- A-temporality
- Abandonment
- Abreaction
- Absent-presence
- Abstinence
- Abstinence (rule of)
- Accident proneness
- Accomplice
- Accordion phenomenon
- Acculturation
- Acculturation gap
- Act
- Act of faith
- Acting
- Acting in
- Acting out
- Action
- Action language
- Active defensive primal repression
- Active technique
- Activity/ passivity
- Actual
- Actual neurosis
- Actualization
- Adaptation
- Adaptive perspective
- Addiction
- Addiction to near-death
- addictive love
- Adhesive equation
- Adhesive identity
- Adhesive pseudo-object relations
- Adhesiveness of the libido
- Adolescence
- Adolescent detachment
- Adolescent identity crisis
- Adoption trauma
- Adult development
- Affect
- Affect intolerance
- Affect processing
- Affect regulation
- Affection (or tenderness)
- Affectionate and sensual currents
- Affectionate attachment
- Affectionate transference
- Affective core
- Affective monitoring
- Affective organ language