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Pál Czobor

Publications and source records attributed to Pál Czobor.

10 recordsLinked to original sources
PubMed2006

Associating functional recovery with neurocognitive profiles identified using partially ordered classification models.

Neurocognitive deficits are a core feature of schizophrenia and a significant cause of functional disability. However, targeting these deficits with new treatment approaches will only yield functional improvements if those cognitive operations that are responsible for different dimensions of functional recovery can be identified. A major challenge is that conventional neuropsychological tests, the most practical tools for broadly sampling cognitive functions in treatment trials, are polyfactorial, so that task performance is influenced by multiple cognitive operations. Hence, it is difficult to pinpoint exactly for which cognitive operations a low scoring subject may have poor functionality. We have previously applied in a neuropsychological test battery administered to 220 patients having schizophrenia or schizoaffective disorder, Bayesian statistical methods (yielding partially ordered sets, or posets) designed to mimic the expert analysis of a neuropsychologist by classifying patients into discrete groupings or "states" each having a unique cognitive profile. Here, we report on the association of attributes describing these states (viz. working memory, capacity for divergent thinking, cognitive flexibility and psychomotor speed) with two domains of functional outcome (work/education and residential functioning) rated up to 18 months later. After multiplicity correction, only working memory was associated with work/education outcome. While working memory was not associated with residential outcome, the remaining three attributes were. These findings suggest that different neurocognitive operations may be responsible for different outcome domains. Findings support the use of the poset methodology for clarifying patterns of relationships between discrete neurocognitive attributes and domains of functional outcome.

Adolescent↗
PubMed2006

Aggression and quantitative MRI measures of caudate in patients with chronic schizophrenia or schizoaffective disorder.

Caudate dysfunction is implicated in schizophrenia. However, little is known about the relationship between aggression and caudate volumes. Forty-nine patients received magnetic resonance imaging scanning in a double-blind treatment study in which aggression was measured. Caudate volumes were computed using a semiautomated method. The authors measured aggression with the Overt Aggression Scale and the Positive and Negative Syndrome Scale. Larger caudate volumes were associated with greater levels of aggression. The relationship between aggression and caudate volumes may be related to the iatrogenic effects of long-term treatment with typical antipsychotic agents or to a direct effect of schizophrenic processes on the caudate.

Adult↗
PubMed2005

Quantitative MRI measures of orbitofrontal cortex in patients with chronic schizophrenia or schizoaffective disorder.

The relationship between orbitofrontal cortex (OFC) volumes and functional domains in treatment-resistant patients with schizophrenia or schizoaffective disorder is poorly understood. OFC dysfunction is implicated in several of the behaviors that are abnormal in schizophrenia. However, little is known about the relationship between these behaviors and OFC volumes. Forty-nine patients received magnetic resonance imaging scanning as part of a double-blind treatment study in which psychiatric symptomatology, neuropsychological function, and aggression were measured. OFC volumes were manually traced on anatomical images. Psychiatric symptomatology was measured with the Positive and Negative Syndrome Scale (PANSS). Aggression was measured with the Overt Aggression Scale (OAS) and with the PANSS. Neuropsychological function was assessed using a comprehensive test battery. Larger right OFC volumes were associated with poorer neuropsychological function. Larger left OFC gray matter volumes and larger OFC white matter volumes bilaterally were associated with greater levels of aggression. These findings are discussed in the context of potential iatrogenic effects.

Adult↗
PubMed2005

Quantitative craniofacial anomalies in a racially mixed schizophrenia sample.

BACKGROUND: The observation that some patients with schizophrenia display subtly anomalous craniofacial features dates back to the early 1900s and has recently been hypothesized to reflect disrupted prenatal development also involving the brain. Most studies to date have used observer ratings rather than physical measurements and have studied only Caucasian samples. Our objective was to determine whether schizophrenia is associated with craniofacial anomalies applying quantitative methods in Caucasian and African American subjects. METHODS: Participants were 32 Caucasian and 20 African American outpatients aged 18 to 60, meeting Structured Clinical Interview for DSM-IV (SCID) confirmed criteria for schizophrenia/schizoaffective disorder, recently discharged from a psychiatric hospital in Queens, New York. The healthy control subjects were recruited through local advertisements and were individually matched to the patient sample on gender, race, and age. RESULTS: Thirty-two measurements of the head and face reflecting all regions of potential developmental significance were taken according to published methods and validated for this study. Significantly greater skull base width [F(1,51) = 13.11, p = .0005] and greater height of the cutaneous lower lip [F(1,51) = 7.90, p = .0059] were found among patients after applying multiplicity correction. Statistical correction for group differences in body weight did not alter the findings. CONCLUSIONS: Findings agree with the two major anthropometric studies in schizophrenia.

Adolescent↗
PubMed2003

Basic neuropsychological dimensions in schizophrenia.

Neuropsychological (NP) studies in schizophrenia often require data reduction to avoid statistical type I error from multiple comparisons. Typically, this involves grouping measures into domains defined by experts a priori based on delineations validated in brain-injured but not schizophrenia samples (e.g. attention, executive functioning, memory, language visuospatial, motor). Component measures are arbitrarily selected and validity may not generalize to different samples or within the same sample over time. One solution to these problems is illustrated using neurocognitive subdomains based on recent schizophrenia literature, and validated with data from a longitudinal study (156 subjects) involving repeated NP testing (baseline--within 6 months of hospital discharge--and 6 and 18 months later). A priori subdomains were grouped and submitted to principal component analysis (PCA) at each time point. Longitudinal stability of the resulting factors was tested by computing congruency coefficients. Six stable factors were extracted having good construct, divergent and predictive validity. Five neuropsychological measures frequently studied in schizophrenia were not correlated with these factors, suggesting that they should be maintained as independent neurocognitive subdomains. Distinct factors for executive functioning, verbal memory and motor functions could not be validated; this raises concerns about conclusions of previous studies regarding the pattern, severity and correlates of specific neurocognitive functions in schizophrenia.

Adult↗
PubMed2003

The multidimensional scale of independent functioning: a new instrument for measuring functional disability in psychiatric populations.

The Multidimensional Scale of Independent Functioning (MSIF) is a new instrument for rating functional disability in psychiatric outpatients. The MSIF differs from other disability rating scales by providing discrete ratings of (1) role responsibility, (2) presence and level of support, and (3) performance quality. The MSIF, which consists of a semistructured interview and detailed rating anchors, was validated in 114 psychiatric outpatients. The instrument had good criterion, discriminative, interrater, and construct validity. Correlations between comparable ratings on the Social Adjustment Scale II (SAS II) ranged from 0.78 to 0.86. Nevertheless, redundancy analysis using canonical correlation demonstrated that, although the two instruments overlap, the MSIF contains information that is not contained in the SAS II. Furthermore, there was only modest shared variance with conceptually non-overlapping subscales in the SAS II. Interrater reliability (intraclass correlation coefficients) ranged from 0.74 to 1.00 for global and subscale scores. MSIF subscales performed as expected with respect to external validators such as hours of employment, earned income, supported versus nonsupported employment and housing, and mainstream versus nonmainstream educational status. MSIF global ratings were modestly correlated with IQ and psychopathology ratings, consistent with reports in the literature. Construct validity, estimated using Cronbach's alpha coefficient, was 0.72. The MSIF is a promising new instrument designed to circumvent several limitations with existing functional outcome instruments for longitudinal studies, intervention research, and services research.

Demography↗
PubMed2003

Characteristics of assaultive behavior among psychiatric inpatients.

OBJECTIVE: The purpose of this study was to assess the extent to which psychosis, disordered impulse control, and psychopathy contribute to assaults among psychiatric inpatients. METHODS: The authors used a semistructured interview to elicit reasons for assaults from assailants and their victims on an inpatient research ward. Video monitoring provided supplemental information to confirm participants' identities and activities before and during the assault. RESULTS: Consensus clinical ratings indicated that approximately 20 percent of the assaults in this sample were directly related to positive psychotic symptoms. Factor analysis revealed two psychosis-related factors, one related to positive psychotic symptoms and the other to psychotic confusion and disorganization, as well as a third factor that differentiated impulsive from psychopathic assaults. CONCLUSIONS: Information obtained from interviews with assailants can reveal the underlying causes of specific assaults. This information is potentially useful in the selection of rational antiaggressive treatment strategies.

Consensus↗
PubMed2002

Neurocognitive correlates of the COMT Val(158)Met polymorphism in chronic schizophrenia.

BACKGROUND: Neurocognitive deficits are recognized as a cardinal feature of schizophrenia, but the determinants of these deficits remain unknown. Recent reports have suggested that a functional polymorphism, Val(158)Met in exon III of the catechol-O-methyltransferase gene, shares approximately 4% variance with performance on the Wisconsin Card Sorting Test. These findings led to suggestions that the catechol-O-methyltransferase polymorphism may exert its effects by modulating prefrontal dopamine function, but few other neurocognitive measures have been examined, leaving open questions about phenotypic specificity. METHODS: We examined the effects of the catechol-O-methyltransferase Val(158)Met polymorphism in 58 individuals with chronic schizophrenia who completed a battery of 15 neurocognitive tests, which were reduced to four reliable neurocognitive domain scores. We examined the effects of genotype on these four domains and on global neurocognitive ability. RESULTS: The Met allele was associated with better performance in the Processing Speed and Attention domain, but not with other domain scores measuring executive and visuoperceptual functions, declarative verbal learning and memory, simple motor ability, or global neurocognitive function. Genotype shared approximately 11% of variance with Processing Speed and Attention scores, and approximately 2% of variance with Wisconsin Card Sorting Test scores. CONCLUSIONS: The findings provide independent support for the hypothesis that the catechol-O-methyltransferase Val(158)Met polymorphism influences neurocognitive function in schizophrenia, and suggest that the functional effects may be expressed on measures of Processing Speed and Attention. This information may prompt reconsideration of the "prefrontal dopamine" hypothesis and invites examination of a broader range of effects in efforts to refine the neurocognitive phenotype that is most relevant to variation in catechol-O-methyltransferase expression.

Adult↗
PubMed2002

Antipsychotic-induced weight gain and therapeutic response: a differential association.

This study investigated the association between antipsychotic-induced weight gain and therapeutic response to haloperidol and three commonly used atypical neuroleptic medications in schizophrenia and schizoaffective disorder. The subjects were 151 patients enrolled in a double-blind experiment with a duration of 14 weeks comparing the therapeutic efficacy of haloperidol (n = 36), clozapine (n = 38), olanzapine (n = 38), and risperidone (n = 39). Absolute and relative (%) gain in body weight and body mass index (BMI) was determined for the entire duration of the double-blind treatment period; therapeutic response was assessed by the total score and the individual subscales of the Positive and Negative Symptom Scale. Compared with the pretreatment baseline, results indicated that for olanzapine and clozapine, therapeutic response was closely related to an absolute and relative gain in weight and to a gain in BMI. No association between weight gain and therapeutic response was found for risperidone and haloperidol. These findings suggest that patients who are likely to have the maximal benefits of olanzapine or clozapine treatment for symptom alleviation are at the highest risk of a clinically significant increase in weight gain.

Adult↗