Unhealthy lifestyles exacerbate risk factors for cardiovascular disease, which may be closely associated with psychosocial stress. Stress is the term used to define the body's physiological and/or psychological reaction to circumstances that require behavioral adjustment. The Japanese Society of Psychosomatic Medicine defines "psychosomatic illness" as any physical condition with organic or functional damage affected by psychosocial factors in the process of its onset or development. Psychosomatic medicine, or biopsychosocial medicine, encompasses all aspects of the interrelationships between the biological, psychological, social, and behavioral factors of health and illness, and is not limited to mind and body connections in humans. Metabolic syndrome is a combination of metabolic risk factors associated with insulin resistance and an increased risk of coronary artery disease. Particularly in developed countries, increases of metabolic syndrome and mental health problems such as depression are serious social issues by themselves; and their relationship is also important. Our recent studies have addressed the association of metabolic syndrome with depression. In other studies, exercise has recently been reported as useful treatment for both metabolic syndrome and depression. Such recent studies strengthen the importance of the relationship between life-related diseases and mental health.
The environmental change by the earthquake, tsunami and nuclear plant accident in the east of Japan has an influence on not only the mental health but also the physical health through autonomic nervous system. "The psychophysiological stress (trauma) care" is a method of the self-care to improve a mind-body stress reaction by one-self. This is one of the mind-body interventions that can improve various mental and physical symptoms by restoring autonomic nerve system balance even if under the situation without medical facilities and medicine. This self-care approach is based on "an educational model". This method revives stress responses of autonomic nervous system caused by disaster, using self-control techniques focusing to cognition, behavior and nutrition.
Biofeedback is defined as a group of non-pharmacological therapeutic procedures that use electronic instruments to measure, process, and provide information to patients regarding their neuromuscular and autonomic nervous system activity in the form of analogue (or binary) and visual (or auditory) signals. A recent technical improvement in biological monitoring and data processing makes biofeedback more reliable and comfortable to apply for the treatment of medical disorders. For example, our group developed an easy-to-use blood pressure biofeedback system in combination with a continuous blood pressure monitoring device and a personal computer, and reported that the system was useful in treating several forms of hypertension, including essential hypertension. As reported previously (Hypertens Res 26: 37-46, 2003), our practical experience suggests that the following points need to be thoroughly addressed in future biofeedback studies: 1. The characteristics of the therapists (e.g., age, gender, and profession) as well as the patients' motivation and suggestibility should be assessed in order to study the therapist-patient relationship. 2. Mood states (especially anxiety, tension, and depression) should be monitored with physiological variables as treatment outcomes. 3. Biofeedback treatment and pre- and posttreatment assessment should be performed by "blinded" observers who are independent of the study. 4. It should also be documented whether subjects are blinded to the information on their group assignment. 5. Patient "habituation" and "regression to the mean" in biofeedback sessions and blood pressure measurements should be assessed and controlled. These points would help to clarify the framework of biofeedback, as well as the psychological and physiological mechanisms of biofeedback treatment.
Biofeedback developed initially from discussions on learning theories in psychology. It was originally thought that autonomic responses were learned by classical conditioning only. However, Neal E. Miller (1969) indicated that acceleration and deceleration of heart rates in rats could be learned by operant conditioning by applying stimulation to the brain when the target change in heart rate took place. Furthermore, Joe Kamiya (1969) showed that subjects could discriminate the state of alpha wave and control the wave using a device that presented a sound when alpha waves were detected. We cannot generally regulate our autonomic responses or activities of the central nervous system; however, these studies indicate that involuntary responses could be controlled using techniques in which information on physiological states is given to the subject. These discussions and methodologies have led to the development of biofeedback. The essential aspect of biofeedback is the process in which information on the physiological states of an organism is returned to the organism itself. It is possible to consider that the information on physiological states includes various contents, such as behavior, posture, changes in body weight, changes in facial expression and complexion, and results of medical checkups. Such a wide definition of biofeedback will expand the region of biofeedback research and contribute to development of this research.