Psychodynamic therapies are 'talking therapies' derived from the work of Sigmund Freud in the early 20th Century.
Freud developed a therapy called psychoanalysis.
Freud's original ideas have since been modified to produce many related but different therapies, collectively known as 'psychodynamic' therapies.
Here is an outline of the basics of psychoanalysis.
Freud compared the mind to an iceberg.
Most of the things going on in our minds are in our 'unconscious' so we are not aware of them.
Conflicts going on in the unconscious mind can cause disorders of thought and behaviour.
To treat someone for disturbed behaviour it is necessary to try to find out what unconscious conflicts they may have.
Traumatic events in our childhood are highly likely to cause unconscious conflicts and 'repression' of unpleasant memories that create anxiety disorders later in life.
Freud thought the analysis of dreams was ''the royal road to the unconscious''.
In our dreams we can express our anxieties more freely - but even in our dreams things are disguised in symbols. Freud claimed to be an expert in the interpretation of dreams, publishing a very famous book on the subject in 1900.
Freud said that much of the symbolism in our dreams is to do with sexual or aggressive wishes in our unconscious minds.
In psychoanalysis Freud would have a patient lie on a couch to relax, and he would sit behind them taking notes while they told him about their dreams and childhood memories.
Sometimes Freud used 'free association' - a technique in which the patient would respond to prompts by saying whatever came into their minds. Patients would be encouraged to say anything no matter how bizarre or embarrassing it might seem. Freud would analyse what they said for clues to unconscious conflicts.
Once a traumatic event in the past, or source of conflict had been brought to the surface in this way the patient might feel very emotional. Transference might occur - in which the patient would transfer emotional feelings onto the therapist.
The next stage was 'working through' the previously unconscious source of conflict to come to terms with it and find ways of dealing with it.
Psychoanalysis would be a lengthy process, involving many sessions with the psychoanalyst.
For Freud, just trying to cure a phobia of horses by gradual exposure to horses would not be a 'cure'. The underlying unconscious conflicts would need to be resolved.
In the case of 'little Hans', Freud's only child patient, a phobia of horses was related to Hans' fear of castration - in spite of the fact that Hans had seen an accident involving a horse and been afraid.
Freud's ideas have been very fiercely criticised but he did introduce a new way of dealing with psychological problems - just talking about them!