Episodic and residual thought pathology in chronic schizophrenics: effect of neuroleptics

Exploring the conceptualisation, measurement, clinical utility and treatment of formal thought disorder in psychosis: A Delphi study

BACKGROUND

Formal Thought Disorder (FTD) is a recognised psychiatric symptom, yet its characterisation remains debated. This is problematic because it contributes to poor efficiency and heterogeneity in psychiatric research, with salient clinical impact.

OBJECTIVE

This study aimed to investigate expert opinion on the concept, measurement and clinical utility of FTD using the Delphi technique.

METHOD

Across three rounds, experts were queried on their definitions of FTD, methods for the assessment and measurement of FTD, associated clinical outcomes and treatment options.

RESULTS

Responses were obtained from 56 experts, demonstrating varying levels of consensus across different aspects of FTD. While consensus (>80 %) was reached for some aspects on the concept of FTD, including its definition and associated symptomology and mechanisms, others remained less clear. Overall, the universal importance attributed to the clinical understanding, measurement and treatment of FTD was clear, although consensus was infrequent as to the reasons behind and methods for doing so.

CONCLUSIONS

Our results contribute to the still elusive formal definition of FTD. The multitude of interpretations regarding these topics highlights the need for further clarity with this phenomenon. Our findings emphasised that the measurement and clinical utility of FTD are closely tied to the concept; hence, until there is agreement on the concept of FTD, difficulties with measuring and understanding its clinical usefulness to inform treatment interventions will persist. Future FTD research should focus on clarifying the factor structure and dimensionality to determine the latent structure and elucidate the core clinical phenotype.

Dissecting the neurobiology of linguistic disorganisation and impoverishment in schizophrenia

Schizophrenia provides a quintessential disease model of how disturbances in the molecular mechanisms of neurodevelopment lead to disruptions in the emergence of cognition. The central and often persistent feature of this illness is the disorganisation and impoverishment of language and related expressive behaviours. Though clinically more prominent, the periodic perceptual distortions characterised as psychosis are non-specific and often episodic. While several insights into psychosis have been gained based on study of the dopaminergic system, the mechanistic basis of linguistic disorganisation and impoverishment is still elusive. Key findings from cellular to systems-level studies highlight the role of ubiquitous, inhibitory processes in language production. Dysregulation of these processes at critical time periods, in key brain areas, provides a surprisingly parsimonious account of linguistic disorganisation and impoverishment in schizophrenia. This review links the notion of excitatory/inhibitory (E/I) imbalance at cortical microcircuits to the expression of language behaviour characteristic of schizophrenia, through the building blocks of neurochemistry, neurophysiology, and neurocognition.

Cognitive correlates of 'Formal Thought Disorder' in a non-clinical sample with elevated schizotypal traits

Different dimensions of formal thought disorder (FTD) are distinguished by different patterns of cognitive dysfunction in patients with schizophrenia; however, inconsistent findings may relate to patient-related confounds. To avoid these confounds, we examined relationships between FTD dimensions and cognitive domains in a non-clinical sample with attenuated schizophrenia-like traits, or schizotypal traits, on the Schizotypal Personality Questionnaire (N = 91). To our knowledge, no study has done this. FTD dimension scores were derived following principal component analysis of the Scale for the Assessment of Thought, Language and Communication (TLC dimensions: Disorganisation, Verbosity, Emptiness) and the Thought and Language Index (TLI dimensions: Negative, Idiosyncratic). The sample completed a comprehensive neuropsychological battery. Findings indicate that higher-order reasoning, executive function (set shift and generative ability) and language/semantic functioning are the primary drivers of FTD in our non-clinical sample with elevated schizotypal traits, in line with schizophrenia research. FTD may have shared aetiology along the schizophrenia spectrum.

A historical review of placebo-controlled, relapse prevention trials in schizophrenia: The loss of clinical equipoise

Recent ethical critiques have proposed that placebo-controlled, relapse prevention trials in schizophrenia are no longer justifiable and are therefore unethical. This review provides an historical perspective on the justifications for these trials and how arguments evolved over several decades. We identified 87 placebo-controlled, relapse prevention trials published over the last seventy years and examined the purpose for each trial. We found that first-generation trials had compelling justifications, yet these arguments changed considerably over time. Second-generation trials offered comparatively weaker-and sometimes no-justifications for their conduct. Without clear and compelling justifications for a given trial, it is not ethical to continue using this study design.

Motor-related oscillatory activity in schizophrenia according to phase of illness and clinical symptom severity

Magnetoencephalography (MEG) measures magnetic fields generated by synchronised neural current flow and provides direct inference on brain electrophysiology and connectivity, with high spatial and temporal resolution. The movement-related beta decrease (MRBD) and the post-movement beta rebound (PMBR) are well-characterised effects in magnetoencephalography (MEG), with the latter having been shown to relate to long-range network integrity. Our previous work has shown that the PMBR is diminished (relative to controls) in a group of schizophrenia patients. However, little is known about how this effect might differ in patients at different stages of illness and degrees of clinical severity. Here, we extend our previous findings showing that the MEG derived PMBR abnormality in schizophrenia exists in 29 recent-onset and 35 established cases (i.e., chronic patients), compared to 42 control cases. In established cases, PMBR is negatively correlated with severity of disorganization symptoms. Further, using a hidden Markov model analysis, we show that transient pan-spectral oscillatory "bursts", which underlie the PMBR, differ between healthy controls and patients. Results corroborate that PMBR is associated with disorganization of mental activity in schizophrenia.

Definitions of relapse in trials comparing antipsychotic maintenance with discontinuation or reduction for schizophrenia spectrum disorders: A systematic review

INTRODUCTION

Avoidance of relapse is the main aim of long-term antipsychotic treatment in schizophrenia, yet how 'relapse' is defined in trials is not well-known.

METHODS

We conducted a systematic review of definitions of relapse in trials of continuous antipsychotic treatment compared with discontinuation, intermittent treatment or dose reduction for people with schizophrenia spectrum disorders. Trials were identified from previous Cochrane reviews and a new search. The quality of relapse definitions was rated in terms of reliability and clinical relevance and associations between quality of definitions and trial characteristics and outcome were explored.

RESULTS

We identified 82 reports of 81 trials which employed 54 different definitions of relapse. There were 33 definitions in the 35 trials published since 1990, with recent trials employing complex definitions often involving alternative criteria. Only ten primary definitions of relapse required the presence of psychotic symptoms in all cases, and only three specified this in combination with a measure of overall severity or functional decline. Only two definitions specified a duration longer than two days. Relapse definitions were rated as showing good reliability in 37 trials, but only seven showed good clinical relevance. Six trials with definitions that were both reliable and clinically relevant were slightly longer, but did not differ from remaining trials in other characteristics or overall or relative risk of relapse.

CONCLUSIONS

Antipsychotic trials define relapse in numerous different ways, and few definitions consistently reflect suggested indications of a clinically significant relapse.

Maintenance treatment with antipsychotic drugs for schizophrenia

BACKGROUND

The symptoms and signs of schizophrenia have been linked to high levels of dopamine in specific areas of the brain (limbic system). Antipsychotic drugs block the transmission of dopamine in the brain and reduce the acute symptoms of the disorder. An original version of the current review, published in 2012, examined whether antipsychotic drugs are also effective for relapse prevention. This is the updated version of the aforesaid review.

OBJECTIVES

To review the effects of maintaining antipsychotic drugs for people with schizophrenia compared to withdrawing these agents.

SEARCH METHODS

We searched the Cochrane Schizophrenia Group's Study-Based Register of Trials including the registries of clinical trials (12 November 2008, 10 October 2017, 3 July 2018, 11 September 2019).

SELECTION CRITERIA

We included all randomised trials comparing maintenance treatment with antipsychotic drugs and placebo for people with schizophrenia or schizophrenia-like psychoses.

DATA COLLECTION AND ANALYSIS

We extracted data independently. For dichotomous data we calculated risk ratios (RR) and their 95% confidence intervals (CIs) on an intention-to-treat basis based on a random-effects model. For continuous data, we calculated mean differences (MD) or standardised mean differences (SMD), again based on a random-effects model.

MAIN RESULTS

The review currently includes 75 randomised controlled trials (RCTs) involving 9145 participants comparing antipsychotic medication with placebo. The trials were published from 1959 to 2017 and their size ranged between 14 and 420 participants. In many studies the methods of randomisation, allocation and blinding were poorly reported. However, restricting the analysis to studies at low risk of bias gave similar results. Although this and other potential sources of bias limited the overall quality, the efficacy of antipsychotic drugs for maintenance treatment in schizophrenia was clear. Antipsychotic drugs were more effective than placebo in preventing relapse at seven to 12 months (primary outcome; drug 24% versus placebo 61%, 30 RCTs, n = 4249, RR 0.38, 95% CI 0.32 to 0.45, number needed to treat for an additional beneficial outcome (NNTB) 3, 95% CI 2 to 3; high-certainty evidence). Hospitalisation was also reduced, however, the baseline risk was lower (drug 7% versus placebo 18%, 21 RCTs, n = 3558, RR 0.43, 95% CI 0.32 to 0.57, NNTB 8, 95% CI 6 to 14; high-certainty evidence). More participants in the placebo group than in the antipsychotic drug group left the studies early due to any reason (at seven to 12 months: drug 36% versus placebo 62%, 24 RCTs, n = 3951, RR 0.56, 95% CI 0.48 to 0.65, NNTB 4, 95% CI 3 to 5; high-certainty evidence) and due to inefficacy of treatment (at seven to 12 months: drug 18% versus placebo 46%, 24 RCTs, n = 3951, RR 0.37, 95% CI 0.31 to 0.44, NNTB 3, 95% CI 3 to 4). Quality of life might be better in drug-treated participants (7 RCTs, n = 1573 SMD -0.32, 95% CI to -0.57 to -0.07; low-certainty evidence); probably the same for social functioning (15 RCTs, n = 3588, SMD -0.43, 95% CI -0.53 to -0.34; moderate-certainty evidence). Underpowered data revealed no evidence of a difference between groups for the outcome 'Death due to suicide' (drug 0.04% versus placebo 0.1%, 19 RCTs, n = 4634, RR 0.60, 95% CI 0.12 to 2.97,low-certainty evidence) and for the number of participants in employment (at 9 to 15 months, drug 39% versus placebo 34%, 3 RCTs, n = 593, RR 1.08, 95% CI 0.82 to 1.41, low certainty evidence). Antipsychotic drugs (as a group and irrespective of duration) were associated with more participants experiencing movement disorders (e.g. at least one movement disorder: drug 14% versus placebo 8%, 29 RCTs, n = 5276, RR 1.52, 95% CI 1.25 to 1.85, number needed to treat for an additional harmful outcome (NNTH) 20, 95% CI 14 to 50), sedation (drug 8% versus placebo 5%, 18 RCTs, n = 4078, RR 1.52, 95% CI 1.24 to 1.86, NNTH 50, 95% CI not significant), and weight gain (drug 9% versus placebo 6%, 19 RCTs, n = 4767, RR 1.69, 95% CI 1.21 to 2.35, NNTH 25, 95% CI 20 to 50).

AUTHORS' CONCLUSIONS

For people with schizophrenia, the evidence suggests that maintenance on antipsychotic drugs prevents relapse to a much greater extent than placebo for approximately up to two years of follow-up. This effect must be weighed against the adverse effects of antipsychotic drugs. Future studies should better clarify the long-term morbidity and mortality associated with these drugs.

Quantifying the Core Deficit in Classical Schizophrenia

In the classical descriptions of schizophrenia, Kraepelin and Bleuler recognized disorganization and impoverishment of mental activity as fundamental symptoms. Their classical descriptions also included a tendency to persisting disability. The psychopathological processes underlying persisting disability in schizophrenia remain poorly understood. The delineation of a core deficit underlying persisting disability would be of value in predicting outcome and enhancing treatment. We tested the hypothesis that mental disorganization and impoverishment are associated with persisting impairments of cognition and role function, and together reflect a latent core deficit that is discernible in cases diagnosed by modern criteria. We used Confirmatory Factor Analysis to determine whether measures of disorganization, mental impoverishment, impaired cognition, and role functioning in 40 patients with schizophrenia represent a single latent variable. Disorganization scores were computed from the variance shared between disorganization measures from 3 commonly used symptom scales. Mental impoverishment scores were computed similarly. A single factor model exhibited a good fit, supporting the hypothesis that these measures reflect a core deficit. Persisting brain disorders are associated with a reduction in post-movement beta rebound (PMBR), the characteristic increase in electrophysiological beta amplitude that follows a motor response. Patients had significantly reduced PMBR compared with healthy controls. PMBR was negatively correlated with core deficit score. While the symptoms constituting impoverished and disorganized mental activity are dissociable in schizophrenia, nonetheless, the variance that these 2 symptom domains share with impaired cognition and role function, appears to reflect a pathophysiological process that might be described as the core deficit of classical schizophrenia.

Principal-component analysis of PANSS and SANS - SAPS global ratings in schizophrenic patients

The aim of this study was to test whether a positive and a negative component could be found in broadly defined schizophrenic patients. Therefore, 70 patients either in an exacerbated or in a stabilized phase were selected according to the criteria of at least 1 of the 4 following diagnostic systems: DSM III-R, Schneider, Carpenter, Langfeldt; principal component analyses (PCA) were carried out with the 9 global ratings of the Scales for Assessment of Negative and Positive Symptoms (SANS and SAPS) and with the Positive and Negative Syndrome Scale (PANSS). The PCA of the SANS-SAPS global ratings yielded a 3-factor solution explaining 72.14% of the total variance, depicting a negative, a positive and a disorganization component. The PCA of the PANSS provided a 5-factor solution with a total explained variance of 55.98%. The first 3 factors were similar to those of the SANS-SAPS global rating analysis. The results showed that the positive and negative components described in a homogeneous schizophrenic population could be replicated in a larger and more heterogeneous group of schizophrenic patients. The question regarding the sufficiency of the positive-negative dichotomy was strengthened by the presence of a third disorganization component which explained as much of the variance as the positive component.

The Complex Relationship Among Formal Thought Disorders, Neurocognition, and Functioning in Nonacutely Ill Schizophrenia Patients

The aims of the present study were to 1) evaluate clinical differences between patients suffering from schizophrenia (SZ) with mild versus moderate/severe formal thought disorder (FTD); 2) explore relationships between dimensions of FTD, neuropsychological domains, and global functioning; and 3) compare clinical dimensions of FTD in early and late SZ. One hundred thirty-six individuals with schizophrenia were recruited and evaluated during a nonacute phase of illness. FTD was assessed with the Thought, Language, and Communication Scale. Partial correlations, t-tests, and stepwise regression were undertaken to address the study aims. Patients with moderate/severe FTD performed worse than those with mild FTD for processing speed, reasoning and problem solving, and social cognition, and demonstrated poorer global functioning. Early SZ did not differ from late SZ in terms of negative FTD and difficulty in abstract thinking (DAT). Negative FTD was correlated with reasoning and problem solving; DAT was correlated with social cognition. All clinical dimensions of FTD, regardless of neurocognitive impairment, accounted for a significant amount of variance in global functioning. FTD predicted global functioning, regardless of neurocognitive factors. Due to their stability in different phases of the course of the disease and their strong relationship with other core variables, Neg-FTD and DAT should be investigated as an intermediate phenotype of the illness.

The Core Deficit of Classical Schizophrenia: Implications for Predicting the Functional Outcome of Psychotic Illness and Developing Effective Treatments

Many people suffering from psychotic illnesses experience persisting impairment of occupational and social function. Evidence assembled since the classical description of schizophrenia over a century ago indicates that both disorganization and impoverishment of mental activity are associated with persisting impairment. Longitudinal studies of young people at risk of schizophrenia reveal that both mental impoverishment and disorganization predict poor long-term outcome. These clinical features are related to cognitive impairments. Evidence from brain imaging indicates overlap in the brain abnormalities implicated in these phenomena, including impaired function of long-range connections between sensory cortex and the salience network, a network engaged in recruiting cerebral systems for processing of information salient to current circumstances. The evidence suggests that the common features underlying these two groups of symptoms might reflect a core pathological process distinguishing nonaffective from affective psychosis. This pathological process might therefore justifiably be designated the "core deficit" of classical schizophrenia. To develop more effective treatments to prevent persisting disability, we require the ability to identify individuals at risk at an early stage. Recent studies provide pointers toward effective strategies for identifying cases at risk of poor outcome. Accumulating evidence confirms that appreciable potential for neuroplastic change in the brain persists into adult life. Furthermore, brain function can be enhanced by targeted neuromodulation treatments. We now have promising tools not only for investigating the psychological and neural mechanisms that underlie persisting functional impairment but also for identifying individuals at risk and for harnessing brain plasticity to improve treatment.

Formal thought disorders: from phenomenology to neurobiology

Formal thought disorder (FTD) is present in most psychiatric disorders and in some healthy individuals. In this Review, we present a comprehensive, integrative, and multilevel account of what is known about FTD, covering genetic, cellular, and neurotransmitter effects, environmental influences, experimental psychology and neuropsychology, brain imaging, phenomenology, linguistics, and treatment. FTD is a dimensional, phenomenologically defined construct, which can be clinically subdivided into positive versus negative and objective versus subjective symptom clusters. Because FTDs have been traditionally linked to schizophrenia, studies in other diagnoses are scarce. Aetiologically, FTD is the only symptom under genetic influence in schizophrenia as shown in linkage studies, but familial communication patterns (allusive thinking) have also been associated with the condition. Positive FTDs are related to synaptic rarefication in the glutamate system of the superior and middle lateral temporal cortices. Cortical volume of the left superior temporal gyrus is decreased in patients with schizophrenia who have positive FTD in structural MRI studies and shows reversed hemispheric (right more than left) activation in functional MRI experiments during speech production. Semantic network dysfunction in positive FTD has been demonstrated in experiments of indirect semantic hyperpriming (reaction time). In acute positive FTD, antipsychotics are effective, but a subgroup of patients have treatment-resistant, chronic, positive or negative FTD. Specific psychotherapy as treatment for FTD has not yet been developed. With this solid data on the pathogenesis of FTD, we can now implement clinical studies to treat this condition.

Rethinking Thought Disorder

It has been 30 years since Holzman introduced a special issue of the Schizophrenia Bulletin entitled “Thought Disorder in Schizophrenia.” He pointed out in his Editor’s Introduction that in contrast to the explosion of interest at that time in the biological aspects of schizophrenia, there were important areas of study that represented “... relatively neglected aspects of the psychopathology of schizophrenia, namely the varieties of thinking disorders (emphasis added) characteristic of schizophrenic patients and their possible underlying mechanisms.” Perhaps presciently, he ended his introduction by expressing hope that the articles included in that issue would lead to further intensive study of the cognitive (emphasis added) dysfunctions in schizophrenia. There has, indeed, been extensive research conducted in further understanding cognitive dysfunctions in schizophrenia, but considerably less so in understanding thought disorder.

Thought Disorder in Schizophrenia and Bipolar Disorder Probands, Their Relatives, and Nonpsychiatric Controls

Thought disorder (TD) has long been associated with schizophrenia (SZ) and is now widely recognized as a symptom of mania and other psychotic disorders as well. Previous studies have suggested that the TD found in the clinically unaffected relatives of SZ, schizoaffective and bipolar probands is qualitatively similar to that found in the probands themselves. Here, we examine which quantitative measures of TD optimize the distinction between patients with diagnoses of SZ and bipolar disorder with psychotic features (BP) from nonpsychiatric controls (NC) and from each other. In addition, we investigate whether these same TD measures also distinguish their respective clinically unaffected relatives (RelSZ, RelBP) from controls as well as from each other. We find that deviant verbalizations are significantly associated with SZ and are co-familial in clinically unaffected RelSZ, but are dissociated from, and are not co-familial for, BP disorder. In contrast, combinatory thinking was nonspecifically associated with psychosis, but did not aggregate in either group of relatives. These results provide further support for the usefulness of TD for identifying potential non-penetrant carriers of SZ-risk genes, in turn enhancing the power of genetic analyses. These findings also suggest that further refinement of the TD phenotype may be needed in order to be suitable for use in genetic studies of bipolar disorder.

The prognostic value of formal thought disorder following first episode psychosis

BACKGROUND

Formal thought disorder (FTD) is associated with poor outcome in established psychotic illnesses and it can be assessed as a categorical or dimensional variable. However, its influence on functional outcome and hospitalisation patterns in early psychosis has not been investigated. We evaluated the relationship between FTD and these outcomes in a first episode psychosis (FEP) sample.

MATERIALS AND METHODS

A mixed diagnostic FEP cohort was recruited through an Early Intervention in Psychosis Service in Ireland. Participants were assessed at initial presentation and one year later with the MIRECC GAF to evaluate social and occupational functioning domains. Disorganisation (disFTD), verbosity (verFTD) and poverty (povFTD) dimensions of FTD were examined at both time points, as well as a unitary FTD construct. Analyses were controlled for demographic, clinical and treatment variables.

RESULTS

DisFTD was the only FTD dimension associated with functional outcome, specifically social functioning, on multivariate analysis (beta=0.13, P<0.05). The unitary FTD construct was not associated with functional outcome. DisFTD at FEP presentation predicted a greater number of hospitalisations (adjusted beta=0.24, P<0.001) and prolonged inpatient admission (adjusted OR=1.08, 95% CI 1.02-1.15, P<0.05) following FEP.

CONCLUSIONS

Longitudinal and dimensional evaluation of FTD has a clinical utility that is distinct from a cross-sectional or unitary assessment. Dimensions of FTD may map onto different domains of functioning. These findings are supportive of some of the changes in DSM-V with an emphasis on longitudinal and dimensional appraisal of psychopathology. Communication disorders may be considered a potential target for intervention in psychotic disorders.

Relation of formal thought disorder to symptomatic remission and social functioning in schizophrenia

OBJECTIVE

The aim of this cross-sectional study is to examine the relation of formal thought disorder (FTD) with symptomatic remission (SR) and social functioning in patients with schizophrenia.

METHOD

The study was carried out with a sample consisting of 117 patients diagnosed with schizophrenia according to DSM-IV. The patients were assessed with the Positive and Negative Syndrome Scale (PANSS), the Thought and Language Index (TLI), and the Personal and Social Performance Scale (PSP). We used logistic regression in order to determine the relation between FTD and SR and linear regression to identify the strength of association between FTD and social functioning.

RESULTS

Logistic regression analysis revealed that poverty of speech (odds ratio: 1.47, p<0.01) and peculiar logic (odds ratio: 1.66, p=0.01) differentiated the remitted patients from the non-remitted ones. Linear regression analysis showed that the PSP total score was associated with poverty of speech and peculiar logic items of the TLI (B=-0.23, p<0.01, B=-0.24, p=0.01, respectively).

CONCLUSION

Our findings suggest that poverty of speech and peculiar logic are the specific domains of FTD which are related to both SR status and social functioning in patients with schizophrenia.

Formal thought disorder in first-episode psychosis

Formal thought disorder (FTD) is one of the fundamental symptom clusters of schizophrenia and it was found to be the strongest predictor determining conversion from first-episode acute transient psychotic disorder to schizophrenia. Our goal in the present study was to compare a first-episode psychosis (FEP) sample to a healthy control group in relation to subtypes of FTD. Fifty six patients aged between 15 and 45years with FEP and forty five control subjects were included in the study. All the patients were under medication for less than six weeks or drug-naive. FTD was assessed using the Thought and Language Index (TLI), which is composed of impoverishment of thought and disorganization of thought subscales. FEP patients showed significantly higher scores on the items of poverty of speech, weakening of goal, perseveration, looseness, peculiar word use, peculiar sentence construction and peculiar logic compared to controls. Poverty of speech, perseveration and peculiar word use were the significant factors differentiating FEP patients from controls when controlling for years of education, family history of psychosis and drug abuse.

Language disturbance and functioning in first episode psychosis

Language disturbance has a central role in the presentation of psychotic disorders however its relationship with functioning requires further clarification, particularly in first episode psychosis (FEP). Both language disturbance and functioning can be evaluated with clinician-rated and performance-based measures. We aimed to investigate the concurrent association between clinician-rated and performance-based measures of language disturbance and functioning in FEP. We assessed 108 individuals presenting to an Early Intervention in Psychosis Service in Ireland. Formal thought disorder (FTD) dimensions and bizarre idiosyncratic thinking (BIT) were rated with structured assessment tools. Functioning was evaluated with a performance-based instrument, a clinician-rated measure and indicators of real-world functioning. The disorganisation dimension of FTD was significantly associated with clinician-rated measures of occupational and social functioning (Beta=-0.19, P<0.05 and Beta=-0.31, P<0.01, respectively). BIT was significantly associated with the performance-based measure of functioning (Beta=-0.22, P<0.05). Language disturbance was of less value in predicting real-world measures of functioning. Clinician-rated and performance-based assessments of language disturbance are complementary and each has differential associations with functioning. Communication disorders should be considered as a potential target for intervention in FEP, although further evaluation of the longitudinal relationship between language disturbance and functioning should be undertaken.

Distinctive Rorschach profiles of young adults with schizophrenia and autism spectrum disorder

OBJECTIVE

The differential diagnosis of schizophrenia (SZ) versus autism spectrum disorder (ASD) can be clinically challenging because accumulating evidence suggests both clinical and biological overlaps between them. The aim of this study was to compare Rorschach profiles between young adults with SZ and those with ASD.

METHODS

We evaluated quantitative tendencies on the Rorschach test among 20 patients diagnosed with SZ and 20 diagnosed with ASD. Both groups were matched for age, sex, and intelligence quotient.

RESULTS

We found significant differences in six response variables on the Rorschach comprehensive system. Those with SZ had significantly higher scores on D score, adjusted D score (Adj D), developmental quality code reflecting ordinary response (DQo), and form quality minus (FQ -) than those with ASD. In contrast, those with SZ had significantly lower scores on the active and developmental quality code reflecting synthesized response (DQ+) subscales than those with ASD.

CONCLUSION

The present findings reveal that individuals with SZ might have more stress tolerance, stronger perception distortions, and simpler and poorer recognition than those with ASD. We suggest that the Rorschach test might be a useful tool for differentiating between SZ and ASD.

Early-Onset Schizophrenia: Exploring the Contribution of the Thought Disorder Index to Clinical Assessment

Background:

Differentiating diagnostically between schizophrenia and emotional and personality disorders with psychotic or psychotic-like symptoms is a challenging task. It is especially difficult when working with adolescent patients, because their symptoms tend to manifest at lower levels as compared with adult patients. Thought disorder is a core symptom of schizophrenia, and the Rorschach Inkblot Method is widely used for the assessment of formal thought disorder.

Objective:

In this study, which is situated within ongoing clinical practice, we investigated whether the Rorschach test is helpful for assessing early-onset schizophrenia due to its ability to detect thought disorder. We also wanted to examine whether the Thought Disorder Index (TDI) is superior to the Comprehensive System (CS) for differentiating between patients with early-onset schizophrenia and non-psychotic patients experiencing auditory and visual hallucinations. An additional aim was to examine whether the TDI correlated with the Positive and Negative Syndrome Scale (PANSS).

Methods:

Twenty-three subjects between the ages of 12 and 18 years were examined with the use of the Rorschach test, and the protocols were scored according to both the TDI and the CS. All subjects were also assessed with the Positive and Negative Syndrome Scale. The sample included 14 subjects who fulfilled the criteria for schizophrenia and 9 subjects who were experiencing hallucinations that emanated from severe emotional and relational problems but who had different non-psychotic disorders.

Results:

Although the two groups could not be distinguished with regard to their total scores for thought disorder, the identification of specific thought disorder types proved useful for differential diagnosis. Verbalizations that were categorized by the TDI as “absurd responses,” “fluidity,” “contamination,” “autistic logic,” and “word-finding difficulty” were only given by patients who had been diagnosed with schizophrenia. When patients’ responses were scored with the use of the CS, the “contamination” score was the only one found to be specific to schizophrenia.

Conclusions:

Although the sample size limits the conclusions that can be drawn, the results indicate that the TDI may be superior to the CS for the identification of thought disorder specific to—but not always present in—adolescents with schizophrenia. In other words, the absence of severe thought disorder is not synonymous with the absence of severe psychopathology, but the presence of the most severe thought disorder types (i.e., “absurd responses,” “fluidity,” “incoherence,” “contamination,” and “autistic logic”) seems to be a strong indicator of schizophrenic psychopathology.

The factor structure and clinical utility of formal thought disorder in first episode psychosis

BACKGROUND

Formal thought disorder (FTD) is a core feature of psychosis, however there are gaps in our knowledge about its prevalence and factor structure. We had two aims: first, to establish the factor structure of FTD; second, to explore the clinical utility of dimensions of FTD in order to further the understanding of its nosology.

METHODS

A cross-validation study was undertaken to establish the factor structure of FTD in first episode psychosis (FEP). The relative utility of FTD categories vs. dimensions across diagnostic categories was investigated.

RESULTS

The prevalence of clinically significant FTD in this FEP sample was 21%, although 41% showed evidence of disorganised speech, 20% displayed verbosity and 24% displayed impoverished speech. A 3-factor model was identified as the best fit for FTD, with disorganisation, poverty and verbosity dimensions (GFI=0.99, RMR=0.07). These dimensions of FTD accurately distinguished affective from non-affective diagnostic categories. A categorical approach to FTD assessment was useful in identifying markers of clinical acuteness, as identified by short duration of untreated psychosis (OR=2.94, P<0.01) and inpatient treatment status (OR=3.98, P<0.01).

CONCLUSION

FTD is moderately prevalent and multi-dimensional in FEP. Employing both a dimensional and categorical assessment of FTD gives valuable clinical information, however there may be a need to revise our conceptualisation of the nosology of FTD. The prognostic value of FTD, as well as its neural basis, requires elucidation.

The linguistics of schizophrenia: thought disturbance as language pathology across positive symptoms

We hypothesize that linguistic (dis-)organization in the schizophrenic brain plays a more central role in the pathogenesis of this disease than commonly supposed. Against the standard view, that schizophrenia is a disturbance of thought or selfhood, we argue that the origins of the relevant forms of thought and selfhood at least partially depend on language. The view that they do not is premised by a theoretical conception of language that we here identify as 'Cartesian' and contrast with a recent 'un-Cartesian' model. This linguistic model empirically argues for both (i) a one-to-one correlation between human-specific thought or meaning and forms of grammatical organization, and (ii) an integrative and co-dependent view of linguistic cognition and its sensory-motor dimensions. Core dimensions of meaning mediated by grammar on this model specifically concern forms of referential and propositional meaning. A breakdown of these is virtually definitional of core symptoms. Within this model the three main positive symptoms of schizophrenia fall into place as failures in language-mediated forms of meaning, manifest either as a disorder of speech perception (Auditory Verbal Hallucinations), abnormal speech production running without feedback control (Formal Thought Disorder), or production of abnormal linguistic content (Delusions). Our hypothesis makes testable predictions for the language profile of schizophrenia across symptoms; it simplifies the cognitive neuropsychology of schizophrenia while not being inconsistent with a pattern of neurocognitive deficits and their correlations with symptoms; and it predicts persistent findings on disturbances of language-related circuitry in the schizophrenic brain.

The Epidemiology and Associated Phenomenology of Formal Thought Disorder: A Systematic Review

BACKGROUND

Authors of the Diagnostic and Statistical Manual, Fifth Edition (DSM-V) have recommended to "integrate dimensions into clinical practice." The epidemiology and associated phenomenology of formal thought disorder (FTD) have been described but not reviewed. We aimed to carry out a systematic review of FTD to this end.

METHODS

A systematic review of FTD literature, from 1978 to 2013, using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

A total of 881 abstracts were reviewed and 120 articles met inclusion criteria; articles describing FTD factor structure (n = 15), prevalence and longitudinal course (n = 41), role in diagnosis (n = 22), associated clinical variables (n = 56), and influence on outcome (n = 35) were included. Prevalence estimates for FTD in psychosis range from 5% to 91%. Dividing FTD into domains, by factor analysis, can accurately identify 91% of psychotic diagnoses. FTD is associated with increased clinical severity. Poorer outcomes are predicted by negative thought disorder, more so than the typical construct of "disorganized speech."

CONCLUSION

FTD is a common symptom of psychosis and may be considered a marker of illness severity. Detailed dimensional assessment of FTD can clarify diagnosis and may help predict prognosis.

A hierarchical finite mixture model that accommodates zero-inflated counts, non-independence, and heterogeneity

A number of mixture modeling approaches assume both normality and independent observations. However, these two assumptions are at odds with the reality of many data sets, which are often characterized by an abundance of zero-valued or highly skewed observations as well as observations from biologically related (i.e., non-independent) subjects. We present here a finite mixture model with a zero-inflated Poisson regression component that may be applied to both types of data. This flexible approach allows the use of covariates to model both the Poisson mean and rate of zero inflation and can incorporate random effects to accommodate non-independent observations. We demonstrate the utility of this approach by applying these models to a candidate endophenotype for schizophrenia, but the same methods are applicable to other types of data characterized by zero inflation and non-independence.

Thought disorder in mid-childhood as a predictor of adulthood diagnostic outcome: findings from the New York High-Risk Project

BACKGROUND

Thought disorder has been proposed as an indicator of schizotypy, which is considered to be necessary but not sufficient for the development of schizophrenia. It is unclear whether thought disorder is an indicator of susceptibility (i.e. an endophenotype) for schizophrenia. The goal of the present study was to elucidate the role of thought disorder in relation to schizotypy by examining its presence in high-risk individuals during mid-childhood. Method The sample consisted of 265 subjects drawn from the New York High-Risk Project. Individuals at high risk for schizophrenia (i.e. offspring of parents with schizophrenia) were compared with individuals at low risk for schizophrenia (i.e. offspring of parents with affective disorder or offspring of psychiatrically normal parents). Videotaped interviews were rated for thought disorder using the Scale for the Assessment of Thought, Language, and Communication (TLC). The same subjects were administered diagnostic interviews in late adolescence/early adulthood.

RESULTS

Although positive thought disorder was equally present in subjects with affective and non-affective psychoses, negative thought disorder (namely, poverty of speech and poverty of content of speech) was elevated only in subjects with schizophrenia-related psychosis. Logistic regression analyses revealed that negative thought disorder added to the prediction of schizophrenia-related psychosis outcomes over and above positive thought disorder.

CONCLUSIONS

These findings suggest that negative thought disorder may have a specific association with schizotypy, rather than a more general association with psychosis. The findings also support consideration of negative thought disorder as an endophenotypic indicator of a schizophrenia diathesis.

Cognition and communication dysfunctions in early-onset schizophrenia: effect of risperidone

BACKGROUND

Cognitive impairment and formal thought disorder, also referred to as communication disturbances, are considered the core symptoms of schizophrenia, strongly affecting social functioning and long-term outcome. Several studies in adult patients suggest improvement of both functions after the treatment with atypical antipsychotic drugs. Such medications are also used as first line treatment in early-onset schizophrenia, however their efficacy in cognitive and communication domains in this population have not been systematically assessed.

AIM OF THE STUDY

Evaluation of risperidone efficacy at psychopathological symptoms, cognitive impairment and formal thought disorder in adolescents with schizophrenia spectrum diagnosis.

MATERIAL AND METHOD

Psychopathological symptoms, cognitive functioning and formal thought disorder were evaluated in 32 hospitalized adolescent patients with schizophrenia spectrum diagnosis at the beginning of risperidone treatment and after clinical improvement and compared to the results of matched healthy control group.

RESULTS

Risperidone treatment was associated with reduction of symptom severity and moderate improvement of formal thought disorder and some aspects of executive functions. Working memory and verbal fluency were not improved. There were few correlations between psychopathological symptoms and results of cognitive tests, mainly between negative symptoms and executive functions.

DISCUSSION

In early-onset schizophrenia spectrum disorders atypical antipsychotic treatment is associated with alleviation of symptoms and only selective and moderate cognitive and communication improvement.

Maintenance treatment with antipsychotic drugs for schizophrenia

BACKGROUND

The symptoms and signs of schizophrenia have been firmly linked to high levels of dopamine in specific areas of the brain (limbic system). Antipsychotic drugs block the transmission of dopamine in the brain and reduce the acute symptoms of the disorder. This review examined whether antipsychotic drugs are also effective for relapse prevention.

OBJECTIVES

To review the effects of maintaining antipsychotic drugs for people with schizophrenia compared to withdrawing these agents.

SEARCH METHODS

We searched the Cochrane Schizophrenia Group's Specialised Register (November 2008), with additional searches of MEDLINE, EMBASE and clinicaltrials.gov (June 2011).

SELECTION CRITERIA

We included all randomised trials comparing maintenance treatment with antipsychotic drugs and placebo for people with schizophrenia or schizophrenia-like psychoses.

DATA COLLECTION AND ANALYSIS

We extracted data independently. For dichotomous data we calculated relative risks (RR) and their 95% confidence intervals (CI) on an intention-to-treat basis based on a random-effects model. For continuous data, we calculated mean differences (MD) or standardised mean differences (SMD) again based on a random-effects model.

MAIN RESULTS

The review currently includes 65 randomised controlled trials (RCT(s)) and 6493 participants comparing antipsychotic medication with placebo. The trials were published from 1959 to 2011 and their size ranged between 14 and 420 participants. In many studies the methods of randomisation, allocation and blinding were poorly reported. Although this and other potential sources of bias limited the overall quality, the efficacy of antipsychotic drugs for maintenance treatment in schizophrenia was clear. Antipsychotic drugs were significantly more effective than placebo in preventing relapse at seven to 12 months (primary outcome; drug 27%, placebo 64%, 24 RCT(s), n=2669, RR 0.40 CI 0.33 to 0.49, number needed to treat for an additional beneficial outcome (NNTB 3 CI 2 to 3). Hospitalisation was also reduced, however, the baseline risk was lower (drug 10%, placebo 26%, 16 RCT(s), n=2090, RR 0.38 CI 0.27 to 0.55, NNT 5 CI 4 to 9). More participants in the placebo group than in the antipsychotic drug group left the studies early due to any reason (at 7-12 months: drug 38%, placebo 66%, 18 RCT(s), n=2420, RR 0.55 CI 0.46 to 0.66, NNTB 4 CI 3 to 5) and due to inefficacy of treatment (at 7-12 months: drug 20%, placebo 50%, 18 RCT(s), n=2420, RR 0.36 CI 0.28 to 0.45, NNTB 3 CI 2 to 4). Quality of life was better in drug-treated participants (3 RCT(s), n=527, SMD -0.62 CI -1.15 to -0.09). Conversely, antipsychotic drugs as a group and irrespective of duration, were associated with more participants experiencing movement disorders (e.g. at least one movement disorder: drug 16%, placebo 9%, 22 RCT(s), n=3411, RR 1.55 CI 1.25 to 1.93, NNTH 25 CI 13 to 100), sedation (drug 13%, placebo 9%, 10 RCT(s), n=146, RR 1.50 CI 1.22 to 1.84, number needed to treat for an additional harmful outcome (NNTH) not significant) and weight gain (drug 10%, placebo 6%, 10 RCT(s), n=321, RR 2.07 CI 1.31 to 3.25, NNTH 20 CI 14 to 33). The results of the primary outcome were robust in a number of subgroup, meta-regression and sensitivity analyses, the main exception being that the drug-placebo difference in longer trials was smaller than in shorter trials.

AUTHORS' CONCLUSIONS

The results clearly demonstrate the superiority of antipsychotic drugs compared to placebo in preventing relapse. This effect must be weighed against the side effects of antipsychotic drugs. Future studies should focus on outcomes of social participation and clarify the long-term morbidity and mortality associated with these drugs.

Thought disorder in offspring of schizophrenic parents: findings from the New York High-Risk Project

The goal of the present analyses was to examine the hypothesis that mild forms of thought disorder (TD) may serve as an indicator of genetic liability for schizophrenia. A subset of 232 subjects drawn from the New York High-Risk Project was used to compare individuals at high risk for schizophrenia (ie, offspring of parents with schizophrenia; n = 63) with 2 groups of individuals at low risk for schizophrenia (ie, offspring of parents with affective disorder [n = 52] and offspring of psychiatrically normal parents [n = 117]). Subjects were administered the Rorschach Inkblot Test, and their responses were assessed according to the Thought Disorder Index (TDI). The high-risk offspring displayed significantly more TD than the other 2 groups, as shown by significantly higher TDI scores. Moreover, they had more deviant verbalizations, according to their significantly higher scores on a composite Idiosyncratic Verbalizations score. As expected, the offspring who developed psychosis produced more TD in adolescence than those who did not develop psychosis. In the sample as a whole, TD scores during late adolescence/early adulthood were positively associated with schizotypal features during mid-adulthood. These findings support the assertion that the presence of TD serves as an endophenotypic marker of a schizophrenia diathesis.

The Genetic Basis of Thought Disorder and Language and Communication Disturbances in Schizophrenia

Thought disorder as well as language and communication disturbances are associated with schizophrenia and are over-represented in clinically unaffected relatives of schizophrenics. All three kinds of dysfunction involve some element of deviant verbalizations, most notably, semantic anomalies. Of particular importance, thought disorder characterized primarily by deviant verbalizations has a higher recurrence in relatives of schizophrenic patients than schizophrenia itself. These findings suggest that deviant verbalizations may be more penetrant expressions of schizophrenia susceptibility genes than schizophrenia. This paper reviews the evidence documenting the presence of thought, language and communication disorders in schizophrenic patients and in their first-degree relatives. This familial aggregation potentially implicates genetic factors in the etiology of thought disorder, language anomalies, and communication disturbances in schizophrenia families. We also present two examples of ways in which thought, language and communication disorders can enrich genetic studies, including those involving schizophrenia.

Brain/behavior Asymmetry in Schizophrenia: A MEG Study of Cross-modal Semantic Priming

Semantic priming has long been used to investigate how concepts and ideas are related at the level of language, and has become a convenient tool for assessing conceptual and semantic dysfunction in cognitive disorders, including schizophrenia. The study of semantic priming in schizophrenia has led to diverse results: enhanced priming, reduced priming, and priming equivalent to that found in nonpsychiatric comparison groups. A number of hypotheses have been proposed to explain some of the observed deficits in schizophrenia patients. For example, difficulties in word recognition may be due to hyperactivation of too many lexical representations or to a failure to inhibit lexical competitors. One way to distinguish between these possible explanations is to move beyond reliance on behavior alone and to examine the neural processes involved in lexical recognition. Here we present a magnetoencephalographic study of semantic priming in schizophrenia. Importantly, schizophrenia patients and healthy controls did not differ in performance on a priming task. We show that normal behavioral performance can occur in a context of aberrant neural responses. These findings suggest that normal behavioral responses in schizophrenia can be achieved through neural mechanisms that differ from those seen in the psychiatrically well brain.

The power of linkage analysis of a disease-related endophenotype using asymmetrically ascertained sib pairs

A linkage study of a qualitative disease endophenotype in a sample of sib pairs, consisting of one disease affected proband and one sibling is considered. The linkage statistic compares marker allele sharing with the proband in siblings with an abnormal endophenotype to siblings with the normal endophenotype. Expressions for the distribution of this linkage statistic, in terms of the recombination fraction are derived and (1) the genetic parameter values (allele frequency and endophenotype and disease penetrance) and (2) the abnormal endophenotype rates in the population and in classes of relatives of disease affected probands. It is then shown that when either the disease or the abnormal endophenotype has additive penetrance, the expressions simplify to a monotonic function of the difference between abnormal endophenotype rates in siblings and in the population. Thought disorder is considered as a putative schizophrenia endophenotype. Forty sets of genetic parameter values that correspond to the known prevalence values for thought disorder in schizophrenic patients, siblings of schizophrenics and the general population are evaluated. For these genetic parameter values, numerical results show that the test statistic has>70% power (α = 0.0001) in general with a sample of 200 or more proband-sibling pairs to detect the linkage between a marker (θ = 0.01), and a locus pleiotropic for schizophrenia and thought disorder.

Factor structure of the Greek translation of the Scale for the Assessment of Thought, Language and Communication

OBJECTIVE

The Scale for the Assessment of Thought, Language and Communication (TLC) is a widely used instrument for the assessment of formal thought disorder. TLC disorders were initially conceptualized as having only two underlying dimensions, a negative and a positive one. But studies of the factorial structure of the TLC have not provided confirmation for the positive-versus-negative distinction. The aim of the present study was to assess the factorial structure of the Greek translation of the TLC.

METHOD

Subjects were 103 patients (69 male, 34 female) with psychotic disorders randomly recruited from both inpatient and outpatient facilities. The TLC was assessed by two raters based on a 20 min clinical interview.

RESULTS

Principal component analysis with varimax rotation yielded a three-factor structure; the three factors consisted off items reflecting (i) disorganization of speech; (ii) peculiarities of speech; and (iii) verbosity. The disorganization factor could be further divided into two dimensions reflecting disturbances in the flow of ideas and in the structure of speech.

CONCLUSION

The investigation of the factorial structure of the Greek translation of the TLC scale found no support for the positive-versus-negative distinction of TLC disorders. Three factors (disorganization, speech peculiarities, and verbal productivity) were found to underlie the variance of the scale.

Quantifying incoherence in speech: an automated methodology and novel application to schizophrenia

Incoherent discourse, with a disjointed flow of ideas, is a cardinal symptom in several psychiatric and neurological conditions. However, measuring incoherence has often been complex and subjective. We sought to validate an objective, intrinsically reliable, computational approach to quantifying speech incoherence. Patients with schizophrenia and healthy control volunteers were administered a variety of language tasks. The speech generated was transcribed and the coherence computed using Latent Semantic Analysis (LSA). The discourse was also analyzed with a standard clinical measure of thought disorder. In word association and generation tasks LSA derived coherence scores were sensitive to differences between patients and controls, and correlated with clinical measures of thought disorder. In speech samples LSA could be used to localize where in sentence production incoherence occurs, predict levels of incoherence as well as whether discourse "belonged" to a patient or control. In conclusion, LSA can be used to assay disordered language production so as to both complement human clinical ratings as well as experimentally parse this incoherence in a theory-driven manner.

Neuroanatomical correlates of formal thought disorder in schizophrenia

INTRODUCTION

We attempted to extend findings of a relationship between formal thought disorder and left superior temporal gyrus (STG) volume in schizophrenia by examining two indices of formal thought disorder.

METHODS

Three brain regions of interest were selected from magnetic resonance imaging slices in 15 young, right-handed, male schizophrenia patients: the STG, the anterior hippocampus, and the amygdala. Thought disorder was assessed using the Bizarre-Idiosyncratic Thinking (BIZ) scale, a sensitive measure of formal thought disorder based on responses to a standard set of stimuli, and the BPRS Conceptual Disorganization item, a global rating based on a clinical interview.

RESULTS

BIZ ratings of thought disorder were significantly correlated with the left STG volume (Spearman r = -.73) and with the right STG volume (Spearman r = -.58). BIZ ratings were not significantly correlated with either the left or right anterior hippocampus or amygdala volumes. The BPRS Conceptual Disorganisation rating was not significantly related to the STG, anterior hippocampus, or amygdala volumes.

CONCLUSIONS

This study confirms the previously reported association between the left STG and formal thought disorder, and suggests that detection of this relationship may be facilitated by use of highly sensitive formal thought disorder assessments.

Thought and Language Index: an instrument for assessing thought and language in schizophrenia

BACKGROUND

Subtle formal thought disorders are difficult to quantify. Their relationship to florid thought disorder is unknown.

AIMS

To assess the interrater reliability, sensitivity and factor structure of a new assessment instrument, the Thought and Language Index (TLI), and to determine if minor aberrations detectable in the speech of healthy individuals are related to the more severe formal thought disorders characteristic of schizophrenia.

METHOD

Interrater reliability was evaluated by determining the intraclass correlation for the ratings by five assessors. Factor analysis of the TLI scores of 87 patients was performed, and TLI scores in matched patients and controls were compared.

RESULTS

The intraclass correlation was good for individual TLI items, and excellent for sub-scale scores. Factor analysis identified three groups of approximately orthogonal disorders. Mild speech aberrations were observed in healthy participants and in patients with schizophrenia. The prevalence of mild aberrations was correlated with the prevalence of definite formal thought disorders.

CONCLUSIONS

The TLI is reliable and capable of detecting subtle disorders. Some mild aberrations occurring in the speech of healthy individuals appear to be attenuated forms of the florid disorders characteristic of schizophrenia.

Assessing disturbed thinking and cognition using the Ego Impairment Index in older schizophrenia patients: paranoid vs. nonparanoid distinction

OBJECTIVE

We compared thought-disturbance via the Rorschach-derived Ego Impairment Index (EII) between DSM-IV paranoid vs. nonparanoid (undifferentiated and disorganized) subtypes of older schizophrenia patients.

METHODS

44 DSM-IV medically stable outpatients with schizophrenia (27 paranoid, 17 nonparanoid) and 45 normal comparison participants aged 45-100 years were assessed using the EII, a Rorschach-derived cognitive-based measure of disturbed thinking. Group differences on the EII and the relation of this measure to key demographic and clinical variables were examined.

RESULTS

Nonparanoid schizophrenia patients demonstrated significantly greater impairment on the EII than their paranoid counterparts. The EII performance of paranoid patients was similar to normal comparison participants. Furthermore, the paranoid patients displayed better premorbid intellectual functioning, less negative symptoms, and better global cognitive performance than nonparanoid patients. Finally, greater impairment on the EII was correlated with poor performance on a global measure of cognitive ability.

CONCLUSIONS

The present findings substantiate previous work suggesting that nonparanoid patients have a form of the illness characterized by worse premorbid functioning and greater disturbed thinking and cognition than their paranoid counterparts.

The effects of psychoactive drugs and neuroleptics on language in normal subjects and schizophrenic patients: a review

The aim of this survey is to present an overview of research into psychopharmacology as regards the effects of different psychoactive drugs and neuroleptics (NL) on language in normal subjects and schizophrenic patients. Eighteen studies that have investigated the effects of different drugs (alcohol, amphetamines, secobarbital, L-dopa, psilocybin, ketamine, fenfluramine) and neuroleptics (conventional and atypical) on language are reviewed. There are no studies concerning the effects of neuroleptics on language in healthy subjects. The results of the effects of other molecules indicate that language production can be increased (alcohol, amphetamine, secobarbital), rendered more complex (d-amphetamine), more focused (L-dopa) or more unfocused (psilocybin) and clearly impaired (ketamine). For schizophrenic patients, most studies show that conventional neuroleptic treatments, at a therapeutic dosage and in acute or chronic mode, reduce language disorders at all levels (clinic, linguistic, psycholinguistic). In conjunction with other molecules, the classical NL, when administered at a moderate dosage and in chronic mode, modify language in schizophrenia, either by improving the verbal flow and reducing pauses and positive thought disorder (NL + amphetamine) or by inducing an impairment in the language measurements (NL + fenfluramine). Clinical, methodological and theoretical considerations of results are debated in the framework of schizophrenic language disorders.

Thought disorder in adolescent-onset schizophrenia

The nature of the thinking disturbances found in adolescent-onset psychotic conditions is not as well-characterized as the thought disorders found in adult psychotic patients. We used the Thought Disorder Index to examine whether schizophrenic patients in whom psychotic symptoms appear in adolescence show the same characteristic features of thought disorder as do adult schizophrenics. Quantitative and qualitative features of thought disorder were assessed in psychiatric inpatients with adolescent-onset schizophrenia, psychotic depression, and nonpsychotic conditions compared with normal control adolescents. Elevated thought disorder occurred in all groups of adolescents hospitalized for an acute episode of psychiatric illness. The magnitude of the elevation and the frequency of occurrence of disordered thinking were greatest in the psychotic adolescents. The qualitative features of the thought disturbances found in the schizophrenic adolescents were distinct from those observed in adolescents with psychotic depression. The thinking of the schizophrenic adolescents resembled that of adult schizophrenics. In both conditions thought disorder is characterized by idiosyncratic word usage, illogical reasoning, perceptual confusion, loss of realistic attunement to the task, and loosely related ideas.

Sustained attention and positive formal thought disorder in schizophrenia

Deficits in sustained attention and formal thought disorder (FTD) are two characteristics of schizophrenia that might be expressions of a common pathology. This study examined whether a measure of enduring (post-treatment, stabilized) deficits in sustained attention, the Continuous Performance Test (CPT) could predict FTD. In addition, a comparison was made of CPT performance between subjects with schizophrenia (n = 41) and healthy controls (n = 28). Results replicated previous findings of significantly poorer performance by individuals with schizophrenia compared to normal controls. Within the schizophrenia group, significant correlations were found between FTD and CPT measures. In order to assess predictability of FTD, a hierarchical multiple regression analysis was used. CPT errors and gender both significantly predicted FTD. The most robust prediction was of residual FTD (post-treatment, stabilized) by CPT commission errors. These results lend support to the proposition that a subsyndrome within schizophrenia exists that is characterized by deficits in sustained attention and positive formal thought disorder. Furthermore, this subsyndrome might be more common in males than females.

On the assessment of thought disorder from the Rorschach

While the Rorschach has been proven useful in assessing severity of thought disorder, the assessment of extent of thought disorder evidenced in any one protocol is made subjectively, that is, on the basis of clinical impression. Objective methods for assessing thought disorder on the Rorschach were reviewed and evaluated. Problems in the development of such methods which have limited their psychometric efficiency were discussed, and possible solutions of these problems were suggested. Since severity of thought disorder relates to prognosis and treatment, the further exploration of more effective ways of assessing thought disorder by the Rorschach seems warranted.

Methylphenidate increases thought disorder in recent onset schizophrenics, but not in normal controls

The effects of apomorphine and methylphenidate on thought disorder, as measured by the Thought Disorder Index, in schizophrenic patients and in normal controls were evaluated. Methylphenidate, but not apomorphine, increased thought disorder in patients. Neither drug significantly increased thought disorder in controls.

Relations between attentional deficits and clinical symptoms in schizophrenic outpatients

Information-processing impairments have been suggested to be at the core of the cognitive deficits observed in schizophrenia and may represent preclinical markers of genetic vulnerability to the illness. Of particular importance in information-processing research have been measures such as the Continuous Performance Test (CPT) and the Partial Report Span of Apprehension (SPAN) that place high momentary loads on processing resources. The relationships between the two cognitive measures and between the two measures and clinical symptoms were examined in 50 patients with either DSM-III-R schizophrenia or schizoaffective disorder. The information-processing measures were modestly correlated with each other and with an estimate of verbal, but not nonverbal IQ. The SPAN was correlated with negative symptoms and the CPT with formal thought disorder. These results provide some evidence of convergent validity but also suggest that constructs other than high momentary processing load are implicated in their sensitivity to schizophrenia.

Language comprehension in schizophrenics and their brothers

Disturbances in language functioning may be associated with familial vulnerability to schizophrenia. Language comprehension, measured by the Luria-Nebraska Relational Concepts Factor Scale, was evaluated in 36 schizophrenic probands and their nonschizophrenic adult brothers (n = 41), and in 18 normal controls. Language comprehension performance was a function of psychiatric diagnosis in the brothers. Brothers who met criteria for schizophrenia-spectrum disorders showed significantly reduced language performance compared with unaffected brothers and normal controls. Moreover, abnormal language performance was exhibited by significantly more probands and spectrum-disordered brothers than by the normal controls and the brothers without schizophrenia-spectrum disorders. Finally, language performance was not significantly different for 31 pairs of schizophrenic probands and their brothers. Impaired language comprehension appeared comparatively specific in this sample of relatives, as groups were not significantly different on measures of nonlinguistic concept formation (Wisconsin Card Sorting Test) and general intellectual functioning (WAIS-R Information and Block design). Results suggest that impaired language comprehension is associated with familial vulnerability to schizophrenia, and that this disturbance may be most severe in relatives diagnosed with schizophrenia-spectrum disorders.

Schizophrenics and social judgement. Why do schizophrenics get it wrong?

Videotaped social interactions were shown to a population of schizophrenics and controls who were asked to comment on the emotional state of the principal protagonist. Their free responses were subjected to a content analysis to examine which of three possible explanations of known schizophrenic inaccuracies on this task were responsible: formal thought disorder, selective avoidance of psychological factors, or perceptual/attentional deficits. Neither selective avoidance nor marked thought disorder were found to explain these errors. The schizophrenics as a group rated much the same, irrespective of clinical profile. Their judgements of personality were less clear-cut than the controls.

Formal thought disorder in schizophrenia: a factor analytic study

The Thought, Language and Communication Scale (TLC) was studied in a sample composed of 115 DSM-III-R schizophrenic patients admitted to an acute inpatient unit. A principal component analysis with varimax rotation was performed to explore the possibility of the existence of syndromes within the formal thought disturbances. Seven factors were found to have eigen values greater than 1 and five showed appropriate internal consistency. The first factor, or disorganization factor, was close to the Scale for the Assessment of Positive Symptoms (SAPS) formal thought disturbance subscale. The second, or negative factor (perseveration, poverty of speech and content), was moderately correlated with poor premorbid functioning and poor response to neuroleptic treatment. The third and fourth factors were, respectively, formed by stilted speech plus word approximations, and neologisms plus clanging. The fifth factor (distractibility and blocking), as well as the first two factors, were correlated to the Scale for the Assessment of Negative Symptoms (SANS) attention subscale.

Communication deficits and formal thought disorder in schizophrenic children

This study examined 31 schizophrenic children to determine if they used discourse devices that make speech coherence differently from sex and mental age matched normal children. It also investigated whether the discourse deficits of the schizophrenic children were related to clinical measures of formal thought disorder. Using Halliday and Hassan's analysis of cohesion, the authors found that schizophrenic children underutilize some discourse devices and overutilize others. Several of their discourse deficits were similar to those described in schizophrenic adults. The schizophrenic children, however, also had additional discourse deficits, which probably reflect developmental delays. The authors also demonstrated that the schizophrenic children with loose associations had different discourse deficits and discourse/IQ correlates than schizophrenic children without loose associations. The schizophrenic children receiving neuroleptic medication had lower loose associations scores than the unmedicated subjects. The authors discuss the possible confounding effect of medication and loose associations, as well as the developmental, cognitive, and clinical implications of the study's findings.

Formal thought disorder in childhood onset schizophrenia and schizotypal personality disorder

The Kiddie Formal Thought Disorder Rating Scale (K-FTDS) was examined in a sample of 29 schizophrenic, 10 schizotypal, and 54 normal children, aged 5-12.5 yrs. The schizophrenic and schizotypal children had significantly more illogical thinking and loose associations than the normal children. There were no significant differences between the illogical thinking and loose associations ratings of the schizophrenic and schizotypal children. Young schizophrenic, schizotypal, and normal children had more illogical thinking and loose associations than older children in their respective groups. The diagnostic, developmental, and cognitive implications of the study's results are discussed.

Syndromes of chronic schizophrenia

Confirmation is reported of an earlier finding that the symptoms of patients with chronic schizophrenia segregate into three syndromes: psychomotor poverty (poverty of speech, flatness of affect, decreased spontaneous movement); disorganisation (disorders of the form of thought, inappropriate affect); and reality distortion (delusions and hallucinations).

Social competence in schizoaffective disorder, bipolar disorder, and negative and non-negative schizophrenia

Social skill and role functioning were assessed in matched groups of patients with DSM-III-R schizoaffective disorder, bipolar disorder, and schizophrenia. Schizophrenics were categorized as negative syndrome or non-negative on the basis of the SANS. The negative schizophrenics were significantly more impaired on almost every measure of social functioning. The other three groups were not consistently different from one another. The results suggest that when patients are comparable on dimensions such as duration and severity of illness, schizoaffectives do not occupy an intermediate position between schizophrenics without negative syndrome and bipolar patients. Rather, the three groups exhibit similar degrees of social disability. In contrast, negative syndrome schizophrenics were more impaired even when they were similar in chronicity and severity.