[Health psychology: a key to understand therapeutic adherence]

The lack of compliance with treatment is a public health problem that affects the patient's quality of life, avoids an objective assessment of therapeutic effectiveness and may even cause death. Non compliance can be considered an one-dimensional problem that only depends of patients's responsibility. However, Health Psychology has generated theoretical models that allow the prediction and understanding of therapeutic compliance. It also expands the responsibility to other agents involved in the therapeutic process, specifically health care providers and health systems.