This article explores the role of affect in the disorganized language and thought that can manifest itself in bipolar disorder. Bipolar disorder, or as it was previously known, manic-depressive illness, can produce psychotic language and thought in its more extreme forms. During the production of discourse in bipolar disorder, there is a strong correlation between the underlying affective state, i.e., depression, euthymia, hypomania, and mania, and linguistic and cognitive performance. A psycholinguistic model of the dynamics between language, thought, and affect in bipolar disorder based on McNeill’s (1992, 2000) concept of a “Growth Point” is proposed. In particular, the poetic structural phases of discourse production in bipolar disorder, which vary according to the underlying affective state, provide a phenomenological bridge between the psychotic discourse of mania and normal language production.