[Balint groups].

At the end of the last century, Hughlings-Jackson suggested that positive and negative syndromes should be kept apart in psychotic disorders. When the concepts of dementia praecox and schizophrenia were introduced by Kraepelin and Bleuler, emphasis was laid on the negative symptoms, regarded as fundamental. After the introduction of the "first rank symptoms" by Schneider emphasis switched to the positive symptoms in schizophrenia and these symptoms were included in most diagnostic criteria. In the 1980s Andreasen and Crow suggested a dichotomy into positive and negative syndromes in schizophrenia. Kay and co-workers introduced a Positive And Negative Syndrome Scale (PANSS) for schizophrenia. In the original studies satisfactory construct validity and inter-rater reliability were demonstrated. However, in studies outside the USA a high construct validity was found for the negative scales but not for the positive and general psychopathology scales. Furthermore, the inter-rater reliability of the negative scale was a problem. After introduction of the Structured Clinical Interview for the PANSS (SCI-PANSS) the inter-rater reliability increased for all three scales. In an early study Kay and Sevy found seven factors in a principal component analysis of the PANSS and suggested a four factor pyramidical model. Later principal component analyses by Lepine, Peralta et al. and Kawasaki et al. suggested that the four factor model was an oversimplification and Lindström and von Knorring suggested a five factor pyramidical model. A similar model was later suggested by Bell et al. after a reanalysis of the original series of Kay and Sevy.(ABSTRACT TRUNCATED AT 250 WORDS)

Affective Symptoms↗

PubMed1995

The negative component in schizophrenia.

Many conflicts in the literature about negative symptoms arise because different authors use different definitions of negative symptoms. If narrow definitions are used, it appears that drugs have little effect against negative symptoms, although those who use broader definitions tend to conclude that negative symptoms do respond to drugs. Another complication is that negative symptoms may be secondary to other causes, such as psychotic symptoms, the side effects of drugs, depression and understimulation as a result of hospitalisation. Attempting to measure drug effects on negative symptoms can be complicated by such factors as different co-medication in the test and control groups and different pharmacological profiles of test and standard drugs, in particular in terms of extrapyramidal side effects or antidepressant effects. Several approaches to dissecting the direct effect of drugs from their indirect effects on negative symptoms have included analyses of covariance, regression analyses and path analyses. Applying path analysis to the data from the North American clinical trial of risperidone suggests that a significant component of the advantageous effect of risperidone on negative symptoms, compared with haloperidol, is due to a direct effect that cannot be accounted for by the effect of risperidone on positive symptoms and its superior side-effect profile. Although it is possible to analyse studies retrospectively in this way, the best approach is probably to design future clinical trials so that the effects of drugs on negative symptoms are more easily determined than has been the case in the past.

Affective Symptoms↗