Five-factor model of schizophrenia. Initial validation.
ABSTRACT Schizophrenic psychopathology is heterogeneous and multidimensional. Various strategies have been developed over the past several years to assess and measure more accurately discrete domains of psychopathology. One of the more fruitful strategies to investigate more homogenous domains of psychopathology has been the positive-negative syndrome approach. However, this approach is unable to address a number of important issues. Most schizophrenics present a mixed syndrome; the criteria for what constitutes a positive and negative syndrome are variable; distinguishing primary from secondary negative symptoms can be difficult. In order to address some of these problems, we propose the introduction of a five-syndrome model based on a reanalysis of factor analytic procedures used on 240 schizophrenics assessed with the Positive and Negative Syndrome Scale. We present data on a five-factor solution that appears to best fit the psychopathological data and that is supported by three independent and comparable factor analyses; negative, positive, excitement, cognitive, and depression/anxiety domains of psychopathology give patients their individual mark. Data on internal consistency of the five factors and on initial validation using demographic and clinical variables are presented.
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ABSTRACT: Schizophrenia has been linked to impaired performance on a range of visual processing tasks (e.g. detection of coherent motion and contour detection). It has been proposed that this is due to a general inability to integrate visual information at a global level. To test this theory, we assessed the performance of people with schizophrenia on a battery of tasks designed to probe voluntary averaging in different visual domains. Twenty-three outpatients with schizophrenia (mean age: 40±8 years; 3 female) and 20 age-matched control participants (mean age 39±9 years; 3 female) performed a motion coherence task and three equivalent noise (averaging) tasks, the latter allowing independent quantification of local and global limits on visual processing of motion, orientation and size. All performance measures were indistinguishable between the two groups (ps>0.05, one-way ANCOVAs), with one exception: participants with schizophrenia pooled fewer estimates of local orientation than controls when estimating average orientation (p = 0.01, one-way ANCOVA). These data do not support the notion of a generalised visual integration deficit in schizophrenia. Instead, they suggest that distinct visual dimensions are differentially affected in schizophrenia, with a specific impairment in the integration of visual orientation information.PLoS ONE 02/2015; 10(2):e0117951. DOI:10.1371/journal.pone.0117951 · 3.53 Impact Factor
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ABSTRACT: Many with schizophrenia tend to experience problems with the legal system. Yet little is still known about the correlates of the history of incarceration, as well as frequency of misdemeanor and felony convictions within community samples. To explore this question, we gathered legal and substance abuse histories, and assessments of symptoms and neurocognitive function from 96 adults in a nonacute phase of schizophrenia. ANOVA revealed history of incarceration to be linked with more severe drug and alcohol abuse histories, and greater positive symptoms. Greater numbers of misdemeanor convictions were linked to more severe drug and alcohol abuse histories and greater levels of disorganized symptoms, whereas a greater number of felony convictions was only associated with more severe drug abuse histories. A stepwise multiple regression revealed that both the severity of severe drug abuse histories and levels of disorganized symptoms contributed to predicting 24% of the variance in the number of reported lifetime misdemeanor offenses.Journal of Forensic Psychiatry and Psychology 06/2013; 24(3):293-308. DOI:10.1080/14789949.2013.776617 · 0.88 Impact Factor
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ABSTRACT: Objective: This study sought to identify similarities and differences in symptom characteristics at initial presentation of first psychotic episodes in schizophrenia, bipolar disorder and unipolar depression. Methods: The Structured Interview for DSM-IV (SCID) and Positive and Negative Syndrome Scale (PANSS) were administered to consecutive admission study-eligible patients (n=101) presenting for treatment during their first acute phase of psychotic illness. Forty-nine percent of patients met diagnostic criteria for schizophrenia, 29% for psychotic bipolar disorder and 22% for unipolar depression with psychosis. The PANSS was analyzed using five-factor scoring that included Positive, Negative, Cognitive, Excitement, and Depression factors, and composite cluster scores that assessed Anergia, Thought Disturbance, and Paranoia. Results: Schizophrenia and bipolar disorder patients demonstrated significantly more Positive symptoms, Thought Disturbance and Paranoia than unipolar depressed patients. Schizophrenia and unipolar depressed patients demonstrated significantly more Negative symptoms and Anergia than bipolar patients. Patients with schizophrenia reported more severe Cognitive Disorganization than patients with either bipolar disorder or uni-polar depression (p<.05). Conclusions: Findings from this study demonstrate an informative pattern of similarities and differences in the phenomenology of psychotic disorders at first illness presentation. Commonalities in symptom profiles reflect considerable symptom overlap among psychotic disorders and, thus, the importance of multidimen-sional differential diagnosis for these conditions. The differences across disorders in Positive and Negative symptom severity, Thought Disorder, Paranoia, and Anergia, and especially the higher level of Cognitive Disorganization seen in schizophrenia patients, point to clinically informative differences across these disorders that are relevant to clinical diagnostic practice and models of psychopathology. Abstract Introduction