Interrater reliability of schizoaffective disorder compared with schizophrenia, bipolar disorder, and unipolar depression - A systematic review and meta-analysis

In-Hospital Use of Long-Acting Injectable Antipsychotics and Readmission Risk in Patients With First-Admission Schizophrenia in Taiwan

Importance

Long-acting injectable antipsychotics (LAIs) can help decrease the rate of nonadherence to medications in patients with schizophrenia, but these drugs are underutilized in clinical practice, especially in Asian countries. One strategy for the early prescription of LAIs is to administer the drugs during patients' first admission, when they have more time to absorb medication-related knowledge.

Objective

To estimate the prevalence of and risk factors for in-hospital use of LAIs among first-admission patients with schizophrenia in Taiwan and to examine the association of early discontinuation with readmission risk among patients receiving LAIs.

Design, Setting, and Participants

This cohort study included data from a claims database for patients with a first admission for schizophrenia at psychiatric wards in Taiwan from 2004 to 2017. Eligible patients were diagnosed with schizophrenia or schizoaffective disorder at discharge and aged between 15 and 64 years. Data analysis was performed from April to September 2022.

Exposure

In-hospital use of LAIs with or without early discontinuation.

Main Outcome and Measures

Readmission for any psychotic disorder following discharge from first admission, with risk estimated via multivariable survival regression analysis, including the Cox proportional hazards (CPH) model and accelerated failure time (AFT) model.

Results

Of the 56 211 patients with a first admission for schizophrenia (mean [SD] age, 38.1 [12.1] years; 29 387 men [52.3%]), 46 875 (83.4%) did not receive any LAIs during admission, 5665 (10.1%) received LAIs with early discontinuation, and 3671 (6.5%) received LAIs without early discontinuation. The prevalence of receiving LAIs increased by 4%, from 15.3% (3863 of 25 251 patients) to 19.3% (3013 of 15 608 patients) between 2004-2008 and 2013-2017. After controlling for sex, year, prior antipsychotic use, age at first admission, and length of stay, the CPH regression analysis revealed that the readmission risk increased among patients receiving LAIs with early discontinuation (adjusted hazard ratio [aHR], 1.25; 95% CI, 1.21-1.30) but decreased among patients receiving LAIs without early discontinuation (aHR, 0.88; 95% CI, 0.84-0.92) compared with patients not receiving LAIs. Results remained similar for the AFT model.

Conclusions and Relevance

The incidence of in-hospital use of LAIs among patients with a first admission for schizophrenia has remained low. In this study, early discontinuation of LAIs was associated with readmission risk-specifically, early discontinuation with a higher risk while the lack of early discontinuation with a lower risk compared with treatment with oral antipsychotics alone-which suggests our results have implications for improving the efficacy of LAI administration among patients with a first admission for schizophrenia.

The future of diagnosis in clinical neurosciences: Comparing multiple sclerosis and schizophrenia

The ongoing developments of psychiatric classification systems have largely improved reliability of diagnosis, including that of schizophrenia. However, with an unknown pathophysiology and lacking biomarkers, its validity still remains low, requiring further advancements. Research has helped establish multiple sclerosis (MS) as the central nervous system (CNS) disorder with an established pathophysiology, defined biomarkers and therefore good validity and significantly improved treatment options. Before proposing next steps in research that aim to improve the diagnostic process of schizophrenia, it is imperative to recognize its clinical heterogeneity. Indeed, individuals with schizophrenia show high interindividual variability in terms of symptomatic manifestation, response to treatment, course of illness and functional outcomes. There is also a multiplicity of risk factors that contribute to the development of schizophrenia. Moreover, accumulating evidence indicates that several dimensions of psychopathology and risk factors cross current diagnostic categorizations. Schizophrenia shares a number of similarities with MS, which is a demyelinating disease of the CNS. These similarities appear in the context of age of onset, geographical distribution, involvement of immune-inflammatory processes, neurocognitive impairment and various trajectories of illness course. This article provides a critical appraisal of diagnostic process in schizophrenia, taking into consideration advancements that have been made in the diagnosis and management of MS. Based on the comparison between the two disorders, key directions for studies that aim to improve diagnostic process in schizophrenia are formulated. All of them converge on the necessity to deconstruct the psychosis spectrum and adopt dimensional approaches with deep phenotyping to refine current diagnostic boundaries.

Schizophrenia or schizoaffective disorder? A 50-year assessment of diagnostic stability based on a national case registry

BACKGROUND

Schizoaffective disorder (SAD) remains a controversial diagnosis in terms of necessity and reliability.

OBJECTIVES

We assessed diagnostic patterns of SAD and schizophrenia (SZ) among hospitalized psychiatric patients over a fifty-year period.

METHOD

Data from the Israeli National Psychiatric Registry on 16,341 adults diagnosed with SZ or SAD, hospitalized at least twice in 1963-2017, were analyzed. Stability between most-frequent, first and last diagnosis, and diagnostic-constancy (the same diagnosis in >75 % of a person's hospitalizations) were calculated. Three groups were compared: People with both SAD and SZ diagnoses over the years (SZ-SAD), and people with only one of these diagnoses (SZ-only; SAD-only). The incidence of SAD and SZ before and after DSM-5 publication was compared.

RESULTS

Reliability between last and first diagnosis was 60 % for SAD and 94 % for SZ. Agreement between first and most-frequent diagnosis was 86 % for SAD and 92 % for SZ. Diagnostic shifts differ between persons with SAD and with SZ. Diagnostic-constancy was observed for 50 % of SAD-only patients. In the SZ-SAD group, 9 % had a constant SAD diagnosis. Compared to the other groups, the SZ-SAD group exhibited a higher substance use prevalence, younger age at first-hospitalization, and more hospitalizations/person (p < 0.0001). The incidence of a first-hospitalization SAD diagnosis increased by 2.2 % in the 4-years after vs. prior to DSM-5.

CONCLUSIONS

A SAD diagnosis is less stable than SZ. The incidence of a SAD diagnosis increased after DSM-5, despite stricter diagnostic criteria. The SZ-SAD group exhibited the poorest outcomes. SAD may evolve over time necessitating periodic re-evaluation.

The impact of antipsychotic adherence on acute care utilization

BACKGROUND

Non-adherence to psychotropic medications is common in schizophrenia and bipolar disorders (BDs) leading to adverse outcomes. We examined patterns of antipsychotic use in schizophrenia and BD and their impact on subsequent acute care utilization.

METHODS

We used electronic health record (EHR) data of 577 individuals with schizophrenia, 795 with BD, and 618 using antipsychotics without a diagnosis of either illness at two large health systems. We structured three antipsychotics exposure variables: the proportion of days covered (PDC) to measure adherence; medication switch as a new antipsychotic prescription that was different than the initial antipsychotic; and medication stoppage as the lack of an antipsychotic order or fill data in the EHR after the date when the previous supply would have been depleted. Outcome measures included the frequency of inpatient and emergency department (ED) visits up to 12 months after treatment initiation.

RESULTS

Approximately half of the study population were adherent to their antipsychotic medication (a PDC ≥ 0.80): 53.6% of those with schizophrenia, 52.4% of those with BD, and 50.3% of those without either diagnosis. Among schizophrenia patients, 22.5% switched medications and 15.1% stopped therapy. Switching and stopping occurred in 15.8% and 15.1% of BD patients and 7.4% and 20.1% of those without either diagnosis, respectively. Across the three cohorts, non-adherence, switching, and stopping therapy were all associated with increased acute care utilization, even after adjusting for baseline demographics, health insurance, past acute care utilization, and comorbidity.

CONCLUSION

Non-continuous antipsychotic use is common and associated with high acute care utilization.

Deep learning model using retinal vascular images for classifying schizophrenia

Contemporary psychiatric diagnosis still relies on the subjective symptom report of the patient during a clinical interview by a psychiatrist. Given the significant variability in personal reporting and differences in the skill set of psychiatrists, it is desirable to have objective diagnostic markers that could help clinicians differentiate patients from healthy individuals. A few recent studies have reported retinal vascular abnormalities in patients with schizophrenia (SCZ) using retinal fundus images. The goal of this study was to use a trained convolution neural network (CNN) deep learning algorithm to detect SCZ using retinal fundus images. A total of 327 subjects [139 patients with Schizophrenia (SCZ) and 188 Healthy volunteers (HV)] were recruited, and retinal images were acquired using a fundus camera. The images were preprocessed and fed to a convolution neural network for the classification. The model performance was evaluated using the area under the receiver operating characteristic curve (AUC). The CNN achieved an accuracy of 95% for classifying SCZ and HV with an AUC of 0.98. Findings from the current study suggest the potential utility of deep learning to classify patients with SCZ and assist clinicians in clinical settings. Future studies need to examine the utility of the deep learning model with retinal vascular images as biomarkers in schizophrenia with larger sample sizes.

Characterization of affective lability across subgroups of psychosis spectrum disorders

BACKGROUND

Affective lability is elevated and associated with increased clinical burden in psychosis spectrum disorders. The extent to which the level, structure and dispersion of affective lability varies between the specific disorders included in the psychosis spectrum is however unclear. To have potential value as a treatment target, further characterization of affective lability in these populations is necessary. The main aim of our study was to investigate differences in the architecture of affective lability in different psychosis spectrum disorders, and if putative differences remained when we controlled for current symptom status.

METHODS

Affective lability was measured with The Affective Lability Scale Short Form (ALS-SF) in participants with schizophrenia (SZ, n = 76), bipolar I disorder (BD-I, n = 105), bipolar II disorder (BD-II, n = 68) and a mixed psychosis-affective group (MP, n = 48). Multiple analyses of covariance were conducted to compare the ALS-SF total and subdimension scores of the diagnostic groups, correcting for current psychotic, affective and anxiety symptoms, substance use and sex. Double generalized linear models were performed to compare the dispersion of affective lability in the different groups.

RESULTS

Overall group differences in affective lability remained significant after adjusting for covariates (p = .001). BD-II had higher affective lability compared to SZ and BD-I (p = .004), with no significant differences between SZ and BD-I. There were no significant differences in the contributions of ALS-SF dimensions to the total affective lability or in dispersion of affective lability between the groups.

CONCLUSIONS

This study provides the construct of affective lability in psychosis spectrum disorders with more granular details that may have implications for research and clinical care. It demonstrates that despite overlap in core symptom profiles, BD-I is more similar to SZ than it is to BD-II concerning affective lability and the BD groups should consequently be studied apart. Further, affective lability appears to be characterized by fluctuations between depressive- and other affective states across different psychosis spectrum disorders, indicating that affective lability may be related to internalizing problems in these disorders. Finally, although the level varies between groups, affective lability is evenly spread and not driven by extremes across psychosis spectrum disorders and should be assessed irrespective of diagnosis.

Clozapine in patients with schizoaffective disorder: A systematic review

Schizoaffective disorder is defined by the appearance of positive psychotic symptomatology as well as affective features, even when it is considered a controversial nosologic entity, proving difficult to accord on its definition or diagnostic criteria. Due to these conceptual differences, it has been a challenge to study effective therapeutic measures and, consequently, the availability of data in the current literature, resulting in the extrapolation of clinical guidelines and recommendations initially established for patients with schizophrenia or bipolar disorder. The current study aimed to systematically search and summarize the published evidence to date about the use of clozapine in patients with schizoaffective disorder. Seven studies were identified, that are heterogeneous on their designs and methodology, including samples of patients mixed with bipolar or schizophrenic disorders. The evidence was summarized both in a table and a narrative fashion, suggesting that clozapine may be an effective treatment for both psychotic and affective symptoms, indistinctively of an acute or maintenance phase.

Interrater agreement in dementia diagnosis: A systematic review and meta-analysis

OBJECTIVES

Dementia remains a clinical diagnosis with a degree of subjective assessment and potential for interrater disagreement. We described interrater agreement of clinical dementia diagnosis for various diagnostic criteria.

METHODS

We conducted a PROSPERO-registered (CRD42020168245) systematic review and meta-analysis. We searched multiple cross-disciplinary databases from inception until April 2020 for relevant papers, extracted data and described study quality in duplicate. Study quality was assessed using the Guidelines for Reporting Reliability and Agreement Studies. We used random-effects models to obtain summary estimates of interrater agreement using kappa and, where possible, Gwet's AC1/2 coefficients.

RESULTS

We found 7577 titles and 22 eligible studies. Meta-analysis was possible for all-cause dementia using the Diagnostic and Statistical Manual of Mental Disorders third edition revised (DSM-III-R) criteria (kappa = 0.66, 95% CI = [0.53,0.78]), Alzheimer's disease using the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's disease and Related Disorders Association (NINCDS-ADRDA) criteria (kappa = 0.71, 95% CI = [0.65,0.77] for presence/absence and AC2 = 0.61, 95% CI = [0.53,0.70] when distinguishing probable/possible cases), and vascular dementia using the International Classification of Diseases version 10 (ICD-10) criteria kappa = 0.79 (95% CI = [0.70,0.87]). Data was more limited for other criteria and dementia types. AC1/2 coefficients generally indicated higher agreement. One study was rated as high quality.

CONCLUSIONS

Diagnostic criteria for clinical dementia may have good but imperfect agreement. This has important implications for clinical practice and research studies, which frequently assume these criteria are perfect tests, such as diagnostic test accuracy studies frequently conducted for biomarkers and neuropsychological tests, and for trials where incident dementia is the outcome.

The bumpy road to achieve reliability of clinical profile characteristics in psychosis and related disorders

OBJECTIVES

Profile characteristics are factors that are relevant for diagnosis, prognosis or treatment. The present study aims to develop a set of clinically relevant profile characteristics. Moreover, our goal is to determine the inter-rater reliability (IRR) of the selected profile characteristics.

METHODS

Potential profile characteristics were determined by literature review. Assessment of IRR was done by comparing scores on profile characteristics determined by two researchers. We conducted three subsequent studies: (1) assessment of pre-training IRR, (2) IRR following implementation of an instruction manual, (3) IRR after optimizing scoring methods. IRR was measured with the Intraclass Correlation Coefficient (ICC).

RESULTS

IRR scores of profile characteristic Illegal activities were high across the three studies (ICC ≥ 0.75). Following training procedures in study 2 and 3, reliability estimates remained low to moderate (ICC < 0.75) for the profile characteristics Support of relatives, Aggression recent and lifetime, substance use and insight recent. IRR scores of the other eight profile characteristics varied from low, moderate to high across studies.

CONCLUSION

IRR scores of profile characteristics were highly variable, and mostly inadequate in all three studies. Consequently, further research should focus on specification of severity scores of profile characteristics, optimizing scoring methods and re-evaluation of IRR.

Non-psychiatric hospitalization length-of-stay for patients with psychotic disorders: A mixed methods study

OBJECTIVE

Patients with psychotic disorders experience higher rates of chronic and acute non-psychotic diseases and have frequent non-psychiatric hospitalizations which result in both longer and more varied length-of-stay (LoS) than other patients. This study seeks to use a patient-centered perspective to examine LoS.

METHODS

This article reports Phase Two of a mixed methods, exploratory sequential study on non-psychiatric hospitalizations for individuals with psychotic disorders. Patients' experiences were used to guide a quantitative analysis of LoS using a general linear model.

RESULTS

Medical comorbidities were the patient characteristics which had the largest effect on LoS. Certain processes of care highlighted by patients from Phase One were also associated with longer LoS, including: physical restraints (105%), psychiatric consults (20%) and continuous observation (133%). Only recent in-system outpatient appointments were associated with shorter LoS. Data integration highlighted that factors which were important to patients such as partner support, were not always quantitatively significant, while others like medical comorbidities and use of physical restraints were points of congruence.

CONCLUSIONS

Medical comorbidities were highly associated with LoS but processes relating to longer LoS are those that are used to manage symptoms of acute psychosis. Clinicians should develop policies and procedures that address psychosis symptoms effectively during non-psychiatric hospitalizations. Further research is needed to understand which patients with psychotic disorders are at highest risk of extended length-of-stay.

Clozapine in patients with schizoaffective disorder: A systematic review

Schizoaffective disorder is defined by the appearance of positive psychotic symptomatology as well as affective features, even when it is considered a controversial nosologic entity, proving difficult to accord on its definition or diagnostic criteria. Due to these conceptual differences, it has been a challenge to study effective therapeutic measures and, consequently, the availability of data in the current literature, resulting in the extrapolation of clinical guidelines and recommendations initially established for patients with schizophrenia or bipolar disorder. The current study aimed to systematically search and summarize the published evidence to date about the use of clozapine in patients with schizoaffective disorder. Seven studies were identified, that are heterogeneous on their designs and methodology, including samples of patients mixed with bipolar or schizophrenic disorders. The evidence was summarized both in a table and a narrative fashion, suggesting that clozapine may be an effective treatment for both psychotic and affective symptoms, indistinctively of an acute or maintenance phase.

Diagnostic Stability in Bipolar Disorder: A Narrative Review

LEARNING OBJECTIVES

After participating in this activity, learners should be better able to:• Evaluate diagnostic stability in bipolar disorder• Analyze the factors contributing to diagnostic stability OBJECTIVE: Diagnostic stability is the degree to which a diagnosis remains unchanged during follow-up. It is an important measure of predictive validity in bipolar disorder (BD). In this study, we review the literature concerning diagnostic stability in BD, analyze the factors contributing to diagnostic stability, and describe the implications of diagnostic boundaries and diagnostic delay.

METHODS

A comprehensive literature search of MEDLINE and EMBASE databases was conducted, including all studies published from 1980 to 2016, to evaluate the diagnostic stability of BD. Thirty-seven articles were included: 6 focusing mainly on BD, 18 on psychotic disorders, 10 on depression, and 3 on diagnostic stability in psychiatric disorders in general. Data analysis was performed in standardized fashion using a predefined form.

RESULTS

Despite a high variability of the methodological approaches taken, an acceptable degree of diagnostic stability was found. The most common criteria for evaluating diagnostic stability were prospective consistency and retrospective consistency. The mean prospective and retrospective consistencies were 77.4% and 67.6%, respectively. A large majority of studies were performed in Europe or in North America (67.5%), compared to 21.6% in Asia and only 10.8% in Africa, Oceania, and South America. Extreme ages, female gender, psychotic symptoms, changes to treatment, substance abuse, and family history of affective disorder have been related to diagnostic instability.

CONCLUSIONS

Several factors appear to have a negative impact on the diagnostic stability, but the evidence is insufficient to draw any robust conclusions. Nevertheless, despite variable prospective and retrospective consistencies, the overall diagnostic stability is good. Standardized methods need to be used to obtain more accurate assessments of stability.

Staging and profiling for schizophrenia spectrum disorders: Inter-rater reliability after a short training course

OBJECTIVE

Clinical staging and profiling have been proposed as a new approach in order to refine the diagnostic assessment of schizophrenia spectrum disorders. However, only limited evidence is available for the inter-rater reliability of the clinical staging and profiling model. The aim of the present study was therefore to determine the inter-rater reliability of the clinical staging and profiling model for schizophrenia spectrum disorders, and to investigate whether a short course can improve inter-rater reliability.

METHODS

Consecutively recruited inpatients with schizophrenia spectrum disorders were included between January 2015 and January 2016 (study 1), and between March 2018 and October 2018 (study 2). By contrast with the assessors in study 1, all the assessors in study 2 were trained in clinical staging and profiling. We used the clinical staging model proposed by McGorry and identified profile characteristics. Inter-rater reliability was measured using the Intraclass Correlation Coefficient (ICC).

RESULTS

The ICC score for clinical staging in study 1 was moderate (0.578). It improved considerably in study 2 (0.757). In general, the ICC scores for the profile characteristics in studies 1 and 2 ranged from poor to sufficient (0.123-0.781).

CONCLUSION

This study demonstrated that inter-rater reliability in clinical staging was sufficient after training. However, inter-rater reliability for clinical profile characteristics was highly variable. The general implementation of the clinical staging model for schizophrenia spectrum disorders is therefore feasible but clinical profile characteristics should be used with caution.

Steeper aging-related declines in cognitive control processes among adults with bipolar disorders

BACKGROUND

Little is known about the specificity of executive functioning (EF) decline in older adults with bipolar disorders (OABD), or the impact of bipolar disorders (BD) on the timing and slope of age-related declines in EF processes implicated in both BD etiology and normative aging-cognitive control (CC). This cross-sectional study investigated age-related CC decline in BD.

METHODS

Participants were 43 adults with BD (M age = 61.5, SD = 15.8; 86% male) and 45 Controls (M age = 65.2, SD = 12.2; 98% male). Two-way ANOVAs examined the effects of median-age-split and diagnostic groups on cognitive processes with established BD deficits-CC processes (mental flexibility and response inhibition), verbal learning, and verbal fluency.

RESULTS

The median-split-age-by-diagnostic-group interaction was significant for mental flexibility; OABD performed significantly worse than younger adults with BD and younger and older Controls. Exploratory multivariate adaptive regression spline characterized non-linear nature of aging-slope changes in mental flexibility for each diagnostic group, yielding an inflection point at older age and steeper subsequent decline in OABD versus Controls.

LIMITATIONS

This study is limited by a small sample (particularly for select neuropsychological measures) of mostly Caucasian men and BD diagnoses based on clinical interview and medical records review.

CONCLUSIONS

Compared to healthy older adults, OABD showed steeper age-related decline in mental flexibility-select EF processes that depend on the integrity of the CC system. Preliminary evidence links CC integrity to daily functioning in OABD; accelerated aging decline in CC may pose a mechanism for high risk of functional impairment and dementia in OABD.

Case series of diagnostic shift from bipolar disorder to schizoaffective disorder

OBJECTIVE

To describe three cases of diagnostic shift from bipolar I disorder (BD) to schizoaffective disorder (SAD).

METHODS

BD patients were clinically assessed and followed up in a mood disorder program. A questionnaire was applied to assess clinical and socio-demographic characteristics, and a Structured Clinical Interview (SCID-I) was conducted.

RESULTS

We identified three patients with diagnosis conversion to SAD from 2005 to 2016. The mean time between BD diagnosis and the diagnostic shift to SAD was 9 years.

CONCLUSIONS

Psychotic symptoms may become persistent, chronic and unrelated to the presence of mood episodes many years after the beginning of BD. Psychiatrists should be aware of this and reassess the diagnosis during the longitudinal course of BD, especially in those patients who present psychotic symptoms.

Test-retest reliability of the diagnosis of schizoaffective disorder in childhood and adolescence - A systematic review and meta-analysis

OBJECTIVES

Reliability of schizoaffective disorder (SAD) diagnoses is low in adults but unclear in children and adolescents (CAD). We estimate the test-retest reliability of SAD and its key differential diagnoses (schizophrenia, bipolar disorder, and unipolar depression).

METHODS

Systematic literature search of Medline, Embase, and PsycInfo for studies on test-retest reliability of SAD, in CAD. Cohen's kappa was extracted from studies. We performed meta-analysis for kappa, including subgroup and sensitivity analysis (PROSPERO protocol: CRD42013006713).

RESULTS

Out of > 4000 records screened, seven studies were included. We estimated kappa values of 0.27 [95%-CI: 0.07 0.47] for SAD, 0.56 [0.29; 0.83] for schizophrenia, 0.64 [0.55; 0.74] for bipolar disorder, and 0.66 [0.52; 0.81] for unipolar depression. In 5/7 studies kappa of SAD was lower than that of schizophrenia; similar trends emerged for bipolar disorder (4/5) and unipolar depression (2/3). Estimates of positive agreement of SAD diagnoses supported these results.

LIMITATIONS

The number of studies and patients included is low.

CONCLUSIONS

The point-estimate of the test-retest reliability of schizoaffective disorder is only fair, and lower than that of its main differential diagnoses. All kappa values under study were lower in children and adolescents samples than those reported for adults. Clinically, schizoaffective disorder should be diagnosed in strict adherence to the operationalized criteria and ought to be re-evaluated regularly. Should larger studies confirm the insufficient reliability of schizoaffective disorder in children and adolescents, the clinical value of the diagnosis is highly doubtful.

Psychopathological and demographic characteristics of hallucinating patients with schizophrenia and schizoaffective disorder: an analysis based on AMDP data

Hallucinations are at the core of the diagnosis of schizophrenia and schizoaffective disorders, and many neuroscience studies focus on hallucinations. However, there is a lack of data on prevalence, subtyping, and clinical correlates of hallucinations as well as on the comparison of hallucinating schizophrenia versus hallucinating schizoaffective patients. Analysis of all psychopathology evaluations is based on the AMDP scale in a German psychiatric university hospital between 2007 and 2013 regarding patients with schizophrenia or schizoaffective disorder (diagnosed according to ICD-10). Hallucinating versus non-hallucinating patients and age- and gender-matched hallucinating schizophrenic versus schizoaffective patients were compared with regard to key psychopathological and demographic characteristics. Relative to patients with schizoaffective disorder, patients with schizophrenia more often hallucinated at admission (36.6 vs. 16.2 %, RR: 2.3, p < 0.001). By subtype, frequency of hallucinations ranked auditory verbal > other auditory > visual > somatic/tactile > olfactory/gustatory. Hallucinating patients of either disorder were more often affected with respect to delusions (83 vs. 62 % and 81 vs. 48 % among patients with schizophrenia and schizoaffective disorder, respectively [both p < 0.0001]) and anxiety. Hallucinating patients with schizoaffective disorder did not differ from hallucinating patients with schizophrenia. This is one of the few studies providing data on hallucinations in a routine clinical care setting. Hallucinations are a sign and likely a cause of greater illness severity. Patients with schizoaffective disorder less often experience hallucinations than patients with schizophrenia, but if they do, they seem to resemble patients with schizophrenia with regard to illness severity.