A leopard cannot change its spots: A novel pragmatic account of concretism in schizophrenia

Concretism is a well-known feature of schizophrenia, tracing back to the early descriptions of the disease and commonly associated with the literal interpretation of figurative expressions such as proverbs, metaphors, and idioms. However, figurative expressions are not all alike in terms of linguistic and pragmatic processes. Determining if some figurative types are more impaired than others and if the type of task affects the performance constitutes an open issue with implications for the description of the clinical profile and for treatment. We run a fine-grained assessment of figurative language comprehension by comparing 47 patients with schizophrenia and 39 controls in three figurative types (idioms, metaphors, proverbs) presented in two response formats (multiple-choice, verbal-explanation), considering also the role of cognitive and clinical variables and the impact on quality of life. Mixed-effects models analysis revealed that: i) patients performed worse than controls across figurative types and response formats, indicating a diffuse impairment; ii) there is an interplay of figurative type and response format, which makes verbal-explanation of proverbs especially challenging; iii) in patients, problems in figurative language are largely connected with formal thought disorder and global IQ. Moreover, multiple-choice of metaphors was associated with patients' quality of life. This study offers a novel account of concretism, framed in pragmatics and figurative language processing. Adopting this perspective allowed us to describe the nuances of concretism, which areas in the figurative domain are especially challenging for patients and which ones capture differences in functioning, in order to guide intervention programs and integration in society.