Although few today follow him strictly, Sigmund Freud's profound influence upon psychology continues. The work of his followers, especially Jung, Adler, and Erik Erikson more immediately inform psychodynamic therapy.

As everyone knows, libido (sexual energy) is at the center of the Freudian theory of human growth and development. Other personality structures described by Freud have long been part of popular parlance: the id (seeking immediate gratification and acting on the pleasure principle), the ego (the thinking self regulating the id), and the superego (conscience, ideal self, and standards). An individual's response to the dynamic tension between eros (life force) and thanatos (death or destructive force) strongly affects personality.

Freud's stage theory of human development proposes basic personality formation by about age five. Each of the following stages has developmental causes and effects:

1. Oral (birth to about age 2)

2. Anal (about ages 2 to 3)

3. Phallic (about ages 3 to 6)

4. Latency (about 6 to puberty)

5. Genital (puberty to old age)

In contrast to Freud, Carl Jung came to view libido as a generalized psychic energy, not necessarily sexual. From the Jungian psychoanalytic perspective, people instinctually push toward individuation and wholeness as they develop psychologically. Seeking to become one's true self is an endeavor common to humanity. Jungian interpretations focus on a person's present state and potential growth rather than on antecedent causes. Looking to dreams, fantasies, connections between inner and outer realities, and other windows to the unconscious increases awareness and personal growth.