• Various aspects of speech and language were compared, using psycholinguistic techniques, in a group of 15 depressed patients and 16 manic patients: lexical diversity, syntactical complexity, syntactical elements, and content analysis. Contrary to anticipation, the manic patients did not show more varied word choice or complexity of sentence structure than the depressives. In particular, they did not differ significantly in type-token ratio. The greatest difference was in syntactical elements, with manics using more action verbs, adjectives, and concrete nouns, while the depressed patients used more state of being verbs, modifying adverbs, first-person pronouns, and personal pronouns. When compared by content analysis, the manics used more words reflecting a concern with power and achievement. These results imply that depressive speech tends to be more vague and qualified and to show considerable self-preoccupation, while manic speech tends to be colorful and concrete and to show more concern with things than with people.
Andreasen NJC, Pfohl B. Linguistic Analysis of Speech in Affective Disorders. Arch Gen Psychiatry. 1976;33(11):1361-1367. doi:10.1001/archpsyc.1976.01770110089009