History of physical health psychology

Psychological factors in health had been studied since the early 20th century by disciplines such as psychosomatic medicine and later behavioral medicine, but these were primarily branches of medicine, not psychology. Health psychology began to emerge as a distinct discipline of psychology in the United States in the 1970s. In the mid-20th century there was a growing understanding in medicine of the effect of behavior on health. For example, the Alameda County Study which began in the 1960s showed that people who ate regular meals (e.g. breakfast), maintained a healthy weight, received adequate sleep, did not smoke, drank little alcohol and exercise regularly were in better health and lived longer. At the same time, there was a growing realization of the importance of good communication skills in medical consultations. In addition, psychologists and other scientists were discovering relationships between psychological processes and physiological ones. These included the impact of stress on the cardiovascular and immune systems of the body, and the early finding that the functioning of the immune system could be altered by learning.

Psychologists had been working in medical settings for some years previously in several countries such as the UK (sometimes termed medical psychology). However it was a small field, primarily working with adjustment to illness, with psychological factors usually as (often emotional) reactions to illness. In 1969, William Schofield prepared a report for the American Psychological Association entitled The Role of Psychology in the Delivery of Health Services. While there were exceptions, he found that the psychological research of the time frequently saw mental health and physical health as entirely separate, and devoted very little attention to psychology's impact upon physical health. Of the psychologists working at the time, few were involved with this area, and he proposed that new forms of education and training for future psychologists would be needed. The APA reacted in 1973 by setting up a task force to consider how psychologists could help people to manage their health behaviours, as well as to better manage physical health problems and train healthcare staff to work most effectively with patients.

This set in train a series of events that led in 1977 to the formation of a division of the APA dedicated to health psychology, led by Joseph Matarazzo. At its first conference, Matarazzo gave a speech often seen as a foundation of health psychology, in which he defined the new field as "Health psychology is the aggregate of the specific educational, scientific and professional contributions of the discipline of psychology to the promotion and maintenance of health, the prevention and treatment of illness, the identification of diagnostic and etiologic correlates of health, illness and related dysfunction, and the analysis and improvement of the healthcare system and health policy formation". In the 1980s, similar organisations were set up in the UK as the British Psychological Society's Division of Health Psychology in 1986, and the European Health Psychology Society that same year. Similar organizations developed in other countries such as Australia and Japan. Training programs were set up in these countries, usually training health psychologists at graduate level, and in the United States, at postdoctoral level after completing a doctoral degree in clinical psychology such as the PsyD or PhD. In addition, PhDs began to be awarded in health psychology. Today, health psychology is one of the most popular courses in undergraduate psychology degrees, as a choice for Masters degrees such as MSc, and as a career choice in psychology.

In hindsight, the emergence of Health Psychology could have been triggered by many different factors, such as the following:
 * Emergence of epidemiological evidence demonstrating the important relationship between  health and behaviour.
 * Behavioural sciences were added to medical school’s curriculum, and were often taught by psychologists.
 * Health professionals began to receive training in communication skills, with the initial aim of improving patient satisfaction and adherence to medical treatment.
 * Primary care became an emphasis for Clinical Psychology and interventions based on psychological theory were often applied.
 * Behaviour modification and therapy based on theoretically based models demonstrated they could change behaviours and be useful in clinical populations.
 * An increased understanding of the interaction between psychological and physiological factors led to the emergence of Psychophysiology and Psychoneuroimmunology (PNI).
 * The health domain was frequently used by social psychologists for testing theoretical models, such as the links between beliefs, attitudes and behaviour
 * In the early 1980s the diagnosis of AIDS/HIV led to and increase in funding for behavioural research and a focus on behaviour change.

In the United Kingdom, the British Psychological Society’s reconsideration of the role of the Medical Section, prompted the emergence of Health Psychology as a distinct field. It was argued by Marie Johnston and John Weinman in a letter to the 'BPS Bulletin' that there was a great need for a Health Psychology Section, and in December 1986 the section was established at the BPS London Conference, with Marie Johnston as chair. At the Annual BPS Conference in 1993 a review of ‘Current Trends in Health Psychology’ was invited,  and a definition of Health Psychology as ‘the study of psychological and behavioural processes in health, illness and healthcare’ was proposed. The Health Psychology Section became a Special Group in 1993 and was awarded Divisional Status within the UK  in 1997. This meant that the individual training needs and professional practice of Health Psychologists were recognised, and members were able to obtain chartered status with the BPS. The BPS went on to regulate training and practice in Health Psychology until the regulation of professional standards and qualifications was taken over by statutory registration with the Health Professions Council in 2010.