scholarly journals Schizophrenia Phenomenology Revisited: Positive and Negative Symptoms are Strongly Related Reflective Manifestations of an Underlying Single Trait Indicating Overall Severity of Schizophrenia

2019 ◽  
Author(s):  
Abbas Almulla ◽  
Hussein Al-Hakeim ◽  
Michael Maes
Keyword(s):  
Convergent Validity ◽  
Negative Symptoms ◽  
Discriminant Validity ◽  
Psychomotor Retardation ◽  
Future Research ◽  
Stable Phase ◽  
Latent Vector ◽  
Thought Disorders ◽  
Symptom Domains ◽  
Positive And Negative Symptoms

Schizophrenia comprises various symptom domains, including positive and negative symptoms. Machine learning showed that a) negative symptoms are significantly interrelated with PHEM (psychosis, hostility, excitation, and mannerism) symptoms, formal thought disorders (FTD) and psychomotor retardation (PMR); and b) stable phase schizophrenia comprises two distinct classes, namely Major Neuro-Cognitive Psychosis (MNP, largely overlapping with deficit schizophrenia) and Simple NP (SNP). In this study, we recruited 120 MNP patients and 54 healthy subjects and measured the above-mentioned symptom domains. In MNP, there were significant associations between negative and PHEM symptoms, FTD and PMR. A single latent trait, which is essentially unidimensional, underlies these key domains of schizophrenia and MNP and additionally shows excellent internal consistency reliability, convergent validity, and predictive relevance. Confirmatory Tedrad Analysis indicates that this latent vector fits a reflective model. The lack of discriminant validity shows that PHEM and negative symptoms greatly overlap and probably measure the same construct. Soft Independent Modeling of Class Analogy (SIMCA) shows that MNP (diagnosis based on negative symptoms) is better modeled using PHEM symptoms, FTD, and PMR than negative symptoms. In conclusion, in stable phase MNP, a restricted sample of the schizophrenia population, negative and PHEM symptoms, FTD and PMR belong to one underlying latent vector reflecting overall severity of schizophrenia (OSOS). The bi-dimensional concept of “positive” and “negative” symptoms cannot be validated and, therefore, future research in stable phase schizophrenia should consider that the latent phenomenon OSOS as well as its 8 reflective manifestations are the key factors of schizophrenia phenomenology.

Schizophrenia phenomenology revisited: positive and negative symptoms are strongly related reflective manifestations of an underlying single trait indicating overall severity of schizophrenia

CNS Spectrums ◽  
2020 ◽  
pp. 1-10 ◽  
Author(s):  
Abbas F. Almulla ◽  
Hussein K. Al-Hakeim ◽  
Michael Maes
Keyword(s):  
Convergent Validity ◽  
Negative Symptoms ◽  
Discriminant Validity ◽  
Psychomotor Retardation ◽  
Future Research ◽  
Stable Phase ◽  
Deficit Schizophrenia ◽  
Latent Vector ◽  
Thought Disorders ◽  
Positive And Negative Symptoms

Abstract Background. To examine whether negative symptoms, psychosis, hostility, excitation, and mannerism (PHEM symptoms), formal thought disorders (FTD) and psychomotor retardation (PMR) are interrelated phenomena in major neurocognitive psychosis (MNP) or deficit schizophrenia and whether those domains belong to an underlying latent vector reflecting general psychopathology. Methods. In this study, we recruited 120 patients with MNP or deficit schizophrenia and 54 healthy subjects and measured the above-mentioned symptom domains. Results. In MNP, there were significant associations between negative and PHEM symptoms, FTD and PMR. A single latent trait, which is essentially unidimensional, underlies these key domains of schizophrenia and MNP and additionally shows excellent internal consistency reliability, convergent validity, and predictive relevance. Confirmatory Tedrad Analysis indicates that this latent vector fits a reflective model. The lack of discriminant validity shows that positive (and PHEM or psychotic) and negative symptoms greatly overlap and probably measure the same latent construct. Soft independent modeling of class analogy (SIMCA) shows that MNP (diagnosis based on negative symptoms) is better modeled using PHEM symptoms, FTD, and PMR than negative symptoms. Conclusions. In stable phase MNP, which is a restricted sample of the schizophrenia population, negative and PHEM symptoms, FTD and PMR belong to one underlying latent vector reflecting overall severity of schizophrenia (OSOS). The bi-dimensional concept of “positive” and “negative” symptoms cannot be validated and, therefore, future research in stable phase schizophrenia should consider that the latent phenomenon OSOS as well as its reflective manifestations are the key factors of schizophrenia phenomenology.

Schizophrenia phenomenology revisited: positive and negative symptoms are strongly related reflective manifestations of an underlying single trait indicating overall severity of schizophrenia

2019 ◽  
Author(s):  
Abbas F. Almulla ◽  
Hussein Kadhem Al-Hakeim ◽  
Michael Maes
Keyword(s):  
Convergent Validity ◽  
Negative Symptoms ◽  
Supervised Machine Learning ◽  
Machine Learning Techniques ◽  
Stable Phase ◽  
Type I ◽  
Latent Vector ◽  
Thought Disorders ◽  
Symptom Domains ◽  
Positive And Negative Symptoms

Schizophrenia comprises various symptom domains the two most important being positive <br>and negative symptoms. Nevertheless, using (un)supervised machine learning techniques it was <br>shown that a) negative symptoms are significantly interrelated with PHEM (psychosis, hostility, <br>excitation, and mannerism) symptoms, formal thought disorders (FTD) and psychomotor <br>retardation (PMR); and b) stable phase schizophrenia comprises two distinct classes, namely Major <br>Neuro-Cognitive Psychosis (MNP, largely overlapping with deficit schizophrenia) and Simple <br>NP (SNP). In this study, we recruited 120 MNP patients and 54 healthy subjects and measured the <br>above-mentioned symptom domains. In MNP, there were significant associations between <br>negative and PHEM symptoms, FTD and PMR. A single latent trait, which is essentially <br>unidimensional, underlies these key domains of schizophrenia and additionally shows excellent <br>internal consistency reliability, convergent validity, and predictive relevance. Confirmatory Tedrad <br>Analysis indicates that this latent vector fits a reflective model. Soft Independent Modeling of <br>Class Analogy (SIMCA) shows that MNP (diagnosis based on negative symptoms) is better <br>modeled with PHEM symptoms, FTD and PMR than with negative symptoms. In conclusion, in <br>MNP, a restricted sample of the schizophrenia population, negative and PHEM symptoms, FTD <br>and PMR belong to one underlying latent vector reflecting general psychopathology and, therefore, <br>may be used as an overall severity of schizophrenia (OSOS) index. The bi-dimensional concept of <br>positive and negative symptoms and type I and II schizophrenia is revised.

scholarly journals Schizophrenia phenomenology revisited: positive and negative symptoms are strongly related reflective manifestations of an underlying single trait indicating overall severity of schizophrenia

2019 ◽  
Author(s):  
Abbas F. Almulla ◽  
Hussein Kadhem Al-Hakeim ◽  
Michael Maes
Keyword(s):  
Convergent Validity ◽  
Negative Symptoms ◽  
Supervised Machine Learning ◽  
Machine Learning Techniques ◽  
Stable Phase ◽  
Type I ◽  
Latent Vector ◽  
Thought Disorders ◽  
Symptom Domains ◽  
Positive And Negative Symptoms

Schizophrenia comprises various symptom domains the two most important being positive <br>and negative symptoms. Nevertheless, using (un)supervised machine learning techniques it was <br>shown that a) negative symptoms are significantly interrelated with PHEM (psychosis, hostility, <br>excitation, and mannerism) symptoms, formal thought disorders (FTD) and psychomotor <br>retardation (PMR); and b) stable phase schizophrenia comprises two distinct classes, namely Major <br>Neuro-Cognitive Psychosis (MNP, largely overlapping with deficit schizophrenia) and Simple <br>NP (SNP). In this study, we recruited 120 MNP patients and 54 healthy subjects and measured the <br>above-mentioned symptom domains. In MNP, there were significant associations between <br>negative and PHEM symptoms, FTD and PMR. A single latent trait, which is essentially <br>unidimensional, underlies these key domains of schizophrenia and additionally shows excellent <br>internal consistency reliability, convergent validity, and predictive relevance. Confirmatory Tedrad <br>Analysis indicates that this latent vector fits a reflective model. Soft Independent Modeling of <br>Class Analogy (SIMCA) shows that MNP (diagnosis based on negative symptoms) is better <br>modeled with PHEM symptoms, FTD and PMR than with negative symptoms. In conclusion, in <br>MNP, a restricted sample of the schizophrenia population, negative and PHEM symptoms, FTD <br>and PMR belong to one underlying latent vector reflecting general psychopathology and, therefore, <br>may be used as an overall severity of schizophrenia (OSOS) index. The bi-dimensional concept of <br>positive and negative symptoms and type I and II schizophrenia is revised.

scholarly journals Chronic Fatigue and Fibromyalgia Symptoms are Key Components of Deficit Schizophrenia and are Strongly Associated with Activated Immune-Inflammatory Pathways

2019 ◽  
Author(s):  
Abbas Almulla ◽  
Hussein Al-Hakeim ◽  
Mokhlad Abed ◽  
André Carvalho ◽  
Michael Maes
Keyword(s):  
Convergent Validity ◽  
Rating Scale ◽  
Somatic Symptoms ◽  
Internal Consistency Reliability ◽  
Chronic Fatigue ◽  
Psychomotor Retardation ◽  
Deficit Schizophrenia ◽  
Thought Disorders ◽  
Symptom Domains

A subset of patients with schizophrenia experience physio-somatic symptoms reminiscent of chronic fatigue and fibromyalgia. In schizophrenia, these symptoms contribute to impaired quality of life, and are strongly related to neuro-cognitive deficits, and increased IgA responses to tryptophan catabolites. Negative and PHEM (psychosis, hostility, excitation, mannerism) symptoms, psychomotor retardation (PMR) and formal thought disorders, appear to be manifestations of a single trait reflecting overall severity of schizophrenia (OSOS). In this study, 120 patients with deficit schizophrenia (DEFSCZ) and 54 healthy subjects were assessed with the FibroFatigue (FF) rating scale, and the above-mentioned symptom domains as well as neuro-cognitive tests and biomarkers were measured. In DEFSCZ, there were robust associations between the FF score and all above-mentioned symptom domains, and impairments in semantic and episodic memory and executive functions. Furthermore, the FF score loaded highly on an OSOS latent vector (LV), which showed adequate convergent validity, internal consistency reliability and predictive relevance and fitted a reflective model. Soft Independent Modelling of Class Analogy (SIMCA) showed that the FF items discriminated DEFSCZ from controls with an overall accuracy of 100%. Interleukin IL-1&beta;, IL-1 receptor antagonist (sIL-1RA), tumour necrosis factor (TNF)-&alpha; and CCL-11 (eotaxin) explained 66.8% of the variance in the FF score and 59.4% of the variance in OSOS. In conclusion, these data show that physio-somatic symptoms are a core component of the phenomenology of DEFSCZ and are largely mediated by neurotoxic effects of activated immune pathways, including aberrations in CCL-11, IL-1&beta; and TNF-&alpha; signalling.

Development and Construct Validation of the German Workplace Trust Survey (G-WTS)

2010 ◽  
Vol 26 (1) ◽  
pp. 3-10 ◽  
Author(s):  
Nale Lehmann-Willenbrock ◽  
Simone Kauffeld
Keyword(s):  
Convergent Validity ◽  
Affective Commitment ◽  
Discriminant Validity ◽  
Organizational Context ◽  
Organizational Trust ◽  
Three Dimensional ◽  
Future Research ◽  
Work Related ◽  
Reliable Assessment ◽  
Workplace Trust

In research on trust in the organizational context, there is some agreement evolving that trust should be measured with respect to various foci. The Workplace Trust Survey (WTS) by Ferres (2002) provides reliable assessment of coworker, supervisor, and organizational trust. By means of a functionally equivalent translation, we developed a German version of the questionnaire (G-WTS) comprising 21 items. A total of 427 employees were surveyed with the G-WTS and questionnaires concerning several work-related attitudes and behaviors and 92 of these completed the survey twice. The hypothesized three-dimensional conceptualization of organizational trust was confirmed by confirmatory factor analysis. The G-WTS showed good internal consistency and retest reliability values. Concerning convergent validity, all of the three G-WTS dimensions positively predicted job satisfaction. In terms of discriminant validity, Coworker Trust enhanced group cohesion; Supervisor Trust fostered innovative behavior, while Organizational Trust was associated with affective commitment. Theoretical and practical contributions as well as opportunities for future research with the G-WTS are discussed.

Development of the Fear of Intimacy Components Questionnaire (FICQ)

2015 ◽  
Vol 31 (4) ◽  
pp. 302-309 ◽  
Author(s):  
Maria Pedro Sobral ◽  
Maria Emília Costa
Keyword(s):  
Convergent Validity ◽  
Discriminant Validity ◽  
Two Dimensions ◽  
Dimensional Structure ◽  
Future Research ◽  
Fear Of Intimacy ◽  
Confirmatory Factor Analyses ◽  
New Instrument ◽  
Confirmatory Factor ◽  
Test Retest Reliability

Abstract. We developed a new instrument designed to measure fear of intimacy in romantic relationships. We suggest assessing fear of intimacy through two dimensions: self-revelation and dependence. The Fear of Intimacy Components Questionnaire (FICQ) was validated across three studies in which a 10-item solution systematically emerged. Consistently with a two component perspective, a two-factor solution fitted data the best: fear of losing the self (FLS) and fear of losing the other (FLO). Qualitative analyses verified content validity. Exploratory and confirmatory factor analyses tested the factor structure. Multigroup analyses supported the structural invariance across gender, age, and relationship status. Both factors showed adequate discriminant validity and internal consistency, and good 3-week period test-retest reliability. Associations between the FICQ and insecure attachment orientations demonstrated convergent validity. The association between the FICQ and relationship satisfaction above and beyond a preexisting measure offered criterion validity. By going beyond traditional self-revelation-focused conception of fear of intimacy, that is, by proposing a bi-dimensional structure to fear of intimacy, we believe that this new measure will contribute to future research on fear of intimacy.

PENGEMBANGAN SKALA LOCUS OF CONTROL

2017 ◽  
Vol 2 (3) ◽  
pp. 417-424
Author(s):  
Hendryadi Hendryadi
Keyword(s):  
Locus Of Control ◽  
Internal Consistency ◽  
Convergent Validity ◽  
Discriminant Validity ◽  
Short Form ◽  
Employee Selection ◽  
Future Research ◽  
Validity And Reliability ◽  
Control Scale ◽  
Two Stages

This article aims to develop a short form of the locus of control scale. The study was conducted in two stages: a study of 66 respondents as pilot testing which aims to test content validity, structure validity, and internal consistency. Study 2 was conducted on 328 respondents used to test the validity and reliability of the scale evaluated by the PLS-SEM method (such as internal consistency, convergent validity, and discriminant validity). The analysis concludes that the 8-item locus of control scales tested have adequate validity and reliability. A short form locus of control scale was developed and validated in this study, so it can be used in future research and evaluation for HR management practitioners in employee selection Keywords: locus of control, EFA, CFA, scale construction

scholarly journals DARBUOTOJŲ PSICHOLOGINIS ĮGALINIMAS: LIETUVIŠKOJO TYRIMO METODO PSICHOMETRINĖS CHARAKTERISTIKOS

Psichologija ◽  
2013 ◽  
Vol 47 ◽  
pp. 44-60
Author(s):  
M. Tvarijonavičius ◽  
D. Bagdžiūnienė
Keyword(s):  
Intrinsic Motivation ◽  
Psychometric Properties ◽  
Convergent Validity ◽  
Discriminant Validity ◽  
Psychological Empowerment ◽  
Reliability And Validity ◽  
Future Research ◽  
Internal Reliability ◽  
Five Dimensions ◽  
Motivation Scale

Straipsnyje analizuojama darbuotojų psichologinio įgalinimo problema, pristatomas lietuviškas psichologinio įgalinimo vertinimo klausimynas ir jo psichometrinės charakteristikos. Metodas parengtas dviem etapais, naudojant empirinę skalių konstravimo strategiją. Pirmajame etape, taikant grupinio interviu ir ekspertinio vertinimo metodus, parengti psichologinio įgalinimo vertinimo teiginiai. Antrajame etape atliktas empirinis tyrimas (dalyvavo 189 tiriamieji, reprezentuojantys 8 Lietuvos organizacijas). Remiantis jo rezultatais parengtas lietuviškas psichologinio įgalinimo vertinimo klausimynas. Tiriamosios faktorių analizės metodu išskirti penki faktoriai: prasmė, entuziazmas, sprendimų priėmimas, autonomija ir pasitikėjimas kompetencija. Klausimynas pasižymi dideliu vidiniu patikimumu (bendras Cronbacho α = 0,909, atskirų subskalių nuo 0,755 iki 0,880), dideliu konvergentiniu ir diskriminantiniu konstrukto validumu tiek viso klausimyno, tiek atskirų penkių skalių lygmeniu.Pagrindiniai žodžiai: psichologinis įgalinimas, psichologinio įgalinimo klausimynas, patikimumas, validumas.EMPLOYEE PSYCHOLOGICAL EMPOWERMENT: PSYCHOMETRIC PROPERTIES OF THE LITHUANIAN QUESTIONNAIREMantas Tvarijonavičius, Dalia Bagdžiūnienė SummaryEmployee psychological empowerment is treated as a multidimensional construct manifesting in several dimensions. It has been researched for several decades using various scales depending on the definition of psychological empowerment chosen by a reasercher. However, there is a lack of widely applicable, compact instruments for a reliable and valid assessment of psychological empowerment. Furthermore, there has been a lack of empowerment research in Lithuania. Therefore, the purpose of this study is to construct a Lithuanian psychological empowerment questionnaire and to evaluate its psychometric properties (reliability and validity).The strategy of the empirical construction of a questionnaire was used. At first, statements to describe the concept of psychological empowerment were generated, using group interviews and expert evaluation. Fifteen final items were included into the Lithuanian Psychological Empowerment Questionnaire (LPEQ). Then, an empirical research was performed: 189 respondents from 8 organizations filled up the LPEQ, G.M. Spreizer (1995) Psychological Empowerment Questionnaire (PEQ), B. E. Ashforth (1990) Helplessness Scale, Intrinsic Motivation Scale (Warr et al., 1979), and socio-demografic questions.The results of the study have revealed that the LPEQ has a high internal reliability (Cronbach α = 0.909). Five factors were extracted using the exploratoryfactor analysis, three items each. Psychological empowerment was defined based on five dimensions: meaning, enthusiasm, decision making, authonomy, and trust in competence. The Cronbach α was between 0.755 and 0.880 for the dimension level. These five dimensions show support for the existing models of psychological empowerment (Spreitzer, 1995; Menon, 2001), but also they supplement these models with for instance, the dimension of enthusiasm.The convergent validity of the LPEQ was confirmed by strong correlations (p < 0.01) between the LPEQ and the PEQ subscales, and the Intrinsic Motivation Scale. It was supported by a negative correlation between the LPEQ subscales and the Helplessness Scale. Based on the analysis of correlations, the discriminant validity of the LPEQ dimensions’ levels was confirmed.In conclusion, the Lithuanian Psychological Empowerment Questionnaire (LPEQ) can be characterized as an instrument with appropriate psychometricproperties for the use in research and practice. Directions for the future research in the field have been offered.Key words: psychological empowerment, psychological empowerment questionnaire, reliability, validity.

Customer Satisfaction via Service Quality Dimensions

2016 ◽  
pp. 1829-1846
Author(s):  
Gyaneshwar Singh Kushwaha ◽  
Shiv Ratan Agrawal
Keyword(s):  
Customer Satisfaction ◽  
Service Quality ◽  
Convergent Validity ◽  
Discriminant Validity ◽  
Future Research ◽  
Validity And Reliability ◽  
Quality Dimensions ◽  
Service Quality Dimensions ◽  
Improve Service Quality ◽  
The Relationship

The purpose of the study is to measure the customer satisfaction via service quality dimensions as a whole and individually in the context of stock broking services. A non probability convenient sampling approach has been used in the study. Respondents have been restricted to those who have the experience of trading in stock market through stock brokers. The sample consisted of 229 valid individual customers from Bhopal (MP), India through structured self-administrated questionnaire. Convergent validity, discriminant validity and reliability of the collected data were measured before testing of the research model. An exploratory factor analysis has been conducted using principal components analysis to determine the dimensions of financial service quality. A linear regression was performed to test the relationship between the service quality dimensions and customer satisfaction. The findings suggest that service quality as a whole and individually have a significant impact on customer satisfaction. The results of the study provide useful information for managers to improve service quality which leads to customer satisfaction. The findings were solely on stock broking services from Bhopal (MP) in India which impacts its generalisability. Replication of the present study might be required in other stock broking markets, to improve generalisability using larger samples. Another potential area for future research could be the link between service quality dimensions, customer satisfaction and customer loyalty and customer retention at stock broking services. The study is important considering the economic advantages of satisfying and retaining current customers as opposed to seeking for new customers which is essential in stock broking services. The paper contributes to the literature on stock broking services in India.

Exploring hotel employees’ regulatory foci and voice behavior: the moderating role of leader-member exchange

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
You-De Dai ◽  
Wen-Long Zhuang ◽  
Po-Kai Yang ◽  
Yi-Jun Wang ◽  
Tzung-Cheng Huan
Keyword(s):  
Convergent Validity ◽  
Discriminant Validity ◽  
Future Research ◽  
Leader Member Exchange ◽  
Voice Behavior ◽  
Content Type ◽  
Hotel Employees ◽  
Member Exchange ◽  
Moderating Role

Purpose Drawing on leader-member exchange theory and regulatory focus theory, the purpose of this study is to explore the effects of hotel employees’ regulatory foci on their voice behavior and the moderating role of leader-member exchange. Design/methodology/approach The questionnaire includes demographics, regulatory foci, leader-member exchange and voice behavior sections. The data was collected via a survey of 10 international tourist hotels in Taiwan and 479 valid questionnaires were completed. Confirmatory factor analysis and path analysis were used to test the composite reliability, discriminant validity and convergent validity. Multiple regression analysis was used to test the hypotheses. Findings The outcome of this study indicates that both promotion focus and prevention focus can benefit employees’ voice behavior; however, prevention-focused employees have more positive voice behavior than promotion-focused employees. In addition, the leader-member exchange can moderate the relationship between regulatory foci and voice behavior. Originality/value This is an empirical study in the hotel field to examine the moderating effects of leader-member exchange on the relationships between regulatory foci and voice behavior. This research is contributed toward human resource management literature in the hospitality and tourism domain. Practices for managers and suggestions for future research are discussed.

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