Negative symptoms, defect state and Huber's basic symptoms: a comparison of the concepts

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.

An empirical analysis of latent structures underlying schizophrenic symptoms: a four-syndrome model

Various models of schizophrenia have postulated two syndromes (i.e., positive and negative), although other exploratory factor analyses have suggested a disorganization syndrome. We conducted a confirmatory factor analysis (CFA) on Schedule for the Assessment of Positive Symptoms (SAPS) and Schedule for the Assessment of Negative Symptoms (SANS) items and subscales to assess the latent structure of symptoms reflecting underlying pathological processes. The sample included 253 DSM-IIIR schizophrenic inpatients. Fourteen different models with one, two, three, or four syndromes were compared using CFA for "goodness of fit." The three-syndrome models displayed better fitness than any of the one- or two-syndrome models. All of the three-syndrome models shared the positive and negative dimensions; the third dimension in these three-syndrome models was either the disorganization or Strauss' relational dimensions. In the reported data, a four-syndrome model, including positive, disorganization, negative, and relational dimensions, showed excellent fitness. Despite its limitations, this study suggests the need to explore the validity of a four-syndrome model. The positive-negative model fits poorly with the data.

Subjective experiences in schizophrenia: a critical review

The current status of subjective experiences in schizophrenia is examined. Subjective experiences are very frequent disorders in schizophrenic patients, and their study has been largely neglected. Recently, a number of scales that evaluate subjective experiences have been published, and although the psychometric properties of most scales have not been sufficiently studied, they seem to have adequate interrater reliability, internal consistency, and convergent validity. A higher number of subjective experiences is associated with the female sex and is inversely correlated with the level of education and lack of insight into illness. Hypothetically, subjective experiences are ascribed to impairments of information processing; however, studies on the relationship between these symptoms and measures of information processing are scarce and contradictory. In the acute stage of the illness, subjective experiences are associated with positive symptoms, and at this stage they may reflect the process activity of schizophrenia. In the remission stage of the illness, subjective experiences are related to negative symptoms, and they constitute the subjective correlate of the psychological deficit. A theory of subjective experiences within the framework of the vulnerability/stress model of schizophrenia is proposed.

Delusion of parasitosis or chronic tactile hallucinosis: hypothesis about their brain physiopathology

The abnormal belief of having the skin infested by parasites is a syndrome with different etiologies. Approximately 12% of cases are induced by another patient with the same syndrome. In noninduced cases, two physiopathological brain mechanisms have been proposed: a delusion, or a primary abnormal tactile sensation with a secondary delusional elaboration. These two hypotheses have been characterized by Berrios as cognitive and sensorialist approaches, respectively. Although modern literature defines this syndrome as a delusion, early literature, particularly German, described both approaches, and even emphasized the sensorialist approach, classifying it as a chronic tactile hallucinosis. A thorough review of the literature suggests both mechanisms may be possible.