Biomedical subjects

V Peralta

Publications and source records attributed to V Peralta.

At least 37 records · Page 2Linked to original sources

PubMed1999

Dimensional structure of psychotic symptoms: an item-level analysis of SAPS and SANS symptoms in psychotic disorders.

The factor structure of psychotic symptoms as assessed by means of the Scales for the Assessment of Positive and Negative Symptoms (SAPS and SANS) was examined in a sample of 660 psychotic inpatients. Analyses were conducted at item-level. Principal-component analysis (PCA) was used to extract factors, the OBLIMIN procedure to rotate factors, and the eigen value greater-than-one criterion to determine the number of factors. PCA resulted in 11 interpretable factors explaining 64% of the total variance: poverty of affect/speech, thought disorder/inappropriate affect, bizarre delusions, social dysfunction, other delusions, paranoid delusions, bizarre behavior, nonauditory hallucinations, auditory hallucinations, manic thought disorder, and attention. Many of the factors were significantly intercorrelated. A second-order PCA resulted in four second-order factors, the first three roughly corresponding to the well-known psychosis, disorganization and negative dimensions. It is concluded that the factor structure of psychotic symptoms is more complex than is generally acknowledged, and that the dimensions of psychosis, disorganization and negative represent second-order dimensions. The subscale composition of the SAPS and SANS was not supported.

Adult↗

PubMed1999

Serum iron in catatonic and noncatatonic psychotic patients.

BACKGROUND: Since low serum iron has been reported in a variety of neuropsychiatric motor disorders, this study was conducted to examine serum iron in patients with a catatonic disorder. METHODS: Forty catatonic and 40 noncatatonic psychotic patients were studied in relation to serum iron levels. The association of serum iron with other clinical variables was also examined. RESULTS: Catatonics had significantly lower mean serum iron than noncatatonics. Ferropenia (serum iron < 50 micrograms/dL) was significantly more prevalent in the catatonic (35%) than in the noncatatonic (7.5%) group. Severity of catatonic symptoms was inversely correlated with level of serum iron, this being due to the negative catatonic symptoms (r = -.34, p = .002). CONCLUSIONS: A subgroup of catatonic patients had ferropenia. Lower serum iron level was associated with both the presence of a categorically defined catatonic syndrome and the severity of the negative catatonic symptoms.

Adult↗

PubMed1999

Thought disorder in schizophrenia. Testing models through confirmatory factor analysis.

Theoretical and empirical models of thought disorder (ThD) were tested through Confirmatory factor analysis (CFA). A sample of 253 DSM-III-R acute schizophrenic patients consecutively admitted was studied. A semistructured interview for schizophrenia was used for diagnosis, and ThD was assessed by means of the Thought, Language, and Communication scale (TLC). Nine ThD models comprising the 18 symptoms of the TLC were tested (ranging from a null model to a six-factor model). The six-dimension model achieved the best fit to the data, although no perfect fit was found. ThD dimensions included in this model were Disorganization, Negative, Idiosyncratic, Semantic, Attentional, and Referential dimensions. The TLC was close to capture adequately these underlying constructs. The Disorganization and the Negative dimensions received more validity on conceptual and psychometric grounds than the remaining dimensions. Thought Disorder multidimensional models fitted the data better than one-dimension models. Thought Disorder dimensions would be potential markers for biological, neurophysiological, and neuropsychological studies of schizophrenic disorder.

Adolescent↗

PubMed1999

Premorbid personality in psychoses.

This study aimed to establish correlates of the dimensions of schizophrenia in the premorbid personality traits of patients. A sample of 112 patients of relatively recent illness onset who were admitted for a psychotic episode were assessed with a semistructured interview for schizophrenia. Positive and negative symptoms were evaluated with the Scale for the Assessment of Positive Symptoms and the Scale for the Assessment of Negative Symptoms at the time of hospital discharge; positive, negative, and disorganization scores were obtained from these scales. Premorbid personality was assessed blindly through a partially modified version of the Personality Assessment Schedule using interviews with the parents or a close relative. Schizoid traits were significantly associated with negative and positive dimensions. Sociopathic traits were related to the disorganization dimension. Trends toward significance were obtained between passive-dependent traits and the negative and disorganization dimensions, and between the schizotypal dimension and the positive dimension. Partial correlational analyses were used to control for the effect of the remaining personality dimensions on the above relationships. Schizoid premorbid traits were still significantly related to the negative dimension but to a lesser degree to the disorganization and positive dimensions. The association between sociopathic premorbid traits and the disorganization dimension remained significant. These results suggest the preexistence of a three-dimensional structure predisposing to psychoses within the premorbid personality; this structure is more evident in patients with short illness duration.

Adult↗

PubMed1999

High levels of Olea europaea pollen and relation with clinical findings.

BACKGROUND: Olea europaea pollen is an important cause of seasonal allergic rhinitis and bronchial asthma in southern Spain. For patients allergic to grass pol- len the critical concentration of airborn pollen is 50 grains/m3, but in the case of Olea pollinosis no data is available. METHODS: Fifty-six seasonal allergic rhinitis patients (29 in 1994 and 27 in 1995) were included in this study, all of whom lived in Jaen. Daily symptom card were filled in and pollen counts during May and June were performed in both years. A linear regression model was used for analysis of the airborne pollen concentration and the symptom score. RESULTS: Significant correlations among daily counts of Olea pollen and rhinitis symptoms were obtained. Most of our monosensitized patients needed a high Olea pollen concentration in the atmosphere (around 400 grains/m3) to suffer at least from mild allergic rhinitis symptoms. CONCLUSION: Local conditions with a wide area dedicated to olive tree cultivars result in a high concentration of this pollen in the atmosphere. Monosensitized Olea patients in our area seem to need exceptionally high levels to suffer from allergic symptoms.

Adolescent↗

PubMed1999

Diagnostic significance of Schneider's first-rank symptoms in schizophrenia. Comparative study between schizophrenic and non-schizophrenic psychotic disorders.

BACKGROUND: Despite the lack of consistent empirical support, modern diagnostic criteria of schizophrenia give particular emphasis to Schneider's first-rank symptoms (FRSs). AIMS: To examine the diagnostic significance of FRSs for schizophrenia by trying to overcome the limitations of previous studies. METHODS: This study examined the diagnostic accuracy of FRSs for schizophrenia in 660 in-patients with the full spectrum of functional psychotic disorders. Schizophrenia was diagnosed according to three criteria: DSM-III-R broad, DSM-III-R narrow and Feighner, the latter being considered as the gold standard because it does not give particular emphasis of FRSs. RESULTS: FRSs were highly prevalent in both schizophrenia and non-schizophrenic psychoses. The likelihood ratios (and 95% CI) of one or more FRSs for Feighner, DSM-III-R narrow and DSM-III-R broad schizophrenia were 1.06 (0.94-1.20), 1.23 (1.09-1.39) and 1.73 (1.44-2.08), respectively. These data indicate that FRSs do not significantly increase the likelihood of having schizophrenia. CONCLUSIONS: FRSs are not useful in differentiating schizophrenia from other psychotic disorders. Diagnostic systems for schizophrenia that are heavily based on these symptoms may arise from a tautological definition of the disorder.

Adult↗

PubMed1998

Illness duration and neuropsychological impairments in schizophrenia.

This study aims to verify whether cognitive disturbances in schizophrenic patients are associated with illness duration, and to examine the influence of other covariates on neuropsychological disturbances. Sixty-nine consecutive admissions of schizophrenic patients (DSM-III-R, APA, 1987) were included to an acute psychiatric unit. Patients were evaluated by a semistructured interview and assessed with the Scale for the Assessment of Positive Symptoms (SAPS) and the Scale for the Assessment of Negative Symptoms (SANS). A wide neuropsychological battery, adapted to Spanish, was used. Variables were transformed to z-scores when their distribution was normal, or to log-values in the case of non-normal distributions. Pearson's correlation coefficients with a Bonferroni correction showed strong relationships between illness duration and cognitive performance in neuropsychological tests on visuomotor processes and delayed visual memory. In order to examine the influence of potential covariates on neuropsychological disturbances, stepwise multiple regression procedures were performed with each neuropsychological measure as a dependent variable, and years of education, age, gender, neuroleptic does in chlorpromazine equivalents, biperidene doses and illness duration as independent variables. The longer the illness duration, the poorer the performance on visuomotor process and delayed visual memory tasks. Moreover, the neuropsychological disturbances associated with illness duration were different from those related to aging, educational background, gender and treatment status. These findings suggest the existence of a relationship between cognitive decline in visuomotor and delayed visual memory functions and the length of schizophrenic illness.

Adolescent↗

PubMed1998

Factor structure and clinical validity of competing models of positive symptoms in schizophrenia.

BACKGROUND: The factor structure of four competing models of positive symptoms and their clinical validity was studied in a sample of 253 schizophrenia inpatients. METHODS: The following models were tested using confirmatory factor analysis: a one-dimension severity model, a two-dimension model comprising a psychosis factor and a disorganization factor, a four-dimension model based on the Scale for the Assessment of Positive Symptoms (SAPS) structure in subscales, and a five-dimension model derived from the previous one by further differentiating Schneiderian delusions from non-Schneiderian ones. RESULTS: More complex multifactorial models fit the data better than simpler models. The five-dimension model was the best adjusted (goodness of fit index = .844, nonnormed fit index = .812, normed fit index = .728). Whereas the one-dimension model did not display significant association with the clinical variables, multidimensional models were related to age at onset and illness severity. The two-dimension model captured well the clinical correlates of the more complex models. CONCLUSION: None of the tested models showed good fit to the data. The one-dimension model displayed both poor factor validity and poor external validity; therefore, research relying on the SAPS total score may reach misleading conclusions.

Adult↗

PubMed1998

Lack of insight in mood disorders.

BACKGROUND: The study's aim was to examine insight in mood disorders in relation to type of mood episode, psychotic state, and insight change over the episode. METHODS: Fifty four patients with a manic or major depressive episode were interviewed for insight assessment at admission and discharge. RESULTS: At admission, mania patients had more severe insight impairment that depressive ones, depressive patients with psychosis had poorer insight than those without psychosis, and mania patients had poor insight irrespective of the presence of psychotic symptoms. At discharge some insight impairment was observed in mania. CONCLUSION: Lack of insight was a prevalent condition in psychotic depression and mania. LIMITATIONS: A global insight measure was used. Ratings of insight were not blind to the ratings of other symptoms. CLINICAL RELEVANCE: Considering residual insight impairment in mania may be important to maximize compliance and to prevent relapse.

Adult↗

PubMed1998

Psychopathological dimensions and lack of insight in schizophrenia.

The present study investigated the relationships of psychopathological dimensions of schizophrenia with Insight in a sample of 100 acute schizophrenic patients. Lack of insight was significantly correlated with disorganized, excited and negative schizophrenic dimensions but not with other Positive and Negative Syndrome Scale dimensions. In addition, when insight was assessed through a multidimensional approach, a variety of relationships with the schizophrenic dimensions were found.

Adolescent↗

PubMed1997

Factor structure of symptoms in functional psychoses.

Global ratings from the Scale for the Assessment of Positive Symptoms and Scale for the Assessment of Negative Symptoms were subjected to principal-component analysis (PCA) in 80 schizophrenia patients, 76 patients with schizophreniform disorder, 80 patients with schizoaffective and mood disorders, and 78 patients with delusional, brief reactive, and atypical psychoses. The resulting factors were correlated with depressive, manic, and catatonic syndromes, and subjected to a multivariate analysis of variance across DSM-III-R diagnoses. PCAs revealed that psychosis, disorganization, and negative factors were also present in each of the nonschizophrenic groups. The disorganization factor tended to be related to the manic syndrome, and the negative factor to depressive and catatonic syndromes. Overall, the three factors had little diagnostic relevance in functional psychoses, although the negative factor was relatively more characteristic of schizophrenia. The data suggest that positive, negative, and disorganization factors are not specific to schizophrenia; this is consistent with a dimensional view of psychopathology in functional psychoses.

Adult↗

PubMed1996

Abnormal subjective experiences in schizophrenia: its relationships with neuropsychological disturbances and frontal signs.

The prevalence of abnormal subjective experiences is high in schizophrenic patients. This study starts from the hypothesis that these subjective disorders are associated with cognitive disturbances. In order to test this hypothesis a study was carried out on 40 patients who were diagnosed as suffering from schizophrenia according to RDC and DSM-III-R criteria. They were consecutively admitted due to a recrudescence of their symptomatology. Version 3 of the Frankfurt Complaint Questionnaire, adapted for Spanish by the authors, was used as an instrument for the assessment of subjective experiences. Eight patients refused to answer the questionnaire. A neuropsychological battery, including the Mini-Mental State, some subtests from the WAIS, Bender's visual-motor test, Rey's Complex Figure, and the Trail Making Test, was used. Frontal neurological signs were evaluated. The abnormal subjective experiences of schizophrenics presented a close association with neuropsychological disturbances and, to a lesser degree, of intensity with frontal neurological signs. Regression analyses by means of stepwise method and partial correlation analyses were undertaken. Many significant relationships between subjective experiences and cognitive disturbances persisted after controlling the influence of age, gender, education, lack of insight, neuroleptic doses, and biperidene doses.

Adult↗

PubMed1996

Neurological frontal signs and neuropsychological deficits in schizophrenic patients.

A higher prevalence of neurological signs (NS) has been described in schizophrenic patients when compared with controls or patients with other mental illnesses. This study, which includes a sample of 66 DSM-IIIR schizophrenics, was designed to assess the relationship between 7 frontal neurologic signs described by Luria and cognitive disturbances measured by an exhaustive neuropsychological battery. There was a statistically significant relationships between the frontal signs and the cognitive deficits (mean shared variance was 22%) which persisted after correcting for the influence of age, education, and duration of illness.

Adolescent↗

PubMed1996

Factor analysis of the Frankfurt Complaint Questionnaire in a Spanish sample.

The Frankfurt Complaint Questionnaire (FCQ) is a self-assessment instrument designed to evaluate the subjective experiences (SE) of psychotic patients. It is composed of 98 yes-no items grouped in ten phenomenological subscales. The original validation of the FCQ included a factor analysis with a four-factor structure. No further studies of factor validity have been carried out. The present study aimed to replicate the factor structure of the FCQ in a Spanish sample. The sample was composed of 286 consecutively admitted patients due to a recrudescence of their psychotic symptoms. They were evaluated through a semistructured interview for schizophrenia and diagnosed according to DSM-III-R criteria. Organic mental disorders were excluded. Sixteen patients who failed to fulfill the FCQ were excluded. The sample finally comprised 270 patients. A factor structure of FCQ items comprising 25 factors was found. The first factor obtained the highest explained variance, and most items obtained their highest load on the first factor. These results strongly suggest a unidimensionality underlying FCQ items. A new scale composed of 18 items was derived from those with higher weights in the first factor. The new scale of SE was presented in a Likert format to demonstrate their frequency and intensity more clearly.

Adult↗

PubMed1996

Symptoms of the schizophrenic negative syndrome.

BACKGROUND: The aim was an investigation of the symptom composition of the negative syndrome of schizophrenia. METHOD: A hundred schizophrenic patients were assessed with various rating scales for positive and negative symptoms and typological criteria. A subgroup with a negative syndrome was defined, and a discriminant analysis performed using symptoms from the Scale for the Assessment of Negative Symptoms (SANS) as discriminant variables. RESULTS: The discriminant function classified 92% of patients correctly. All but four SANS symptoms (inappropriate affect, both attentional items and blocking) were significantly correlated with the discriminant function. CONCLUSIONS: With the exception of some items, the SANS seems to capture adequately the negative syndrome of schizophrenia.

Adult↗

PubMed1995

Cognitive disorders in the positive, negative, and disorganization syndromes of schizophrenia.

Recent factor-analytic studies have derived several trisyndromic models for schizophrenia, all based on the positive, negative, and disorganization syndromes. The goal of this study was to examine cognitive disorders in these three schizophrenic syndromes. The study group was composed of 40 schizophrenic patients consecutively admitted to the hospital due to a recrudescence of their symptomatology. They were selected on the basis of a semistructured interview, diagnosed with DSM-III-R criteria, and evaluated with scales for positive and negative symptoms. Their cognitive disorders were assessed with a battery of neuropsychological tests. The schizophrenic syndromes were weakly associated with cognitive performance through direct correlations and after correction for confounding variables. The disorganization and negative syndromes were more strongly associated with cognitive disturbances than was the positive syndrome, and both were associated with disturbances of visual-motor processes. Moreover, the disorganization syndrome was associated with disturbances in language and verbal memory and in time-controlled performance.

Adolescent↗

PubMed1995

Schizophrenic syndrome and Wisconsin Card Sorting Test dimensions.

A principal component analysis of Wisconsin Card Sorting Test (WCST) scores has recently shown three factors. Only the Perseveration factor may measure the activity of the dorsolateral prefrontal cortex in schizophrenic patients. Liddle has hypothesized that a dysfunction in this area is specifically related to the negative syndrome and not to other schizophrenic syndromes (positive and disorganization). The factor analysis of the WCST was replicated with similar results in 38 schizophrenic or schizoaffective patients. In the total group, the correlation between the negative syndrome and the Perseveration factor did not reach significant levels. In the patients with a DSM-III-R diagnosis of schizophrenia (n = 30), the correlations did reach significant levels.

Adult↗

PubMed1995

Positive and negative symptoms/syndromes in schizophrenia: reliability and validity of different diagnostic systems.

The paper explores the reliability, concurrent validity and overlap of some positive/negative symptom rating scales and typological criteria in 100 schizophrenic patients. Rating scales include Andreasen's Scales for the Assessment of Positive and Negative Symptoms, Abrams and Taylor's Scale for Emotional Blunting, and Kay's Positive and Negative Syndrome Scale. Criteria for categorizing individual patients include Andreasen's and Kay's criteria for positive and negative types of schizophrenia as well as Carpenter's criteria for the deficit syndrome. The correlations among positive as well as among negative scales were high. The agreement among criteria tended to be lower. Both positive scales showed low internal consistency. Kay's negative scale had the greatest internal consistency, which suggests that it is measuring a homogeneous syndrome. All negative symptom scales and categorical syndromes identified a group of patients who were single and exhibited schizoid or schizotypal pre-morbid personality disorders, poor premorbid sexual/social adjustment, poor response to neuroleptics and poor prognosis.

Adolescent↗