Changes in cognitive function associated with syndrome changes on two five-factor models of the Positive and Negative...

This study aims to examine the association between neuropsychological function and symptom changes over time on two five-factor models, pentagonal (PM) and Van der Gaag (VDG), of the Positive and Negative Syndrome Scale (PANSS) and to determine the added value of these syndrome models for interpreting neuropsychological changes.

Data were collected in a randomized controlled trial comparing second-generation and conventional antipsychotic medications for 108 adult patients diagnosed with schizophrenia and monitored prospectively for 12 months using standard neuropsychological instruments and the PANSS. Random-effects regression was used to estimate the change over time in neuropsychological function and the association of PANSS covariates.

Improvements in positive, negative, and cognitive syndromes were significant predictors of change on nine neuropsychological measures. The neuropsychological function was worsening on five of these measures. The PM model represented the best set of predictors examining positive and negative syndrome covariates, whereas the VDG model consistently represented the best predictors examining cognitive syndrome covariates.

The PM positive and negative syndrome factors and the VDG disorganized thoughts syndrome factor are differentially associated with changes in neuropsychological function over time. Clinical investigators may want to target their use of these factors from the PANSS according to the outcome variables being measured.