Prognostic value of initial subtype in schizophrenic disorders

Disorganization domain as a putative predictor of Treatment Resistant Schizophrenia (TRS) diagnosis: A machine learning approach

BACKGROUND

Treatment Resistant Schizophrenia (TRS) is the persistence of significant symptoms despite adequate antipsychotic treatment. Although consensus guidelines are available, this condition remains often unrecognized and an average delay of 4-9 years in the initiation of clozapine, the gold standard for the pharmacological treatment of TRS, has been reported. We aimed to determine through a machine learning approach which domain of the Positive and Negative Syndrome Scale (PANSS) 5-factor model was most associated with TRS.

METHODS

In a cross-sectional design, 128 schizophrenia patients were classified as TRS (n = 58) or non-TRS (n = 60) after a structured retrospective-prospective analysis of treatment response. The random forest algorithm (RF) was trained to analyze the relationship between the presence/absence of TRS and PANSS-based psychopathological factor scores (positive, negative, disorganization, excitement, and emotional distress). As a complementary strategy to identify the variables most associated with the diagnosis of TRS, we included the variables selected by the RF algorithm in a multivariate logistic regression model.

RESULTS

according to the RF model, patients with higher disorganization, positive, and excitement symptom scores were more likely to be classified as TRS. The model showed an accuracy of 67.19%, a sensitivity of 62.07%, and a specificity of 71.43%, with an area under the curve (AUC) of 76.56%. The multivariate model including disorganization, positive, and excitement factors showed that disorganization was the only factor significantly associated with TRS. Therefore, the disorganization factor was the variable most consistently associated with the diagnosis of TRS in our sample.

Molecular and cellular mechanisms leading to catatonia: an integrative approach from clinical and preclinical evidence

This review aims to describe the clinical spectrum of catatonia, in order to carefully assess the involvement of astrocytes, neurons, oligodendrocytes, and microglia, and articulate the available preclinical and clinical evidence to achieve a translational understanding of the cellular and molecular mechanisms behind this disorder. Catatonia is highly common in psychiatric and acutely ill patients, with prevalence ranging from 7.6% to 38%. It is usually present in different psychiatric conditions such as mood and psychotic disorders; it is also a consequence of folate deficiency, autoimmunity, paraneoplastic disorders, and even autistic spectrum disorders. Few therapeutic options are available due to its complexity and poorly understood physiopathology. We briefly revisit the traditional treatments used in catatonia, such as antipsychotics, electroconvulsive therapy, and benzodiazepines, before assessing novel therapeutics which aim to modulate molecular pathways through different mechanisms, including NMDA antagonism and its allosteric modulation, and anti-inflammatory drugs to modulate microglia reaction and mitigate oxidative stress, such as lithium, vitamin B12, and NMDAr positive allosteric modulators.

Catatonia as part of the psychomotor syndrome in schizophrenia

Although the prevalence and severity of catatonia may have decreased over time, it is still a highly relevant, frequently occurring symptom cluster that can be observed in schizophrenia patients. Apart from this syndrome, neurological soft signs, psychomotor slowing and extrapyramidal symptoms are other psychomotor symptom clusters that are part of the clinical picture of schizophrenia. In this overview, the relevance of catatonia as a contemporary symptom cluster of the illness as well as its relationship with other psychomotor symptoms of the illness are discussed.

First rank symptoms for schizophrenia

BACKGROUND

Early and accurate diagnosis and treatment of schizophrenia may have long-term advantages for the patient; the longer psychosis goes untreated the more severe the repercussions for relapse and recovery. If the correct diagnosis is not schizophrenia, but another psychotic disorder with some symptoms similar to schizophrenia, appropriate treatment might be delayed, with possible severe repercussions for the person involved and their family. There is widespread uncertainty about the diagnostic accuracy of First Rank Symptoms (FRS); we examined whether they are a useful diagnostic tool to differentiate schizophrenia from other psychotic disorders.

OBJECTIVES

To determine the diagnostic accuracy of one or multiple FRS for diagnosing schizophrenia, verified by clinical history and examination by a qualified professional (e.g. psychiatrists, nurses, social workers), with or without the use of operational criteria and checklists, in people thought to have non-organic psychotic symptoms.

SEARCH METHODS

We conducted searches in MEDLINE, EMBASE, and PsycInfo using OvidSP in April, June, July 2011 and December 2012. We also searched MEDION in December 2013.

SELECTION CRITERIA

We selected studies that consecutively enrolled or randomly selected adults and adolescents with symptoms of psychosis, and assessed the diagnostic accuracy of FRS for schizophrenia compared to history and clinical examination performed by a qualified professional, which may or may not involve the use of symptom checklists or based on operational criteria such as ICD and DSM.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened all references for inclusion. Risk of bias in included studies were assessed using the QUADAS-2 instrument. We recorded the number of true positives (TP), true negatives (TN), false positives (FP), and false negatives (FN) for constructing a 2 x 2 table for each study or derived 2 x 2 data from reported summary statistics such as sensitivity, specificity, and/or likelihood ratios.

MAIN RESULTS

We included 21 studies with a total of 6253 participants (5515 were included in the analysis). Studies were conducted from 1974 to 2011, with 80% of the studies conducted in the 1970's, 1980's or 1990's. Most studies did not report study methods sufficiently and many had high applicability concerns. In 20 studies, FRS differentiated schizophrenia from all other diagnoses with a sensitivity of 57% (50.4% to 63.3%), and a specificity of 81.4% (74% to 87.1%) In seven studies, FRS differentiated schizophrenia from non-psychotic mental health disorders with a sensitivity of 61.8% (51.7% to 71%) and a specificity of 94.1% (88% to 97.2%). In sixteen studies, FRS differentiated schizophrenia from other types of psychosis with a sensitivity of 58% (50.3% to 65.3%) and a specificity of 74.7% (65.2% to 82.3%).

AUTHORS' CONCLUSIONS

The synthesis of old studies of limited quality in this review indicates that FRS correctly identifies people with schizophrenia 75% to 95% of the time. The use of FRS to diagnose schizophrenia in triage will incorrectly diagnose around five to 19 people in every 100 who have FRS as having schizophrenia and specialists will not agree with this diagnosis. These people will still merit specialist assessment and help due to the severity of disturbance in their behaviour and mental state. Again, with a sensitivity of FRS of 60%, reliance on FRS to diagnose schizophrenia in triage will not correctly diagnose around 40% of people that specialists will consider to have schizophrenia. Some of these people may experience a delay in getting appropriate treatment. Others, whom specialists will consider to have schizophrenia, could be prematurely discharged from care, if triage relies on the presence of FRS to diagnose schizophrenia. Empathetic, considerate use of FRS as a diagnostic aid - with known limitations - should avoid a good proportion of these errors.We hope that newer tests - to be included in future Cochrane reviews - will show better results. However, symptoms of first rank can still be helpful where newer tests are not available - a situation which applies to the initial screening of most people with suspected schizophrenia. FRS remain a simple, quick and useful clinical indicator for an illness of enormous clinical variability.

Influence of antipsychotic treatment type and regimen on the functionality of patients with schizophrenia

BACKGROUND

Enhanced functionality is a major goal in the treatment of schizophrenia. However, possible differences in the effectiveness of first- vs. second-generation antipsychotics or between depot/long-acting injectable (D/LAI) vs. D/LAI plus oral antipsychotics are not clear.

AIMS

This study was designed to evaluate possible differences between the effects of different antipsychotic treatment types or regimens on the functionality of patients with schizophrenia.

METHODS

85 outpatients with schizophrenia, who were being treated with D/LAI antipsychotics--co-administered or not with oral antipsychotics--and had been adherent to the treatment during the previous year were evaluated. Socio-demographic, clinical, treatment-related, global severity and functionality variables were evaluated. Patients were grouped according to the type of antipsychotic drug (first- vs. second-generation) or according to the co-administration (or not) of oral antipsychotics.

RESULTS

No differences were found between first- and second-generation antipsychotics in terms of global functionality. Patients treated with LAI risperidone showed better global functionality and better performance in their habitual social activities and personal-social relationships than patients treated with risperidone plus oral second-generation antipsychotics. Better functionality was also found to be associated with higher education level, paranoid subtype of schizophrenia, harmful use of nicotine, adherence to oral treatment and absence of concomitant oral anticholinergic or psychopharmacological treatment.

CONCLUSIONS

Our results suggest that D/LAI antipsychotic treatments should be administered in monotherapy whenever possible and that the treatment schedule should be simple, in order to achieve better functionality.

Prevalence of the catatonic syndrome in an acute inpatient sample

OBJECTIVE

In this exploratory open label study, we investigated the prevalence of catatonia in an acute psychiatric inpatient population. In addition, differences in symptom presentation of catatonia depending on the underlying psychiatric illness were investigated.

METHODS

One hundred thirty patients were assessed with the Bush-Francis Catatonia Rating Scale (BFCRS), the Positive and Negative Syndrome Scale, the Young Mania Rating Scale, and the Simpson-Angus Scale. A factor analysis was conducted in order to generate six catatonic symptom clusters. Composite scores based on this principal component analysis were calculated.

RESULTS

When focusing on the first 14 items of the BFCRS, 101 patients (77.7%) had at least 1 symptom scoring 1 or higher, whereas, 66 patients (50.8%) had at least 2 symptoms. Interestingly, when focusing on the DSM-5 criteria of catatonia, 22 patients (16.9%) could be considered for this diagnosis. Furthermore, different symptom profiles were found, depending on the underlying psychopathology. Psychotic symptomatology correlated strongly with excitement symptomatology (r = 0.528, p < 0.001) and to a lesser degree with the stereotypy/mannerisms symptom cluster (r = 0.289; p = 0.001) and the echo/perseveration symptom cluster (r = 0.185; p = 0.035). Similarly, manic symptomatology correlated strongly with the excitement symptom cluster (r = 0.596; p < 0.001) and to a lesser extent with the stereotypy/mannerisms symptom cluster (r = 0.277; p = 0.001).

CONCLUSION

There was a high prevalence of catatonic symptomatology. Depending on the criteria being used, we noticed an important difference in exact prevalence, which makes it clear that we need clear-cut criteria. Another important finding is the fact that the catatonic presentation may vary depending on the underlying pathology, although an unambiguous delineation between these catatonic presentations cannot be made. Future research is needed to determine diagnostical criteria of catatonia, which are clinically relevant.

The diagnostic status of first-rank symptoms

OBJECTIVE

In the International Statistical Classification of Diseases, Tenth Revision(ICD-10) and Diagnostic and Statistical Manual of Mental Disorder, Third and Fourth Edition(DSM-III-IV), the presence of one of Schneider "first-rank symptoms" (FRS) is symptomatically sufficient for the schizophrenia diagnosis. Yet, it has been claimed that FRS may also be found in the nonschizophrenic conditions, and therefore, they are not specific or diagnostic for schizophrenia. This review was made to clarify the issue of diagnostic specificity.

METHODS

(1) A critical review of FRS studies published in English between 1970 and 2005. (2) A highlight of the 5 most frequently cited studies identified in the Web of Science. (3) Theoretical implications of the epistemological issues of FRS.

RESULTS

The reviewed studies do not allow for either a reconfirmation or a rejection of Schneider's claims about FRS. The sources of disagreement between the studies are (1) including or excluding acute patients with potential degradation of consciousness; (2) assessing or not the phenomenological context; (3) assessing patients in different stages of their illness evolution; and (4) differential emphasis on mood symptoms and history of psychiatric symptoms.

CONCLUSION

Both DSM-IV and ICD-10 emphasize FRS to a degree that is not supported by the empirical evidence. Until the status of FRS is clarified in depth, we suggest that the FRS, as these are currently defined, should be de-emphasized in the next revisions of our diagnostic systems. Future studies aiming at validation of FRS as diagnostic features need to apply a phenomenological perspective and include a homogenous group of patients across a wide spectrum of diagnoses.

Competing definitions of schizophrenia: what can be learned from polydiagnostic studies?

The contemporary diagnoses of schizophrenia (sz)-Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition(DSM-IV) and International Classification of Diseases, 10th Revision(ICD-10)-are widely considered as important scientific achievements. However, these algorithms were not a product of explicit conceptual analyses and empirical studies but defined through consensus with the purpose of improving reliability. The validity status of current definitions and of their predecessors remains unclear. The so-called "polydiagnostic approach" applies different definitions of a disorder to the same patient sample in order to compare these definitions on potential validity indicators. We reviewed 92 polydiagnostic sz studies published since the early 1970s. Different sz definitions show a considerable variation concerning frequency, concordance, reliability, outcome, and other validity measures. The DSM-IV and the ICD-10 show moderate reliability but both definitions appear weak in terms of concurrent validity, eg, with respect to an aggregation of a priori important features. The first-rank symptoms of Schneider are not associated with family history of sz or with prediction of poor outcome. The introduction of long duration criteria and exclusion of affective syndromes tend to restrict the diagnosis to chronic stable patients. Patients fulfilling the majority of definitions (core sz patients) do not seem to constitute a strongly valid subgroup but rather a severely ill subgroup. Paradoxically, it seems that a century after the introduction of the sz concept, research is still badly needed, concerning conceptual and construct validity of sz, its essential psychopathological features, and phenotypic boundaries.

Inverse relation between clinical distractibility and Stroop interference in functional psychoses

INTRODUCTION

Many patients with psychotic disorders appear distractible. Some theories propose that distractibility causes psychotic symptoms, others propose the reverse. We tested these theories by assessing relations between psychotic symptoms, Stroop interference, and clinical distractibility in patients with schizophrenia or affective psychoses.

METHODS

We rated clinical distractibility in patients with acute schizophrenia or affective psychoses and measured their Stroop interference in a single trial colour-naming task.

RESULTS

Clinical distractibility related inversely to Stroop interference. Stroop interference was small in drug-naive patients with schizophrenia, but normal in those receiving treatment. Patients with affective psychoses showed the opposite pattern.

CONCLUSIONS

The abnormality of attention that clinicians rate as "distractibility" is probably the opposite-attentional capture. Abnormal attention neither results from nor causes psychotic symptoms. Rather, it is an independent correlate of pathophysiology in functional psychoses that merits assessment and treatment in its own right.

Is paranoid status prognostic of good outcomes? It depends

Better outcomes for psychiatric inpatients classified as paranoid rather than nonparanoid could be due to group differences in disability levels created by traditional classification approaches. Paranoid functioning, per se, may not predict good institutional outcomes. The authors retrieved community outcome data for 469 inpatients from 19 wards, a subsample of participants that had been previously examined during their inpatient stay. Paranoid groups showed better community outcomes as an artifact of differences in disability levels when classifications were based on the traditional approach that requires a predominance of paranoid over nonparanoid behavior. No differential outcomes appeared when classifications were based on dimensionally measured paranoid functioning alone. In fact, dispositions of patients suggest that staff view paranoid behavior as a negative rather than positive prognostic indicator.

Heterogeneity in functional status among older outpatients with schizophrenia: employment history, living situation, and driving

Schizophrenia and aging are both risk factors for deficits in independent functioning, yet relatively few studies have examined the level and predictors of functional status of older outpatients with schizophrenia. We compared employment history, current living situation, and driving status of 83 middle-aged and elderly outpatients with schizophrenia (mean age 59 years), and 46 demographically equivalent normal comparison subjects. We also examined the relationships of neuropsychological functioning and psychiatric symptoms to these aspects of everyday functioning. The schizophrenia patient group had consistently worse functional status than the normal comparison group, but 30% of the patients were employed at least 50% of the time during their post-schizophrenia-onset adult lives, 73% were living in a house or apartment and responsible for meeting most of their own daily needs, and 43% were current drivers. Severity of negative symptoms (but not that of positive symptoms) was inversely correlated with functional status. Worse performance on a neuropsychological battery was generally associated with worse functional status. These findings counter notions that functional impairment is inevitable in older schizophrenia patients, and highlight the importance of assessment of functional skills and possibly targeting them as a treatment focus.

[Disability in schizophrenia. Intrinsic factors and prediction of psychosocial outcome. An analysis of literature]

OBJECTIVE

Many different factors, both related to the individual and illness ("intrinsic" factors) and to the environment ("extrinsic" factors), contribute in different ways to the development of disability. Basing on data of literature, this review focuses the main "intrinsic" factors predicting disability in schizophrenia.

METHOD

A systematic search on Mediline of all papers published during the period 1965-2001 was performed, using "schizophrenia", "outcome", "psychosocial outcome", "social disability" and "social adjustment" as key words. Only papers reporting specifically data about predictive factors and psychosocial outcome variables were considered; prospective follow-up studies were considered, but retrospective and cross-sectional studies were also taken into account when data deriving from prospective studies were inconsistent.

RESULTS

Male sex predicts a higher disability among demographic factors; lower social and occupational adjustment are premorbid personality factors associated with higher disability; among factors related to illness, younger age at onset of illness, "nuclear", "non paranoid" and in particular "deficit" forms of schizophrenia seem to predict more disability. The latter seems to be predicted also by higher levels of negative symptoms and neuropsychological deficits; the role of depressive symptoms seems to be less supported by follow-up data; a continuous course of the illness predicts more disability, although some evidences show a progressive reduction of disability, at least in the long term.

CONCLUSIONS

Disability shows a largely autonomous course respect to symptoms and has to be considered an independent parameter of outcome. Few intrinsic factors show a predictive role also in the long term.

Predicting the long-term outcome of schizophrenia

Predictors of long-term (13 year) outcome of schizophrenia are reported for a representative cohort of 'treated incidence' patients ascertained on their first contact with Nottingham psychiatric services between 1978-80. An initial (baseline) model including previously reported predictors of 2-year outcome (age, gender, ever married, acuteness of onset) and length of untreated illness was used to predict a range of outcome measures covering the domains of disability, psychopathology, hospitalization, employment, social activity, and global outcome. This model demonstrated significant prognostic ability across all non-hospitalization outcomes under both ICD-10 and ICD-9 diagnoses of schizophrenia, but was attenuated under broad (ICD-9 and CATEGO S, P or O) and restrictive (S+) diagnostic classifications. Female gender predicted more favourable outcome under all diagnostic classifications except S+. In an extended analysis, the addition of initial 2-year course type substantially increased the prognostic ability of the model under all diagnostic classifications and enabled over 30% of the variance in global ratings of disability and symptoms to be predicted. In this extended model female gender predicted more favourable outcome over and above the effect of course type, across most domains under ICD-10, and for disability and psychopathology under other diagnostic classifications. The inclusion of measures of psychopathology at the time of first assessment, pre-morbid functioning, and duration of index admission conferred only marginal additional predictive ability for respective outcomes in the domains of psychopathology, social activity, employment and hospitalization. Hospitalization during the past year was the most difficult outcome to predict under any model suggesting that resource utilization represents the 'administrative outcome' of schizophrenia and serves as a poor proxy for broader concerns in the era of community care. These data demonstrate that key demographic variables and the mode of onset influence the long-term course of schizophrenia, but that early course type is a particularly strong predictor.

Subtypes in schizophrenic disorders: frequencies in long-term course and premorbid features

The subclassification of schizophrenic disorders according to four diagnostic systems (DSM-III-R, ICD-10, the positive vs. negative dichotomy and Schneider's first rank symptoms) was compared over the long-term course of the disease in 148 narrowly defined schizophrenic patients. A total of 595 episodes were classified over a mean observation period of 23 years (range 10-50 years). Initially, paranoid/positive subtypes predominated, while later in the course episodes fulfilling the symptomatological criteria of residual/negative subtypes became more frequent. Disorganised/hebephrenic and catatonic subtypes were found to be rare. Some premorbid features were investigated as non-symptomatological validators for subclassification. Significant differences were found with regard to age at onset. Patients whose first episode was paranoid or positive had the highest age at onset. Patients with initial disorganised/hebephrenic or "residual" episodes had the most unfavourable premorbid social adjustment, even when the influence of age at onset was discounted. The diagnostic systems investigated showed similarities and differences as a result of the underlying concepts. Methodological implications are discussed.