Awareness and unawareness of thought disorder

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.

Assessing the dimensionality of scores derived from the Revised Formal Thought Disorder Self-Report Scale in schizotypy

The current work explored the dimensionality and convergent validity of responses to Barrera et al.'s (2015) 29-item Formal Thought Disorder-Self Scale (FTD-SS) obtained in two non-clinical samples. Exploratory factor analyses were conducted in Sample 1 (n = 324), yielding evidence of three correlated factors, although simple structure was not achieved until nine items were removed. Support for the correlated three factors model of responses to the revised 20-item scale (FTD-SS-R) was replicated when a confirmatory factor analysis was conducted in Sample 2 (n = 610). Finally, convergent associations were found between FTD-SS-R scores and scores from other schizotypy measures across both samples, though these measures only explained half of the variance in FTD-SS-R scores. Additional research is needed to evaluate the appropriateness of the items and incremental validity of the scale in non-clinical samples.

Disorganisation, thought disorder and socio-cognitive functioning in schizophrenia spectrum disorders

BACKGROUND

Poor social cognition is prevalent in schizophrenia spectrum disorders. Some authors argue that these effects are symptom-specific and that socio-cognitive difficulties (e.g. theory of mind) are strongly associated with thought disorder and symptoms of disorganisation.AimsThe current review tests the strength of this association.

METHOD

We meta-analysed studies published between 1980 and 2016 that tested the association between social cognition and these symptoms in schizophrenia spectrum disorders.

RESULTS

Our search (PsycINFO, MEDLINE and Web of Science) identified 123 studies (N = 9107). Overall effect size as r = -0.313, indicating a moderate association between symptoms and social cognition. Subanalyses yielded a moderate association between symptoms and theory of mind (r = -0.349) and emotion recognition (r = -0.334), but smaller effect sizes for social perception (r = -0.188), emotion regulation (r = -0.169) and attributional biases (r = -0.143).

CONCLUSIONS

The association is interpreted within models of communication that highlight the importance of mentalisation and processing of partner-specific cues in conversational alignment and grounding.Declaration of interestsNone.

'No man is an island'. Testing the specific role of social isolation in formal thought disorder

Recent work has focused on the role of the environment in psychosis with emerging evidence that specific psychotic experiences are associated with specific types of adversity. One risk factor that has been often associated with psychosis is social isolation, with studies identifying isolation as an important feature of prodromal psychosis and others reporting that social networks of psychotic patients are smaller and less dense than those of healthy individuals. In the present study, we tested a prediction that social isolation would be specifically associated with formal thought disorder. 80 patients diagnosed with psychosis-spectrum disorder and 30 healthy participants were assessed for formal thought disorder with speech samples acquired during an interview that promoted personal disclosure and an interview targeting everyday topics. Social isolation was significantly associated with formal thought disorder in the neutral interview and in the salient interview, even when controlling for comorbid hallucinations, delusions and suspiciousness. Hallucinations, delusions and suspiciousness were not associated with social isolation when formal thought disorder was controlled for. Formal thought disorder is robustly and specifically associated with social isolation. Social cognitive mechanisms and processes are discussed which may explain this relationship as well as implications for clinical practice and future research.

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.

Criterion validity of the financial skills subscale of the direct assessment of functional status scale

Among the severely mentally ill, some individuals with schizophrenia or schizoaffective disorder can manage their finances independently, while others depend upon a court-appointed guardian or a representative payee. The present study examined the criterion validity of the financial skills subscale of the Direct Assessment of Functional Status (DAFS) scale in classifying those who manage their finances independently from those who do not. Scores on the financial skills subscale of the DAFS scale of 25 severely mentally ill outpatients without a guardian/payee were compared to scores of 24 severely mentally ill outpatients with a guardian/payee; 25 non-mentally ill participants served as controls. Logistic regression analyses, Bayesian statistics, and Receiver Operating Characteristic analyses revealed moderate classification accuracy in a sample with mild cognitive impairment. These analyses were also conducted on Mini-Mental State Examination (MMSE) scores and revealed generally lower accuracy than the DAFS financial skills subscale. The DAFS financial skills subscale can inform the clinician's opinion about the financial capacity of the severely mentally ill.

Correlates of delusion-like experiences in a non-psychotic community sample

OBJECTIVE

Several large population-based studies have reported that otherwise-well individuals endorse items related to delusion-like experiences. The aim of the present study was to examine selected correlates of delusion-like experiences in a sample of non-psychotic individuals.

METHOD

Subjects (n=310) were screened with the Diagnostic Interview for Psychosis in order to exclude psychotic disorders. Delusion-like experiences were assessed with the Peters Delusional Inventory (PDI). Non-parametric statistics were used to assess the relationship between total PDI score and a range of demographic (age, sex, migrant status, paternal age), physical (minor physical anomalies) symptom-related variables (hallucinations, awareness of thought disorder) and family history of mental illness.

RESULTS

The median (range) PDI score was 4 (0-26), while one-third of the subjects endorsed seven or more items. The presence of a family history of any psychiatric condition was significantly correlated with a higher PDI score. PDI score was significantly positively correlated with endorsement of hallucinations and awareness of thought disorder. PDI was not significantly associated with sex, family history of schizophrenia, paternal age, migrant status nor scores related to minor physical anomalies. There was a trend level association between younger age and higher PDI score.

CONCLUSION

Delusion-like experiences are relatively common in non-psychotic individuals. The association with a family history of mental disorders provides clues to the mechanisms underlying the profile of delusion-like experience.

Effect of thought disorders on quality of life in patients with schizophrenia

OBJECTIVE

The aim of the present study was to investigate the impact of thought disorder on quality of life in patients with schizophrenia.

METHODS

Seventy two patients with schizophrenia and 46 healthy subjects were included in the study. World Health Organization Quality of Life Instrument Short Forum (WHOQOL-BREF) was given to patients and healthy subjects to assess quality of life. Thought and Language Index (TLI) for thought disorders, Positive and Negative Syndrome Scale (PANNS) for symptom and Calgary Depression Scale (CDS) for depressive symptoms were administered to the patients.

RESULTS

The comparison of quality of life between patients and healthy subjects showed a significant difference except environmental domain. There were no significant correlations between thought disorder and quality of life in patients with schizophrenia.

CONCLUSION

The present study revealed that quality of life was lower in patients with schizophrenia compared to healthy subjects. There was no relation between thought disorders and quality of life in schizophrenia. Patients with schizophrenia were aware of their quality of life perception.

Two new scales of formal thought disorder in schizophrenia

Information provided by patients and respective carers may help to understand formal thought disorder (FTD) in schizophrenia. Two scales, one for patients (FTD-patient) and one for carers (FTD-carer), were constructed to assess pragmatics, cognitive, paralinguistic, and non-verbal aspects of communication. In the first scale the patients themselves assess their verbal communication; in the second scale the carer assesses the speech of the respective patient. Both scales exhibited internal reliability and evidence of good test-retest reliability. Higher total scores on both scales (FTD-patient and FTD-carer) were significantly associated with positive FTD, but not with negative FTD. Principal component analysis of the scales yielded a multidimensional structure. It is suggested that FTD in schizophrenia may be associated with a range of deficits (e.g. pragmatics, lexical activation, working memory, sustained attention). These scales, in conjunction with the clinician's assessment, can provide a more comprehensive picture of FTD in schizophrenia, revealing its dimensions and making it possible to establish associations between symptoms of FTD and neuropsychological, neurophysiologic, and neuroimaging data. In addition, they provide service users' and carers' perspectives for the assessment of communication in schizophrenia.

Work-related subjective experiences among community residents with schizophrenia or schizoaffective disorder

OBJECTIVE

To develop a self-report scale of subjective experiences of illness perceived to impact on employment functioning, as an alternative to a diagnostic perspective, for anticipating the vocational assistance needs of people with schizophrenia or schizoaffective disorders.

METHOD

A repeated measures pilot study (n(1) = 26, n(2) = 21) of community residents with schizophrenia identified a set of work-related subjective experiences perceived to impact on employment functioning. Items with the best psychometric properties were applied in a 12 month longitudinal survey of urban residents with schizophrenia or schizoaffective disorder (n(1) = 104; n(2) = 94; n(3) = 94).

RESULTS

Construct validity, factor structure, responsiveness, internal consistency, stability, and criterion validity investigations produced favourable results. Work-related subjective experiences provide information about the intersection of the person, the disorder, and expectations of employment functioning, which suggest new opportunities for vocational professionals to explore and discuss individual assistance needs.

CONCLUSION

Further psychometric investigations of test-retest reliability, discriminant and predictive validity, and research applications in supported employment and vocational rehabilitation, are recommended. Subject to adequate psychometric properties, the new measure promises to facilitate exploring: individuals' specific subjective experiences; how each is perceived to contribute to employment restrictions; and the corresponding implications for specialized treatment, vocational interventions and workplace accommodations.