Metaphor Processing Dysfunctions in Schizophrenia Patients With and Without Substance Use Disorders.

Ewa Karabanowicz,Monika Folkierska-Żukowska,Karol Karasiewicz,Monika Mak,Andrzej Sokołowski,Ernest Tyburski,Wioletta Radziwiłłowicz

doi:10.3389/fpsyt.2020.00331

Abstract

BackgroundPatients with schizophrenia have difficulties comprehending metaphors, which significantly impedes communication. However, this topic has not been thoroughly studied in people with a dual diagnosis. On this basis, we formulated two research aims: a) to compare the ability to comprehend metaphors in schizophrenia patients without (SZ) and with substance use disorder (SZ-SUD) and b) to determine the relationship between the processing of metaphorical content and the severity of psychopathological symptoms in both clinical groups.MethodsA total of 40 individuals with SZ and 40 individuals with SZ-SUD took part in the study. The control group was composed of 40 individuals without a psychiatric or neurological diagnosis. Four subtests from the Right Hemisphere Language Battery (Picture Metaphor Test, Written Metaphor Test, Picture Metaphor Explanation Test, Written Metaphor Explanation Test) were used to measure the ability to understand and explain metaphors.ResultsBoth groups of individuals with schizophrenia (SZ and SZ-SUD) scored lower than individuals from the control group on all tests of metaphor processing. However, no differences were observed between the two clinical groups. SZ-SUD patients had better results for Picture Metaphor Explanation than for Written Metaphor Explanation. Negative symptoms were found to be significant predictors of difficulties with understanding and explaining metaphors.ConclusionIndividuals with schizophrenia, regardless of their substance use disorder (SUD) status, exhibit impaired metaphorical content processing. SUD in schizophrenia is not associated with significant impairments in understanding and explaining metaphorical content. Moreover, impairments in processing metaphorical content are associated with more severe negative symptoms of schizophrenia.

Highlights

Metaphors are a form of non-literal language use
A total of 120 individuals took part in the study: 40 individuals diagnosed with paranoid schizophrenia (SZ; aged 19–58); 40 with paranoid schizophrenia and substance use disorder (SZSUD; aged 19–55); and 40 healthy controls (HC; aged 19–58) matched in terms of age, gender, and education
schizophrenia and substance use disorder (SZ-SUD) patients were selected based on medical history, consultation with psychiatrists, and a clinical interview based on the ICD-10 with the patient which was performed before the study

Summary

Introduction

Metaphors are a form of non-literal language use. They are a special type of figurative expression whose meaning is generated by the semantic overlap between two distant concepts. Conventional metaphors are used in everyday language and are embedded in the associated culture [e.g., Marriage is a jail; [1]] They are stored in one's memory and processing them requires recollection of meaning rather than construction of meaning. Patients with schizophrenia have difficulties comprehending metaphors, which significantly impedes communication This topic has not been thoroughly studied in people with a dual diagnosis. On this basis, we formulated two research aims: a) to compare the ability to comprehend metaphors in schizophrenia patients without (SZ) and with substance use disorder (SZ-SUD) and b) to determine the relationship between the processing of metaphorical content and the severity of psychopathological symptoms in both clinical groups

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Methods

Results

Discussion

Conclusion