Comment on “Semantic memory impairment across the schizophrenia continuum: a meta-analysis of category fluency performance” by Tan et al.

Abstract

I read with great interest the study by Tan et al. (2020) who conducted a meta-analysis of semantic fluency in people across the psychosis continuum. Among other analyses, the authors provide the first meta-analysis of clustering and switching on semantic fluency in patients with chronic schizophrenia, reporting that patients display significantly smaller “mean cluster sizes” compared to healthy subjects. I argue that there are serious concerns about the compatibility of the clustering data used in the meta-analysis.