Add-on fluvoxamine improves primary negative symptoms: Evidence for specificity from response analysis of individual symptoms

Establishing that treatment for negative symptoms improves primary features of schizophrenia rather than similar symptoms of other etiology is an important clinical issue. Primary negative symptoms may also differ among themselves in the propensity to respond to a given treatment. In this study, we examined the response of negative symptoms to add-on fluvoxamine by analyzing discrete symptoms independently and controlling for potential confounding variables. Data from two published controlled studies comparing fluvoxamine to placebo were pooled for the analysis. Eleven of sixteen Scale for the Assessment of Negative Symptoms items tested, including key negative symptoms such as affective flattening and alogia, improved. The improvement was not related to baseline levels of depressive, extrapyramidal, and positive symptoms or to changes in the symptom scores during the study. The findings support the view that fluvoxamine augmentation can improve primary negative symptoms in chronic schizophrenia patients.