Clinical descriptions and language analyses are presented of four patients with affective disorders. The characteristics of speech are discussed which were most consistently observed in each syndrome as based on a study of 40 patients of which the four described in detail are representative. The observations are outlined in the following table:One atypical case, presenting a mixed state of the manic-depressive group, is described in which pressure of activity and speech was associated with depression, apprehension, bewilderment and self-accusations. Speech analysis showed vigorous articulatory movements; wide pitch range; gliding pitch changes associated with accents; fast speech tempo; infrequent, prosodic pauses; pharyngeal resonance; absence of glottal rasping; colloquial level of style; extreme and frequent degree concepts; rich syntactic elaboration with diversified syntactic techniques; quick initiation of responses; lengthy responses dealing with single theme but disordered in sequence.