The concept of biopsychosocial model is much advanced than the biomedical model and is currently being used in the field of medicine, nursing, sociology, health psychology, psychiatry, clinical social work and chiropractic medicine.
According to the biomedical model of health, physical illness is caused by a particular "pathogen" or disease causing organism (Curtis, 2000). The pathogens cause the disease because of which some physical changes occur within the body. The causative factors are not only organisms but some chemical imbalances and genetic predisposition. According to the biopsychosocial model, illness is caused due to an interplay of a multitude of factors and that most of the times illness results from an interplay of biological factors like pathogens, psychological factors like beliefs and behaviors and social factors like economic status and employment. This model of health was developed by Engel in the 1970s. The psycho aspects of health which this model proposed were cognitions like expectations of health, certain emotions like fear of treatment and important health-related behaviors like consumption of alcohol, smoking, diet and exercise (Curtis, 2000). Emotional turmoil, lack of self-control and negative thinking have been incriminated in the development of disease. The social aspects of health which this model proposed were social drinking, peer group pressure and expectations, social values of health, ethnicity, parental pressure and expectations and social class. The biopsychosocial model of health is basically based on the social cognitive theory (Curtis, 2000).
The biomedical model perceives illness as beyond the control of the individual and thus individuals are not responsible for the illness. Here patients are regarded as victims of external force that causes changes in the internal aspects of the patients. But the biopsychosocial model perceives illness as a combination of