The variable results of positive-negative research with schizophrenics underscore the importance of well-characterized, standardized measurement techniques. We report on the development and initial standardization of the Positive and Negative Syndrome Scale (PANSS) for typological and dimensional assessment. Based on two established psychiatric rating systems, the 30-item PANSS was conceived as an operationalized, drug-sensitive instrument that provides balanced representation of positive and negative symptoms and gauges their relationship to one another and to global psychopathology. It thus constitutes four scales measuring positive and negative syndromes, their differential, and general severity of illness. Study of 101 schizophrenics found the four scales to be normally distributed and supported their reliability and stability. Positive and negative scores were inversely correlated once their common association with general psychopathology was extracted, suggesting that they represent mutually exclusive constructs. Review of five studies involving the PANSS provided evidence of its criterion-related validity with antecedent, genealogical, and concurrent measures, its predictive validity, its drug sensitivity, and its utility for both typological and dimensional assessment.

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The Positive and Negative Syndrome Scale (PANSS) for Schizophrenia

Objective: Phencyclidine (PCP, “angel dust”) induces a psychotomimetic state that closely resembles schizophrenia. As opposed to amphetamine-induced psychosis, PCP-induced psychosis incorporates both positive (e.g., hallucinations, paranoia) and negative (e.g., emotional withdrawal, motor retardation) schizophrenic symptoms. PCP-induced psychosis also uniquely incorporates the formal thought disorder and neuropsychological deficits associated with schizophrenia. The purpose of the present paper is to review recent advances in the study of the molecular mechanisms of PCP action and to describe their implications for the understanding ofschizophrenic pathophysiology. Methoc�: Twenty-five papers were identified that described the clinicaldose and serum and CSF levelsat which PCP induces its psychotomimetic effects. The dose range ofPCP-induced effects were compared to the dose range at which PCP interacts with specific molecular targets and affects neurotransmission. Results: It was found that PCP-induced psychotomimetic effects are associated with submicromolar serum concentrations of PCP. At these concentrations PCP interacts selectively with a specific binding site (PCP receptor) that is associated with the N-methyl-D-aspartate (NMDA)-type excitatory amino acid receptor. Occupation ofits receptor by PCP induces noncompetitive inhibition of NMDA receptor-mediated neurotransmission. Other NMDA antagonists such as the dissociative anesthetic ketamine induce PCP-like neurobehavioral effects in proportion to their potency in binding to the PCP receptor and inducing NMDA receptor inhibition. Conclusions: These findings suggestthat endogenous dysfunction ofNMDA receptor-mediated neurotransmission might contribute to the pathogenesis of schizophrenia. The relative implications of the PCP and amphetamine models ofschizophrenia are discussedin relationship to the diagnosis and etiology of schizophrenia. (Am J Psychiatry1991;148:1301-1308)

Recent advances in the phencyclidine model of schizophrenia.

Practice guideline for the treatment of patients with schizophrenia

https://focus.psychiatryonline.org/doi/pdf/10.1176/appi.focus.12.2.192

Comparative efficacy and tolerability of 15 antipsychotic drugs in schizophrenia: a multiple-treatments meta-analysis

New advances in the understanding of schizophrenia etiology, course, and treatment have increased interest on the part of patients, families, advocates, and professionals in the development of consensus-defined standards for clinical status and improvement, including illness remission and recovery As demonstrated in the area of mood disorders, such standards provide greater clarity around treatment goals, as well as an improved framework for the design and comparison of investigational trials and the subsequent evaluation of the effectiveness of interventions Unlike the approach to mood disorders, however, the novel application of the concept of standard outcome criteria to schizophrenia must reflect the wide heterogeneity of its long-term course and outcome, as well as the variable effects of different treatments on schizophrenia symptoms As an initial step in developing operational criteria, an expert working group reviewed available definitions and assessment instruments to provide a conceptual framework for symptomatic, functional, and cognitive domains in schizophrenia as they relate to remission of illness The first consensus-based operational criteria for symptomatic remission in schizophrenia are based on distinct thresholds for reaching and maintaining improvement, as opposed to change criteria, allowing for alignment with traditional concepts of remission in both psychiatric and nonpsychiatric illness This innovative approach for standardizing the definition for outcome in schizophrenia will require further examination of its validity and utility, as well as future refinement, particularly in relation to psychosocial and cognitive function and dysfunction These criteria should facilitate research and support a positive, longer-term approach to studying outcome in patients with schizophrenia

/pdf/remission-in-schizophrenia-proposed-criteria-and-rationale-3m92kxf73k.pdf

Remission in Schizophrenia: Proposed Criteria and Rationale for Consensus

The Positive and Negative Syndrome Scale (PANSS) consists of a formalized clinical interview and 30 operationally defined items for psychopathology assessment. We report here on the psychometric equivalence of a Spanish language adaptation (PANSS-S), developed to facilitate minority group, multinational, and cross-cultural studies on schizophrenia. Two bilingual psychiatrists simultaneously rated 57 psychiatric inpatients using the PANSS (N = 20), PANSS-S (N = 20), or both methods (N = 17). The PANSS-S demonstrated sound interrater reliabilities (r = .93 for positive and .74 for negative syndrome, p less than .001), which were similar to those from the current PANSS assessment and original standardization studies. In support of criterion-related validity, the means and variance of the two instruments were comparable, and significant cross-correlations were obtained for the principal scales (r = .92 for positive and .83 for negative syndrome, p less than .0001), component symptoms, and five additional psychopathology clusters. The results suggest that the PANSS-S has psychometric properties resembling those of the PANSS and may be used interchangeably in a Spanish-speaking population.

The Positive and Negative Syndrome Scale—Spanish Adaptation

Positive and Negative Syndrome Scale

The construct validity and extended stability of positive and negative syndromes were studied via multidimensional cross-sectional assessment of 134 schizophrenics in the acute, chronic, and long-term chronic stages. For all groups the syndromes were internally reliable, not significantly intercorrelated, and of similar severity. The syndromal correlates with clinical, motor, historical, and genealogical dimensions, however, differed as a function of chronicity. In acute schizophrenics, a negative syndrome was associated with clinical and genealogical indicators of good prognosis, whereas the converse obtained for a positive syndrome in the acute stage and a negative syndrome in the chronic stage. The relationship of education, marital status, and attention disorder to the positive-negative distinction also varied according to length of illness. Its meaning, therefore, appeared phase-specific and subject to evolution, obviating generalizations across all phases. Implications for theory, prognosis, current research, and future study are presented.

Abraham Fiszbein

Papers

The Positive and Negative Syndrome Scale (PANSS) for Schizophrenia

The Positive and Negative Syndrome Scale—Spanish Adaptation

Positive and Negative Syndrome Scale

Positive and negative syndromes in schizophrenia as a function of chronicity.

SCID-PANSS: Two-tier diagnostic system for psychotic disorders