Mortality and causes of death of acute and transient psychotic disorders

Mortality in Qatari individuals with mental illness: a retrospective cohort study

INTRODUCTION

There is substantial evidence that people with mental illness have higher mortality rates than the general population. However, most of the studies were from Western countries, and it is not clear whether this finding also applies to Arab countries like Qatar.

OBJECTIVES

We aimed to explore whether mortality in patients with mental illness in Qatar, is different from those without.

METHODS

We conducted a retrospective cohort study, including all Qatari nationals deceased in 2017 and 2018, using the list of registered deaths from Hamad Medical Corporation (HMC) Mortuary. We divided the cohort of deceased people into two groups: with and without mental illness. For each of the groups, we collected the age at death, the reported cause of death as well as sociodemographic and clinical data.

RESULTS

There were 602 registered deaths in 2017 and 589 deaths in 2018. The prevalence of mental illness was 20.4%. Compared to subjects without mental illness, subjects with mental illness surprisingly had higher age at death (median ± IQR = 76.5 ± 22.1 years vs. 62.7 ± 32.9 years; p < .001). This difference persisted even after we controlled for covariates. Individuals with mental illness were more likely to die of an infection (OR = 1.98[1.44;2.71]), or of chronic respiratory disease (OR = 3.53 [1.66;7.52]) but less likely to die because of accidental (OR = 0.21[0.09;0.49]) or congenital causes (OR = 0.18[0.04;0.77]).

CONCLUSION

Contrary to most previous studies, we did not find that mortality was higher in Qatari individuals with mental illness. Sociocultural factors, free and easy-to-access healthcare, and an enhanced role of mental health professionals in detecting medical comorbidities may explain this finding.

Suicidal behavior across a broad range of psychiatric disorders

Suicide is a leading cause of death worldwide. In 2020, some 12.2 million Americans seriously contemplated suicide, 3.2 million planned suicide attempts, and 1.2 million attempted suicide. Traditionally, the approach to treating suicidal behavior (SB) has been to treat the "underlying" psychiatric disorder. However, the number of diagnoses associated with SB is considerable. We could find no studies describing the range of disorders reported to be comorbid with SB. This narrative review summarizes literature documenting the occurrence of SB across the lifespan and the full range of psychiatric diagnoses, not only BPD and those that comprise MDE, It also describes the relevance of these observations to clinical practice, research, and nosology. The literature searches contained the terms "suicid*" and each individual psychiatric diagnosis and identified 587 studies. We did not include case reports, case series, studies only addressing suicidal ideation or non-suicidal self-injury (NSSI), studies on self-harm, not distinguishing between SB and NSSI and studies that did not include any individuals that met criteria for a specific DSM-5 diagnosis (n = 366). We found that SB (suicide and/or suicide attempt) was reported to be associated with 72 out of 145 diagnoses, although data quality varied. Thus, SB is not exclusively germane to Major Depressive Episode (MDE) and Borderline Personality Disorder (BPD), the only conditions for which it is a diagnostic criterion. That SB co-occurs with so many diagnoses reinforces the need to assess current and past SB regardless of diagnosis, and supports the addition of charting codes to the DSM-5 to indicate current or past SB. It also comports with new data that specific genes are associated with SB independent of psychiatric diagnoses, and suggests that SB should be managed with specific suicide prevention interventions in addition to treatments indicated for co-occurring diagnoses. SB diagnostic codes would help researchers and clinicians document and measure SB's trajectory and response to treatment over time, and, ultimately, help develop secondary and tertiary prevention strategies. As a separate diagnosis, SB would preclude situations in which a potentially life-threatening behavior is not accounted for by a diagnosis, a problem that is particularly salient when no mental disorder is present, as is sometimes the case.

Predictors of diagnostic stability in acute and transient psychotic disorders: validation of previous findings and implications for ICD-11

Acute and transient psychotic disorders (ATPD) have moderate prospective diagnostic stability. Female gender, older age at onset, good premorbid adjustment, abrupt onset, shifting polymorphic symptomatology and absence of schizophrenic features have been found to be predictive factors of diagnostic stability in ATPDs. Nevertheless, most of these findings need to be replicated. The purpose of this study was to evaluate the diagnostic stability of patients with ATPD, and to determine whether previously accepted predictors of diagnostic stability for ATPD could be externally validated in our cohort. To that end, a prospective 2-year observational study was conducted on patients with first-episode ATPD. Multivariate analysis was performed to determine factors associated with ATPD diagnostic stability at the end of the follow-up period. The following prior knowledge variables were analyzed: female gender, older age at onset, good premorbid adjustment, abrupt onset, shifting polymorphic symptomatology and absence of schizophrenic features. Sixty-eight patients with first-episode ATPD completed the follow-up, of whom 55.9% (n = 38) retained their diagnosis of ATPD at the end of the study. Multivariate analysis revealed that diagnostic stability was independently significantly associated with the presence of shifting polymorphic symptomatology (OR = 7.42, 95% CI 1.65-33.30; p = 0.009) and the absence of schizophrenic features (OR = 6.37, 95% CI 1.47-27.54; p = 0.013) at the onset of the psychotic disorder. Our findings provide empirical support for the ICD-11 proposal restricting the new ATPD category to the acute polymorphic disorder without schizophrenia symptoms.

The prognostic role of catatonia, hallucinations, and symptoms of schizophrenia in acute and transient psychosis

OBJECTIVES

To examine the prospective temporal stability of acute and transient psychotic disorders (ATPDs) and analyze whether there are clinical, psychopathological, or sociodemographic characteristics that predict ATPD diagnostic stability.

METHOD

We conducted a prospective, 2-year, observational study of patients presenting a first-episode ATPD. A multivariate logistic regression model was developed to identify independent variables associated with ATPD diagnostic stability. Well-established predictive factors of diagnostic stability, as well as all the psychopathological features included in the ICD-10 Diagnostic Criteria for Research (DCR) descriptions of ATPD, were analyzed.

RESULTS

Sixty-eight patients with a first episode of ATPD completed the study with a diagnostic stability rate as high as 55.9% (n = 38) at the end of the follow-up period. Multivariate analysis revealed that diagnostic stability was independently significantly associated with the baseline presence of motility disturbances (OR = 6.86, 95% CI = 1.10-42.62; P = 0.039), the absence of hallucinations (OR = 5.75, 95% CI = 1.51-21.98; P = 0.010), and the absence of schizophrenic features (OR = 7.13, 95% CI = 1.38-36.90; P = 0.019).

CONCLUSION

A symptom checklist assessing these psychopathological features would enable early identification of those subjects whose initial ATPD diagnosis will remain stable over time.

Acute and Transient Psychotic Disorders: Newer Understanding

PURPOSE OF REVIEW

We review the ongoing research in the area of acute and transient psychotic disorders (ATPDs) with regard to their nosology, epidemiology, clinical description, genetics, and neurobiology, examining evidence for distinctiveness or otherwise of ATPDs. We further highlight the lacuna in research in ATPDs.

RECENT FINDINGS

Studies on ATPDs as defined in the ICD 10 have been reported from different parts of the world, more so from the developing countries. There is consistent evidence that there exist a group of ATPDs that occur more commonly among females, are often precipitated by stressful life events or exposure to physiological stresses like fever, child birth, are associated with well-adjusted premorbid personality, and show complete recovery in a short period. Although in some cases of ATPDs, there is symptomatic overlap with schizophrenic symptoms in the acute phase, they follow a completely different course and outcome, exhibit genetic distinctiveness, and do not share genetic relationship with schizophrenias or bipolar affective disorder (BPAD). Comparative studies on neurophysiology and neuroimaging in ATPDs and schizophrenias have demonstrated evidence of hyper arousal and hyper metabolism in ATPDs vs hypo arousal and hypo metabolism as noted in the P300 response and on FDG PET studies, respectively. Immune markers such as IL-6, TNF-alpha, and TGF-beta show higher levels in ATPDs as compared to healthy controls. Findings on the neurobiological mechanisms underlying ATPDs, so far, point towards significant differences from those in schizophrenia or BPAD. Although the studies are few and far between, nevertheless, these point towards the possibility of ATPDs as a distinct entity and underscore the need for pursuing alternate hypothesis such as neuro inflammatory or metabolic. Research on ATPDs is limited due to many reasons including lack of harmony between the ICD and DSM diagnostic systems and clinician biases. Available research data supports the validity of ATPDs as a distinct clinical entity. There is also evidence that ATPDs are different from schizophrenias or BPAD on genetic, neuroimaging, neurophysiological, and immunological markers and require further studies.

Meta-analysis of natural, unnatural and cause-specific mortality rates following discharge from in-patient psychiatric facilities

BACKGROUND

People discharged from in-patient psychiatric facilities have highly elevated rates of suicide, and there is increasing concern about natural mortality among the seriously mentally ill.

METHOD

A meta-analysis of English-language, peer-reviewed longitudinal studies of mortality among patients discharged from in-patient psychiatric facilities was conducted using papers published in MEDLINE, PsycINFO or EMBASE (from 1 January 1960 to 1 April 2018) located using the terms ((suicid*).ti AND (hospital OR discharg* OR inpatient OR in-patient OR admit*)).ab and ((mortality OR outcome* OR death*) AND (psych* OR mental*)).ti AND (admit* OR admis* OR hospital* OR inpatient* OR in-patient* OR discharg*).ab. Pooled mortality rates for aggregated natural and unnatural causes, and the specific causes of suicide, accident, homicide, vascular, neoplastic, respiratory, gastrointestinal, infectious and metabolic death were calculated using a random-effects meta-analytic model. Between-study heterogeneity was investigated using subgroup analysis and metaregression.

RESULTS

The pooled natural death rate of 1128 per 100 000 person-years exceeded the pooled unnatural deaths of 479 per 100 000 person-year among studies with varying periods of follow-up. Natural deaths significantly exceeded unnatural deaths among studies with a mean follow-up of longer than 2 years, and vascular deaths exceeded suicide deaths among studies with mean period of follow-up of 5 years or longer.

CONCLUSION

Suicide may be the largest single cause of death in the short term after discharge from in-patient psychiatric facilities but vascular disease is the major cause of mortality in the medium- and long-term.

Enzymatic activity of palmitoyl-protein thioesterase-1 in serum from schizophrenia significantly associates with schizophrenia diagnosis scales

Genome-wide association studies have confirmed that schizophrenia is an inheritable multiple-gene mental disorder. Longitudinal studies about depression, first episode psychosis (FEP) and acute psychotic relapse have mostly searched for brain imaging biomarkers and inflammatory markers from the blood. However, to the best of our knowledge, the association between enzymatic activities with diagnosis or prediction of treatment response in people with schizophrenia has barely been validated. Under the Longitudinal Study of National Mental Health Work Plan (2015-2020), we have studied a subsample of approximately 36 individuals from the cohort with data on palmitoyl-protein thioesterase-1 enzymatic activity from FEP and performed a bivariate correlation analysis with psychiatric assessment scores. After adjusting for sex, age, body mass index (BMI) and total serum protein, our data demonstrated that PPT1 enzymatic activity is significantly associated with schizophrenia and its Positive and Negative Syndrome Scale (PANSS) scores. This longitudinal study compared the PPT1 enzymatic activity in FEP schizophrenia patients and healthy volunteers, and the former exhibited a significant 1.5-fold increase in PPT1 enzymatic levels (1.79 mmol/L/h/mL, and 1.18 mmol/L/h/mL; P < 0.05; 95% CI, 2.3-2.9 and 1.4-1.8). The higher PPT1 enzymatic levels in FEP schizophrenia patients were positively associated with larger PANSS scaling scores (r = 0.32, P = 0.0079 for positive scaling; r = 0.41, P = 0.0006 for negative scaling; r = 0.45, P = 0.0001 for general scaling; and r = 0.34, P = 0.0048 for PNASS-S scaling). Higher enzymatic PPT1 in FEP schizophrenia patients is significantly associated with increased PANSS scaling values, indicating more serious rates of developing psychosis. Enzymatic activity of PPT1 may provide an important new view for schizophrenia disorders.

Risk and associated factors for a future schizophrenia diagnosis after an index diagnosis of unspecified psychotic disorder: A population-based study

A significant minority of unspecified psychosis presentations progress to schizophrenia. Clinical risk factors can inform targeted referral to specialized treatment programs, but few population studies have examined this. In this study, we used health administrative data for a population-based cohort from Manitoba, Canada to characterize the risk and identify vulnerable subgroups for a future diagnosis of schizophrenia after a diagnosis of unspecified psychotic disorder. Individuals aged 13-60 years with an inpatient or outpatient diagnosis of unspecified psychotic disorder between April 1, 2007 and March 31, 2012, and without any prior diagnosis of schizophrenia or related disorder, were identified (N = 3, 289). The primary outcome was a diagnosis of schizophrenia recorded after the index diagnosis of unspecified psychotic disorder and before March 31, 2015. Adjusted hazard ratios were computed controlling for age, sex, urbanicity, income, prior diagnosis of unspecified psychotic disorder, provider making the diagnosis, prior 12-month psychiatric hospitalization, and prior 12-month diagnoses of mood, anxiety, substance use, or personality disorders, and substance-induced psychosis. A classification tree identified vulnerable subgroups. The cumulative risk of a future diagnosis of schizophrenia was 26% during the follow-up period (mean 4.5 years), with a mean time to diagnosis of 2.0 years. The most vulnerable subgroup was diagnosed by a psychiatrist, younger than 27 years, without a mood or anxiety disorder, male, and residing in a low-income neighborhood; the rate of a subsequent schizophrenia diagnosis was 61.2%. These results support that identification of specific sociodemographic and clinical factors can help clinicians counsel and intervene with those at highest risk.

Acute stress and substance use as predictors of suicidal behaviour in acute and transient psychotic disorders

Several authors have reported high rates of suicidal behaviour in acute and transient psychotic disorders (ATPD). However, the literature in this area remains scarce. We wanted to find out whether there are predictors of suicidal behaviour in ATPD. Of 1032 psychosis admissions examined over a five-year period, ATPD was confirmed in 39 patients according to the International Classification of Diseases (ICD-10) diagnostic criteria. These patients were classified as suicidal behaviour (20.5%) or non-risk (79.5%) using a structured interview to assess suicidal risk. The following variables were analysed: previous history of suicide attempt or deliberate self-harm, history of depressive episodes, previous substance use history, education, ATPD subtype (polymorphic vs. non-polymorphic), type of onset (abrupt vs. acute), and presence of associated acute stress. Multivariate analysis revealed that acute stress and substance use are significantly associated with suicidal behaviour in ATPDs. To our knowledge, this is the first study identifying independent risk factors that could predict suicidal behaviour in individuals with ATPD.

Diagnostic validity of ICD-10 acute and transient psychotic disorders and DSM-5 brief psychotic disorder

BACKGROUND

Short-lived psychotic disorders are currently classified under "acute and transient psychotic disorders" (ATPDs) in ICD-10, and "brief psychotic disorder" (BPD) in DSM-5. This study's aim is to review the literature and address the validity of ATPDs and BPD.

METHOD

Papers published between January 1993 and December 2016 were identified through searches in Web of Science. Reference lists in the located papers provided further sources.

RESULTS

A total of 295 articles were found and 100 were included in the review. There were only a few studies about the epidemiology, vulnerability factors, neurobiological correlates and treatment of these disorders, particularly little interest seems to exist in BPD. The available evidence suggests that short-lived psychotic disorders are rare conditions and more often affect women in early to middle adulthood. They also are neither associated with premorbid dysfunctions nor characteristic family predisposition, while there seems to be greater evidence of environmental factors particularly in developing countries and migrant populations. Follow-up studies report a favourable clinical and functional outcome, but case identification has proved difficult owing to high rates of transition mainly either to schizophrenia and related disorders or, to a lesser extent, affective disorders over the short- and longer-terms.

CONCLUSIONS

Although the lack of neurobiological findings and little predictive power argue against the validity of the above diagnostic categories, it is important that they are kept apart from longer-lasting psychotic disorders both for clinical practice and research. Close overlap between ATPDs and BPD could enhance the understanding of these conditions.

Diagnostic Stability of Acute and Transient Psychotic Disorders in Developing Country Settings: An Overview

Acute and transient psychotic disorders (ATPD), introduced in the International Classification of Diseases (ICD-10) diagnostic system in 1992, are not receiving much attention in developing countries. Therefore, the main objective of this article is to review the literature related to the diagnostic stability of ATPD in developing countries. A PubMed search was conducted to review the studies concerned with this issue in the context of developing countries, as diagnostic stability is more of a direct test of validity of psychiatric diagnoses. Four publications were found. According to the literature search, the stability percentage of the ICD-10 ATPD diagnosis is 63-100%. The diagnostic shift is more commonly either towards bipolar disorder or schizophrenia, if any. Shorter duration of illness (<1 month) and abrupt onset (<48 hours) predict a stable diagnosis of ATPD. Based on available evidence, the diagnosis of ATPD appears to be relatively stable in developing countries. However, it is difficult to make a definitive conclusion, as there is a substantial lack of literature in developing country settings.

A prospective follow-up study of first-episode acute transient psychotic disorder in Latvia

BACKGROUND

Acute and transient psychotic disorder (ATPD) has been described as an acute psychosis with brief onset and polymorphous symptomatology (WHO, 1993). The study of ATPD is growing increasingly relevant as scientists start an active discussion of the possibility of changing the ATPD classification in the next International Classification of Diseases (ICD-11). The aims of this study were to describe the clinical features of the index episode of ATPD in patients in Latvia, to analyse the stability and longitudinal changes of the diagnosis, to explore potential correlations between the sociodemographic and disease characteristics and to describe stressful life events before the first ATPD episode.

METHODS

A prospective follow-up study of all first-time admitted patients from the Riga Centre of Psychiatry and Addiction Disorders who fulfilled the ICD-10 criteria for ATPD (WHO, 1993) during the 15-month period from 9 January 2010 to 30 March 2011 and followed up until 31 October 2012. Stressful life events, demographics and clinical features during the index episode were assessed.

RESULTS

One hundred two patients were admitted with first-episode ATPD. The majority were females (60.7%). Over an average 26.5-month follow-up period, 59.8% of the patients were not readmitted. The overall stability rate of ATPD diagnosis in our sample was 67.4% (p = 0.0001). In the subgroup of patients who were readmitted, 70.7% had their diagnosis converted to schizophrenia in subsequent visits. Stressful life events before the first episode were found in 49.0% of first-episode ATPD patients. Thought disorder was found to be the strongest statistically significant predictor of ATPD diagnosis conversation to schizophrenia (odds ratio 4.3), with high Wald's criterion (9.435) in binary logistic regression.

CONCLUSIONS

ATPD is prevalent in Latvia, with rather high overall stability rate. Combining these data from first-episode ATPD patients in Latvia with data from other countries may help predict the development of the disease and provide a basis for potential changes to ICD-11.

Epidemiology, course and outcome of acute polymorphic psychotic disorder: implications for ICD-11

BACKGROUND

The proposed revision of the ICD-10 category of 'acute and transient psychotic disorders' (ATPDs), subsuming polymorphic, schizophrenic or predominantly delusional syndromes, would restrict their classification to acute polymorphic psychotic disorder, reminiscent of the clinical concepts of bouffée délirante and cycloid psychosis.

SAMPLING AND METHODS

We selected all subjects aged 15-64 years (n = 5,426) who were listed in the Danish Psychiatric Central Register with a first-admission diagnosis of ATPDs in 1995-2008 and estimated incidence rates, course and outcome up to 2010.

RESULTS

Although about half of ATPD patients tended to experience transition to another category over a mean follow-up period of 9.3 years, acute polymorphic psychotic disorder fared better in terms of cases with a single episode of psychosis and temporal stability than the subtypes featuring schizophrenic or predominantly delusional symptoms. Acute polymorphic psychotic disorder was more common in females, while cases with acute schizophrenic features predominated in younger males and evolved more often into schizophrenia and related disorders.

CONCLUSIONS

These findings suggest that acute polymorphic psychotic disorder exhibits distinctive features and challenge the current approach to the classification of ATPDs.

Variations in incidence and age of onset of acute and transient psychotic disorders

PURPOSE

To determine incidence and age of onset of the ICD-10 category of 'acute and transient psychotic disorders' (ATPDs) characterised by subtypes with polymorphic, schizophrenic and predominantly delusional symptoms, pointing out differences from schizophrenia (SZ) and bipolar affective disorder (BD).

METHODS

We identified all subjects aged 15-64 years who were listed for the first time in the Danish Psychiatric Register with a diagnosis of ATPDs (n = 3,350), SZ (n = 4,576) and BD (n = 3,200) in 1995-2008. Incidence rates and rate ratios (IRR; 95 % confidence interval) by gender and age were calculated.

RESULTS

The incidence of ATPDs was 6.7 per 100,000 person-years, similarly high for both genders (IRR 1.0; 0.9-1.1). Among the ATPD subtypes, polymorphic psychotic disorder was more common in females (IRR 1.4; 1.2-1.6) as opposed to those featuring schizophrenic symptoms, which tended to occur in younger males (IRR 1.4; 1.2-1.7). No significant gender difference was found for acute predominantly delusional disorder (IRR 1.0; 0.9-1.2), which had a later onset than any ATPD subtypes. SZ had an incidence twice as high in males (IRR 2.0; 1.9-2.2), and an earlier age of onset than ATPDs. A different pattern was observed for BD in terms of a slightly greater incidence in females (IRR 1.1; 1.0-1.1), and a later age of onset than both ATPDs and SZ.

CONCLUSION

These findings are likely to reflect the heterogeneity of the clinical features encompassed by ATPDs, and contribute to building a case for their revision in ICD-11.

Excess mortality of acute and transient psychotic disorders: comparison with bipolar affective disorder and schizophrenia

OBJECTIVE

To investigate mortality and causes of death of short-lived psychotic disorders, by carrying out a comparison with bipolar disorder and schizophrenia.

METHOD

Record linkage study to the official register of causes of death of all cases aged 15-64 years who were listed for the first time in the Danish Psychiatric Register between 1995 and 2008 with an ICD-10 diagnosis of 'acute and transient psychotic disorders' (ATPDs; n = 4157), bipolar disorder (n = 3200) and schizophrenia (n = 4576).

RESULTS

A total of 232 patients (5.6%) with ATPDs, 172 (5.4%) with bipolar disorder and 233 (5.1%) with schizophrenia had died over a mean follow-up period of 6.6 years. The standardized mortality ratio for all causes, natural causes and unnatural causes was significantly high for the three conditions. Mortality of ATPDs was greater in men, with about two-thirds of all deaths resulting from natural causes mainly cardiovascular, digestive, neoplastic and respiratory diseases. Suicide was the major cause of premature death in patients with ATPDs.

CONCLUSION

These findings suggest that ATPDs are associated with an increased mortality from both natural causes and suicide.

US regional differences in death rates from depression

BACKGROUND

Studies in a few countries (including the US) have reported that mortality rates in the population from psychiatric disorders are much higher when they are based on all causes of death ("multiple causes" or "mentions") coded on death certificates versus only the underlying cause. Studies appear to be lacking on geographic variation within the US in mortality rates from psychiatric disorders based on multiple causes of death.

METHOD

The present study examined the US age-standardized rate (ASR) for death with depression using multiple causes versus underlying cause alone in each of the Census Bureau's four regions and nine divisions. ASRs for schizophrenia were also examined for comparison.

RESULTS

For the entire US, the ratio of the ASR based on multiple causes to the ASR based on underlying cause was 20.9 for depression and 9.2 for schizophrenia; in analyses by region and division, these ratios showed limited variation. The most consistent finding for both depression and schizophrenia was that ASRs, whether based on multiple causes or only on underlying cause, were highest in the Midwest region (especially the East North Central division) and lowest in the South (and in each of its three divisions). For ASRs (using multiple causes of death) from depression, these regional differences were evident within each of several levels of urbanization. For deaths with depression coded as other than the underlying cause, ASRs for each of the three most common underlying causes (cardiovascular diseases, intentional injuries, and neoplasms) were highest in the Midwest and lowest in the South.

CONCLUSION

Studies are needed to determine if these regional differences in mortality from depression are due to regional differences in: certifier practices (i.e., in assigning causes of death among persons with psychiatric conditions); the prevalence (among persons with psychiatric disorders) of lifestyle-related factors (e.g., tobacco use and obesity) that mediate mortality risks; and/or in unmet need for psychiatric treatment and medical care for other chronic diseases in persons with psychiatric conditions. Similar studies are needed of regional variation within other countries.

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.