Furthering the language hypothesis of alexithymia: An integrated review and meta-analysis. (October 2022) - Lee, Ka Shu
Abstract: Alexithymia, including the inability to identify and express one's own feelings, is a subclinical condition responsible for some of the socioemotional symptoms seen across a range of psychiatric conditions. The language hypothesis of alexithymia posits a language-mediated disruption in the development of discrete emotion concepts from ambiguous affective states, exacerbating the risk of developing alexithymia in language-impaired individuals. To provide a critical evaluation, a systematic review and meta-analysis of 29 empirical studies of language functioning in alexithymia was performed. A modest association was found between alexithymia and multi-domain language deficits ( r = −0.14), including structural language, pragmatics, and propensity to use emotional language. A more theoretically-relevant subsample analysis comparing alexithymia levels in language-impaired and typical individuals revealed larger effects, but a limited number of studies adopted this approach. A synthesis of 11 emotional granularity studies also found an association between alexithymia and reduced emotional granularity ( r = −0.10). Language impairments seem to increase the risk of alexithymia. Heterogeneous samples and methods suggest the need for studies with improved alexithymia assessments. Highlights: This integrated review evaluated the language hypothesis of alexithymia. Meta-analyses showed a small association between language deficits and alexithymia. Alexithymia was modestly related to reduced granularity of emotion concepts. Varied clinical characteristics and methods precluded further subgroup comparisons. A multi-route model of alexithymia is pivotal to elucidate its etiology.