The cognitive approach to treating mental illness is designed to find maladaptive and harmful thought patterns and to replace them with healthier ones. This is the most effective in treating less extreme disorders, where ruminating or negative thought patterns may be causing a lot of the suffering. For instance, a person with low self-worth may constantly think people are attacking them personally, but a cognitive therapist may have the patient reframe their thinking so that they don't take everything personally. This encourages the patient to become more holistic in their thinking and stop propagating bad thoughts about themselves.

The point of view taken towards mentally ill people in the Middle Ages was deeply religous. As such, they were seen as people possessed by demonic spirits who could be treated through exorcism or a process called trephining. In trephining, one made holes in the skull, which were supposed to allow the evil spirits to escape. Other mentally ill people were persecuted and sent to jail. Some observers of the time, mainly philosophers, began to hint at biological explanations for mental illness but this did not become a prominent point of view until much later on.

Tertiary prevention is preventing an illness from getting worse. This kind of prevention is used when the illness is permanent and/or chronic. An example would be an alcoholic who, already having quit alcoholic, keeps attending Alcoholics Anonymous meetings since this stabilizes them in periods during which they may be tempted to drink alcohol again.

The main focus of existential therapy is helping a patient carve out their own meaning in life. This therapy was popularized by Victor Frankl who survived the Nazi concentration camps and wrote Man's Search For Meaning. His main reasoning was that life was full of suffering, and he experienced life's worst sufferings during the concentration camp, but meaning must be found from it. For instance, although there were many cruel guards in the camp, he came to profoundly appreciate the kindness of some who treated him well. He found meaning in his situation, which was that human kindness can be found even in the most hostile of places.

The ultimate aim of existential therapy is to help patients do the same in their circumstances: find meaning from their suffering as well as a general purpose in their life to fulfill.

Because alcoholism is a disease with genetic components, the children of alcoholics are especially at risk for developing the disease in the future. Prevention strategies directed specifically toward at-risk populations are categorized as secondary prevention.

The diathesis-stress model posits that although a person may be genetically predisposed to suffer from a mental disorder; its onset may be triggered by stress. For instance, a person who is genetically disposed to schizophrenia may only ever start to experience symptoms after a significantly stressful event. Otherwise, they may never suffer from the disorder their entire lives.

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.