Psychodynamic psychotherapy (or psychodynamic therapy) and psychoanalytic psychotherapy (or psychoanalytic therapy) are two categories of psychological therapies. Their main purpose is to reveal the unconscious content of a client's psyche in an effort to alleviate psychic tension, which is inner conflict within the mind that was created in a situation of extreme stress or emotional hardship, often in the state of distress. The terms "psychoanalytic psychotherapy" and "psychodynamic psychotherapy" are often used interchangeably, but a distinction can be made in practice: though psychodynamic psychotherapy largely relies on psychoanalytical theory, it employs substantially shorter treatment periods than traditional psychoanalytical therapies. Studies on the specific practice of psychodynamic psychotherapy suggest that it is evidence-based. Long-term psychoanalytic psychotherapy may offer small but statistically significant benefits over other therapies for complex mental disorders, though findings are limited by study differences and methodology.

Psychodynamic psychotherapy relies on the interpersonal relationship between client and therapist more than other forms of depth psychology. They must have a strong relationship built heavily on trust. In terms of approach, this form of therapy uses psychoanalysis adapted to a less intensive style of working, usually at a frequency of once or twice per week, often the same frequency as many other therapies. The techniques draw on the theories of Freud, Melanie Klein, and the object relations theory proponents, such as Donald Winnicott, Harry Guntrip, and Wilfred Bion. Some psychodynamic therapists also draw on Carl Jung, Jacques Lacan, or Robert Langs. It is a focus that has been used in individual psychotherapy, group psychotherapy, family therapy, and to understand and work with institutional and organizational contexts. In psychiatry, it has been used for adjustment disorders and post-traumatic stress disorder (PTSD), but more often for personality disorders.

The principles of psychodynamics were introduced in the 1874 publication Lectures on Physiology by German physician and physiologist Ernst Wilhelm von Brücke. Von Brücke, taking a cue from thermodynamics, suggested all living organisms are energy systems, governed by the principle of energy conservation. During the same year, von Brücke was supervisor to first-year medical student Sigmund Freud at the University of Vienna. Freud later adopted this new construct of "dynamic" physiology to aid in his own conceptualization of the human psyche. Later, both the concept and application of psychodynamics were further developed by the likes of Carl Jung, Alfred Adler, Otto Rank, and Melanie Klein. Psychodynamic therapy has evolved from psychoanalytic theory, with some later modifications in the therapeutic practice experienced since the mid-20th century.

Most psychodynamic approaches are centered on the concept that some maladaptive functioning is in play and that this maladaptation is, at least in part, unconscious. The presumed maladaptation develops early in life and eventually causes daily difficulties. Psychodynamic therapies focus on revealing and resolving these unconscious conflicts driving their symptoms. The therapist takes a more interpretive and much less directive role.

Major techniques used by psychodynamic therapists include:

The first type of resistance is conscious resistance, where the client is deliberate about not communicating the information needed because of distrust in the system, therapist, shame, or rejection of the interpreter.

The second, repression resistance, or ego resistance, is used by the client to keep unacceptable thoughts, feelings, actions, and/or impulses in the unconscious. This could be done by the patient blocking thoughts and communications during free associations and not remembering events.

The third, id resistance, is unlike the other two because it arises from the unconscious and is driven by id impulses. It resists change or treatment to further repeat the trauma in different situations, known as repetition compulsion. Additionally, there may be transference of views, feelings, and/or wishes of the patient onto the analyst, often the therapist, that were initially directed towards other impactful individuals in the patient's life. This is frequently people in early childhood, such as parents, siblings, or other important people. Addressing these projected views is hoped to help the patient reexperience, address, and analyze the effects and resolve the current distress it could be causing. As in some psychoanalytic approaches, the therapeutic relationship is seen as a key means to understanding and working through the relational difficulties which the client has suffered in life.