Familiar language in treatment-resistant depression: Effects of deep brain stimulation of the subcallosal cingulate

Communication, specifically the elements crucial for typical social interaction, can be signifi-cantly affected in psychiatric illness, especially depression. Of specific importance to conversa-tional competence are familiar expressions (prefabricated expressions known to the language community) including formulaic expressions (conversational speech formulas and idioms; these are high in nuance) and lexical bundles (fixed linguistic segments that are prevalent in natural-istic conversation; low in nuance). The goals of this study were to examine familiar language production in the naturalistic, conversational speech of individuals with treatment-resistant depression before and after receiving surgical deep brain stimulation of the subcallosal cingu-late white matter pathways and to compare their performance to healthy adults' familiar lan-guage use. Results revealed fewer conversational speech formulas (typically nuanced) produced by those with depression pre-and post-operatively as compared to healthy controls. There was an increase in the production of non-nuanced familiar expressions (largely lexical bundles) and a decrease in nuanced expressions (formulaic expressions) post-operatively when compared to the pre-operative condition for those with depression. These results conform to a recent model that distinguishes three distinct classes of familiar language, based on linguistic and neurological criteria. This study offers a first look at familiar language in depression and provides a foundation for further study into the pragmatic components of communication to help address the often -reported diminished social connectedness experienced by those with depression.