Joseph Wolpe, possibly influenced by the work of Mary Cover Jones, created a technique called systematic desensitization to treat South African soldiers suffering from what is now known as post-traumatic stress disorder. Combining gradual stepping-up or -down of an anxiety-producing stimulus with a modified form of Edmund Jacobson's muscle relaxation techniques, Wolpe's treatment became the gold standard in treating acute anxiety disorders for more than 50 years.

Gestalt therapy focuses on the idea that each person is best understood against the background of their relationships with other people, ideas, and even their own past and expected future selves. Hallmarks of the gestalt technique include the following: the empty chair technique, the paradox of change, and the recognition that all clients wish to be psychologically healthy. 

In transactional analysis, the person is often described as reliant upon ritualistic games. These games are defined as a series of rule-bound transactions between two or more people that are directed towards an end. The goal of therapy is often seen as getting people to change the games that they play by coming to a higher awareness of their own end goals in life. Ultimately, the person is expected to be able to objectively view their role in the world they live in.

Operant conditioning as a therapeutic technique covers a wide range of possible therapeutic objectives. Operant condition uses a common strategy consisting of reward/punishment mechanisms that reinforce desired behavior and eliminate or reduce undesired behavior. 

During the Dark Ages, people assumed that mental illnesses were caused by demons and evil spirits, which led them to treat psychological patients very cruelly and try to cure them through beatings and other tortuous methods. The Enlightenment led to better conditions for people in mental institutions, and Dorothea Dix and Pinel advocated for better conditions in the 19th century. Some Ancient Greeks, such as Galen, were some of the first to believe that psychological disorders were caused biologically.

Flooding, also known as Immersion Therapy or Prolonged Exposure Therapy, refers to the process of exposing patients to the stimulus or situation that they fear (sometimes, even just by asking the patient to imagine that experience) while explaining or demonstrating that they are in no danger, and that their fear is irrational.

The Cognitive Behavioral model creates a platform for therapy. It encompasses the idea that thoughts lead to emotions and by changing cognition, one can change emotions. Cognitive Behavioral Therapy focuses on replacing negative behaviors and thought-patterns with action, as opposed to focusing on the underlying causes of those behaviors and thought-patterns.

Carl Jung had a generally compassionate attitude towards the mentally ill, who had traditionally been punished and mistreated by the societies they inhabited, especially with the development of industrial society. He believed that the mentally were labelled by society as disturbed due to the fact that they may have stories, beliefs, or attitudes that society as a whole rejects. This could be a number of things-people who are not Christian, who believe in the paranormal, or who have customs and practices that aren't acceptable. He thought the key to healing the mentally ill was through dream analysis and giving an attentive ear to their personal stories that have been suppressed.

"Trephining" is the name for an old treatment of mental illnesses in which doctors made holes in the afflicted person's skull. This treatment was popular in the Middle Ages, and although by modern standards it is considered cruel and ineffective, at the time there was little alternatives. Also mental illness was seen as the intervention of demonic forces, which did little to promote scientific thinking to come up with an effective cure.