Positive Disintegration
Kazimierz Dabrowski
Little, Brown and Company
The Theory of Positive Disintegration (TPD) by Kazimierz Dąbrowski describes a theory of personality development.

Unlike mainstream psychology, Dąbrowski's theoretical framework views psychological tension and anxiety as necessary for growth. These "disintegrative" processes are therefore seen as "positive," whereas people who fail to go through positive disintegration may remain for their entire lives in a state of "primary integration." Advancing into disintegration and into the higher levels of development is predicated on having developmental potential, including overexcitabilities and above-average reactions to stimuli.

Unlike some other theories of development such as Erikson's stages of psychosocial development, it is not assumed that even a majority of people progress through all levels. TPD is not a theory of stages, and levels do not correlate with age.