Psychoanalysis is a psychiatric treatment method used to treat many forms of mental illness that have no organic cause, such as neurosis and antisocial personality disorder among others. It was developed as a technique by Sigmund Freud in the early 20th century, and was further developed until by the 1960s it was the primary form of psychiatric treatment for lucid patients. However, the development of many anti-psychotics and anti-depressants during the 1970s led to a decline in the use of the technique and, by the 1990s, it's use was fairly uncommon among physicians. However, since that time a better understanding of the side effects of mild cases of depression and other mental illnesses has led to a resurgence of its use.
The basic technique is more than adequately illustrated and explained in both Broken and Baggage as Darryl Nolan attempts individual therapy with Gregory House. The therapist answers open ended questions designed to draw out the concerns of the patient. As can be seen, this requires a great deal of trust by the patient in the therapist, and an initial lack of trust, although common, is fatal to the technique if it persists.
In addition, as House did, patients often try to deflect therapy back on the physician, and intelligent ones like House realize when the physician is deflecting back. It is not uncommon for the therapist to remind the patient on the purpose of the technique - just to get them to talk about things that are important to them.