Developmental considerations in the concept of affective illness.

A spectrum exists from change, to crisis, to turmoil, and, at times, to illness at watersheds in the life cycle. Affective experience can be a mobilizing factor and emotional catalyst in the growth experience or a devastating psychotic mood disturbance when predisposing life events and genetic disposition are operational. This paper reviews the dynamics of biologic systems, chronobiology, and time-related transitions of the developmental experience. The relationship of a developmental time clock to affective phenomenology and clinical affective disorder is discussed and presented in two case vignettes. Developmental theory and the interface between life events, stress, and affective illness are reviewed and a concept of development as a sequence of affective cycles is presented.