychotic disorders. This distinct presentation may be better understood as a phenomenon called "cycloid psychosis," described as an episodic psychosis with rapid full recovery between episodes. This study retrospectively analyzed the cases of 12 patients with genetically confirmed PWS who presented to an ambulatory psychiatric center for a change in behavior consistent with psychosis. Each case was then assessed for symptoms of cycloid psychosis, bipolar disorder, depression with psychotic features, schizophrenia, and schizoaffective disorder. Out of the 12 patients, 11 (91.7%) met the currently described diagnostic criteria for cycloid psychosis. Of the 12 patients, 7 (58.3%) also met the diagnostic criteria for bipolar disorder, and 1 (8.3%) also met the diagnostic criteria for schizoaffective disorder. None of the patients met the criteria for schizophrenia or depression with psychotic features. The findings in this study suggest that cycloid psychosis and bipolar disorder may both be comorbid with PWS. Psychiatric comorbidities in patients with PWS are atypical and clinicians should be aware of conditions such as cycloid psychosis when managing this vulnerable population.

Nonaffective acute psychoses: uncertainties on the way to DSM-V and ICD-11

Since the early 20th century, a group of nonaffective psychoses with acute onset and brief duration have been described in different countries under various names, including cycloid psychosis, bouffée délirante, and reactive psychosis. These psychoses share several characteristics, including benign course, greater prevalence in women than men and in developing countries than in industrialized countries, and high prevalence of premorbid psychological and physiologic stressors. However, the variations in names and minute details of symptomatology have overshadowed the basic similarities across these various descriptions. Confusion in classification persists in the two contemporary diagnostic systems, the DSM-IV and the ICD-10. We believe that most cases of these psychoses could be captured under a broad, unified category of nonaffective psychosis with acute onset and brief duration, and urge the authors of the upcoming revisions of the DSM and ICD to create such a category. A unified diagnostic category for these disorders would reduce unnecessary fragmentation in the diagnostic systems and assist in the progress of research on these rare conditions.

Seeking verisimilitude in a class: a systematic review of evidence that the criterial clinical symptoms of schizophrenia are taxonic

This review examines whether there is evidence that the criterion symptoms of Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) (DSM-IV) schizophrenia are taxonic--that schizophrenia is not part of a single distribution of normality. Two taxometric methods, coherent cut kinetics (CCK) and latent variable modeling (LVM), are demonstrated to be sensitive to latent classes and, therefore, were regarded as providing relevant statistical evidence. A systematic literature search identified 24 articles describing analyses of 28 participant cohorts in which CCK or LVM methods were used with one or more criterion symptoms of schizophrenia. Virtually all analyses yielded results that, on first impression, favored taxonic over dimensional interpretations of the latent structure of schizophrenia. However, threats to the internal and external validity of these studies--including biased or inadequate analyses, violation of statistical assumptions, inadequate indicator screening, and the introduction of systematic error through recruitment and sampling--critically undermine this body of work. Uncertainties about the potential effects of perceptual biases, unimodal assessment, and item parceling are also identified, as are limitations in seeking to validate classes with single or double dissociations of outcomes. We conclude that there is no reason to seriously doubt a single-distribution model of schizophrenia because there is no evidence that provides a serious test of this null hypothesis. A second fundamental question remains outstanding: is schizophrenia truly a group of schizophrenias, with taxonic divisions separating its types? We make design and analysis suggestions for future research addressing these questions.

Acute and transient psychotic disorders (ICD-10 F23): a review from a European perspective

The tenth revision of the International Classification of Mental and Behavioural Disorders (ICD-10) introduced the category F23 'Acute and transient psychotic disorders' (ATPD) to incorporate clinical concepts such as the French bouffée délirante, cycloid psychosis (Germany), and the Scandinavian reactive and schizophreniform psychoses. The aim of this paper is to review the literature on ATPD and to examine how it has been differentiated from the other categories of F2 group 'schizophrenia and related disorders'. Papers published between 1993 and 2007 were found through searches in Medline, PsychInfo and Google Scholar. Further references were identified from book chapters and comprehensive reviews of the topic. ATPD is reported as being prevalent in females and as having onset in early-middle adulthood. Although follow-up studies suggest that its outcome is more favourable than other disorders in the F2 group, ATPD tends to recur and half of cases convert mainly into either schizophrenia or affective disorders. No evidence supports the view that the traditional conditions subsumed under ATPD all refer to this diagnostic category. The lack of defining features and poor prognostic validity argue against the separation of ATPD from borderland categories.

Cycloid psychoses revisited: case reports, literature review, and commentary

Emil Kraepelin proposed to separate psychiatric disorders with psychotic features into two major categories, dementia praecox (later schizophrenia) and manic-depressive insanity (later bipolar disorder and major depression). Over the past century, there have been many efforts to categorize conditions that do not fit readily in either group. These conditions include many cases of acute psychotic illnesses of limited duration, with recovery between recurrences. For some of these conditions, Karl Kleist proposed the term cycloid psychosis: acute features were psychotic, as in schizophrenia, but the course was episodic, as in manic-depression. His concept was later elaborated by Karl Leonhard and Carlo Perris, and validated by modern studies. Leonhard described three overlapping cycloid subtypes (anxiety-beatific, excited-inhibited confusional, and hyperkinetic-akinetic motility dysfunction forms); Perris proposed a more unitary syndrome with operational diagnostic criteria; and recent investigators have considered relatively affective versus thought-disordered subtypes. The cycloid concept is not explicitly included in standard international diagnostic schemes, but both DSM-IV and ICD-10 have broad categories for acute, recurrent psychotic disorders, whose validity remains insecure. We present two cases of probable cycloid psychosis, review the history of the concept, and propose that it be reconsidered as a clinically useful category whose validity and utility for prognosis and treatment can be further tested.

Major psychoses with mixed psychotic and mood symptoms: are mixed psychoses associated with different neurobiological markers?

OBJECTIVE

Evidence related to overlapping clinical and genetic risk factors in schizophrenia and bipolar disorder (BD) have raised concerns about the validity of 'Kraepelinian dichotomy'. As controversies mainly arise in mixed psychoses that occupy the intermediate zone between schizophrenia and BD, investigating neurobiological markers of mixed psychoses may be relevant to understanding the nature of psychotic disorders.

METHOD

In this article, we review studies comparing magnetic resonance imaging, neuropsychological and electrophysiological findings in mixed psychoses with each other, as well as with more prototypical cases of schizophrenia and BD.

RESULTS

The evidence reviewed suggests that mixed psychoses may be associated with different genetic and neurobiological markers compared with prototypical forms of schizophrenia and BD.

CONCLUSION

These findings may be compatible with more sophisticated versions of dimensional and continuum models or, alternatively, they may suggest that there is an intermediate third category between prototypical schizophrenia and BD.

Cycloid psychosis: an examination of the validity of the concept

The diagnosis of cycloid psychosis has a long tradition in European psychiatry. However, it has been poorly assimilated within the DSM IV and ICD-10 diagnostic systems. Leonhard set the basis for the current conceptualization of the disorder, and Perris and Brockington developed the first operational diagnostic criteria. However, the two conceptualizations of the disorder are not the same and differ across a number of meaningful variables. Cycloid psychosis is a useful concept in that it possesses both clinical and predictive validity. Despite the high prevalence of mood symptoms and syndromes, cycloid psychosis does not equal schizoaffective disorder. Although a substantial body of evidence suggests that cycloid psychosis differs meaningfully from typical schizophrenia, it is less clear whether it differs from major mood disorders or represents an independent nosological entity. The existence of putative subtypes is also likely, and the differentiation between affective and nonaffective subtypes has received some support.

Sind zykloide Psychosen atypische manisch-depressive Erkrankungen?

BACKGROUND

Whereas a growing body of evidence suggests that cycloid psychoses have to be separated from schizophrenic psychoses, their relations to bipolar affective disorder are less clear.

PATIENTS AND METHODS

In a controlled family study, we recruited 46 patients with cycloid psychosis (CP), 33 with manic-depressive illness (MDI), and 27 controls. Three hundred fifty-six of 389 living first-degree relatives were personally examined by experienced psychiatrists blinded to the diagnosis of the index proband.

RESULTS

The relatives of CP patients showed significantly lower morbidity risk of functional psychoses than relatives of patients with MDI in Kaplan-Meier life table calculation. The morbidity risk for functional psychoses in relatives of patients with CP did not differ significantly from that in relatives of controls.

CONCLUSION

These results suggest that CP are etiologically different from bipolar affective psychoses and cannot be integrated into the spectrum of bipolar affective disorders. The findings provide further evidence for a nosological independence of CP.

Cycloid psychosis

This article reviews the concept, nosological status, diagnostic features, associated clinical characteristics, and the etiopathological variables involved in cycloid psychosis. The concept of cycloid psychosis is based on sound psychopathological and course underpinnings, and despite the inclusion of some cycloid features in the current diagnostic systems such as ICD-10 and DSM-IV, these systems do not capture well the diagnostic construct of this disorder. Cycloid psychosis is a valid clinical constructs that can be easily differentiated from the boundary disorders on clinical grounds. It seems to be heterogeneous from the etiopathological point of view, in that a variety of factors seems to be involved to a different degree in most of the patients. Future studies should examine putative subtypes of the disorder in relation to etiological, pathophysiological and clinical variables.

Cycloid psychoses are not part of a bipolar affective spectrum: results of a controlled family study

BACKGROUND

Whereas a growing body of evidence suggests that cycloid psychoses have to be separated from schizophrenic psychoses, their relations to bipolar affective disorder are less clear. To further clarify this issue a controlled family study was undertaken.

METHODS

All living and traceable adult first-degree relatives of 45 cycloid psychotic, 32 manic-depressive and 27 control probands were personally examined by an experienced psychiatrist blind to the diagnosis of the index proband. Data about not traceable relatives were collected by the "Family-History"-Method. A catamnestic diagnosis was established for each of the 431 relatives blind to family data. Age-corrected morbidity risks were calculated using the life-table method.

RESULTS

Relatives of cycloid psychotic patients showed a significantly lower morbidity risk for endogenous psychoses in general and manic-depressive illness compared to relatives of patients with manic-depressive illness. The familial morbidity risk for cycloid psychoses was low and did not differ significantly in both proband groups. Relatives of cycloid psychotic patients however did not differ significantly from relatives of controls regarding familial morbidity.

LIMITATIONS

Our time-consuming methodical procedure implicated a relatively small number of participants due to restricted personnel resources. The restriction to hospitalised probands could possibly cause a limited representativity of the study sample.

CONCLUSIONS

Our results suggest that cycloid psychoses are aetiologically different from manic-depressive illness and could not be integrated into a spectrum of bipolar affective disorders. The findings provide further evidence for a nosological independence of cycloid psychoses.

Nonschizophrenic psychotic disorders: the case of cycloid psychoses

BACKGROUND

Cycloid psychosis is a psychiatric disorder known for about 100 years. This disorder is at present partly and simplified represented in the ICD-10.

SAMPLING AND METHODS

Over a period of 15 months, 139 consecutively acutely admitted psychotic patients were assessed, by means of different diagnostic instruments, in order to investigate the prevalence and the symptom profile of cycloid psychoses. In addition, the concordance between the diagnoses cycloid psychosis, brief psychotic disorder, and acute polymorphic psychotic disorder with or without symptoms of schizophrenia was calculated.

RESULTS

Cycloid psychoses were present in 13% of the patients. There was a significant but small overlap with the DSM brief psychotic disorder and the ICD acute polymorphic psychotic disorder.

CONCLUSIONS

This study demonstrates that cycloid psychoses can be identified with the proper diagnostic instruments in a proportion that is also found in other studies. Since this type of psychosis entails a distinct prognosis and may require a specific treatment, its identification is of clinical importance. Limitations are the nature of the psychiatric facility with an inherent bias in the selection of patients and the lack of a long-term evaluation.

Distinguishing between first-admission schizophreniform disorder and schizophrenia

BACKGROUND

The validity of schizophreniform disorder remains controversial. Past research suggests that cases of schizophreniform disorder may be: (1). atypical cases of affective disorders, (2). cases of schizophrenia in early course, or (3). a heterogeneous group of disorders including a subgroup with benign course and outcome which maintains this diagnosis in the long term.

METHOD

We tested the validity of the schizophreniform disorder diagnosis by comparing the socio-demographic and baseline clinical characteristics, 24-month course and outcome, and 6- and 24-month research diagnoses of 34 cases initially diagnosed with schizophreniform disorder, and 128 cases with schizophrenia, drawn from a cohort of 628 first-admission patients in the Suffolk County Mental Health Project.

RESULTS

Compared to patients with schizophrenia, those with schizophreniform disorder were more likely to remit fully by 6 months and retain this status by 24 months. Only about half of the patients with schizophreniform disorder were re-diagnosed with schizophrenia or schizoaffective disorder at 24-month follow-up, 13% were re-diagnosed with affective disorders and 19% retained the diagnosis of schizophreniform disorder. In contrast, 92% of cases with a baseline diagnosis of schizophrenia retained this diagnosis at 24-month follow-up. The findings were similar in comparisons with schizophrenia patients having onset of symptoms within 6 months of hospitalization.

CONCLUSIONS

Schizophreniform disorder is a heterogeneous category, which includes a small group with benign psychotic disorders who maintain this diagnosis over at least 24 months. Better delineation of this subgroup has important treatment implications.