Relationship between brain function and stress has been studied in recent years using some new equipment which declare the brain function in objective manner. This special issue includes four papers about; (1) non-invasive neuroimaging techniques, (2) chronic stress and decision-making, (3) brain-gut interactions and (4) exercise as a treatment of depression.
Each non-invasive neuroimaging technique has its own inherent limitations resulting from temporal and spatial inaccuracies due to the nature of information that can be measured. Recent advances in non-invasive brain imaging techniques enable us to choose a set of the most appropriate imaging modalities depending on the purpose of the study from several possible candidates. In this paper, I briefly summarize the characteristics of the major brain imaging techniques, namely, electroencephalography (EEG), magnetoencephalography (MEG), functional magnetic resonance imaging (fMRI) and near-infrared spectroscopy (NIRS). Also, some examples of using these neuroimaging techniques to visualize brain activities related to subjective sensation of mental fatigue are presented to show potential application of the techniques for the quantitative evaluation of stress and fatigue.
Chronic stress affects decision-making, especially shifts dominant modes of decision-making from goal-directed action to habit action. Animal studies have revealed that atrophy of the prelimbic and inflalimbic prefrontal cortex and dorsomedial striatum as well as hypertrophy of the dorsolateral striatum by chronic stress mediates the alteration of decision-making. We expanded this finding to humans by a neuroimaging study and further suggested that chronic stress causes dysfunctional regulation of physiological responses by the brain. Another study using functional and structural neuroimaging replicated these findings and further showed that stress-caused alterations of decision-making and the structure and function of the brain can be reversible once individuals are released from stress. Stress-induced habit action might mediate the association between chronic stress and diseases by leading to unhealthy behaviors such as over-consumption of tobacco and alcohol, less physical activity, and addition to drugs. Further studies are needed to clarify detailed mechanisms by which chronic stress causes alterations of the brain and decision-making, and possibility of effective preventions for maladaptive influences on health.
Irritable bowel syndrome (IBS) is a representative stress-related disorder. Major pathophysiological feature of IBS is brain-gut interactions, which is typically manifested by visceral perception and altered stress response. Visceral pain signal is originated from the primary afferent neuron whose cell body is located in the dorsal root ganglia. In the lamina I of the posterior horn of the spinal cord, the primary afferent neuron switches the pain signal via synapse to the second order neuron. The axon of the lamina I neuron ascends the spinothalamic and spinoreticular tract. The pain signal is spread to the insula, anterior cingulate cortex, and the prefrontal cortices via the thalamus. These are the specific pathway from the gut. The lamina I neuron switches its signal to the amygdala and hypothalamus via parabrachial nucleus. Thus, strong intensity of pain signal and/or low pain threshold cause (s) visceral pain as well as stress response including negative emotion. Clarification of the IBS pathophysiology probably provides keys to disclose the synthetic mechanism of negative emotion. Further research is warranted to solve the processing of normal visceral perception as well as pathophysiology in the central nervous system in IBS.
The number of depressive patients is increasing in Japan. Depression is commonly treated with antidepressants and/or psychotherapy, the potential use of exercise as an alternative or complementary treatment for depression has recently received considerable attention. There are a number of physiological reasons why exercise may improve depression. The scientific evidence from prospective cohort studies supports the overall conclusion that regular participation in exercise is associated with reduced depressive symptoms. The results of randomized controlled trials indicate that participation in exercise programs reduces depressive symptoms in people diagnosed as depressed, healthy adults, and medical patients without psychiatric disorders. The results of two meta-analyses have demonstrated that effect sizes in intervention studies for depressed people are large. However, the evidence is not always consistent. Despite some inconsistencies in research findings, in the UK, guidelines which include exercise as a management strategy for depression; NICE guidelines have recommended structured, supervised exercise programs for mild to moderate depression. Further studies that are methodologically robust are required to determine more accurately the effect of exercise on depression. Optimal physical activity dose for reducing the depressive symptom should be extensively studied to for the prescription of appropriate exercise to improve mental health.
The purpose of this study was 1) to develop competitive and daily stressor scale for female athletes, and 2) examine the relationship among stressor, stress response and female athlete triad (FAT) syndrome. 300 female athletes completed a set of questionnaires including the competitive stressor scale for female athletes (CSSFA) and the daily stressor scale for female athletes (DSSFA) that were developed in this study, the stress response scale for athletes (SRSA), and questions about FAT. The results of exploratory factor analyses revealed 2-factor solution of the CSSFA and 3-factor solution of the DSSFA. The reliability and validity of the each scale were statistically satisfied. The multiple regression analyses showed that "Harassment and Discrimination" had a significant association with "Physical fatigue". "Competitive performance and environment" had significant associations with "Physical fatigue", "Helplessness", "Distrust of people", and "Depression". "Menstruation" had significant associations with "Physical fatigue", "Irritation and anger", and "Depression". "Maintenance and change in body proportion" had significant associations with "Physical fatigue" and "Irritation and anger". Result of t-test showed that the score of "Menstruation", "Physical fatigue" and "Depression" of FAT group was higher than non-FAT group. The results indicated that the relation among female athletes' stressor, stress response and FAT.
This study aimed to qualitatively examine psychological and behavioral reactions to rheumatoid arthritis (RA) from the appearance of initial symptoms to after definitive diagnosis. Between February 2011 and August 2011, subjects were recruited by introduction from one patient group and four medical institutions (general hospitals). Twenty patients (mean age: 56.5±10.8 years) provided written consent to participate in the study. We conducted semi-structured interviews with the patients, asking about thoughts, feelings, and conditions from the appearance of initial symptoms to after definitive diagnosis. In order to qualitatively examine patients' psychological and behavioral reactions, we conducted summarizing content analysis. At onset, patients experienced the appearance as well as disappearance of pain. Moreover, patients saw things optimistically. While they mentioned "I don't know what has happened," their only exploratory efforts were to "look up RA in books." At the time of their first visit to a medical institution, patients came to harbor worries and anxieties. They transitioned to consultation behavior, saying, "I'll visit a specialized medical institution." Furthermore, after definitive diagnosis, patients newly came to have emotions and thoughts such as mistrust or a sense of relief regarding doctors and medical professionals, and depression, worry, anxiety, or relief regarding illness.
The objectives of this study were to arrange a brief stress management (STM) program for children and examine its effectiveness. The STM program consisted of teaching children about psychological stress mechanisms and training them in progressive muscle relaxation. In order to assess the effectiveness of the STM program, 64 children were asked to experience 4 scales before and after the program. The scales included a stressor scale, a stress response scale, a stress coping scale, and practical use of STM skills and knowledge scale. The results were as follows: (a) children came to understand psychological stress mechanisms and acquired progressive muscle relaxation in a short time; (b) even after the STM program ended, STM skills and knowledge were still used; (c) all sub-scale scores before and after the STM program showed no difference.
In this study, we examined 1) whether the laughter affects the cognitive appraisal to stressful situations or not, 2) whether the effect is caused by mirth or physical expression, and 3) how the laughter, the cognitive appraisal, and the personalities are related. In the experiment, participants listened to a humorous or neutral auditory stimulus. After that they evaluated the imaginary stressful situations. In this study, there were three experimental conditions. In condition 1, participants listened to the neutral auditory stimulus and they didn't feel mirth. In condition 2, participants listened to the humorous stimulus and they felt mirth. In condition 3, participants listened to the stimulus used in condition 2. Furthermore, they were asked not to laugh. As a result, the laughter didn't affect the cognitive appraisal. However the data have shown that the cognitive appraisal correlated with the personalities differently in each condition. Thus, it is possible that the laughter affects the relationship between the cognitive appraisal and the personalities. We expect that the effect of the laughter will be examined by improved experiments in the future, while focusing on the personalities which seem to have relationship with the cognitive appraisal.
This study examined which psychological factors characterize posttraumatic stress disorder (PTSD) symptoms and depression in students affected by the Great East Japan Earthquake. Specifically, we examined automatic thoughts, negative appraisals of posttraumatic stress symptoms, and posttraumatic growth. We administered an inventory assessing these factors to 289 high school students (139 boys and 150 girls) of Iwate Prefecture who had been affected by the Great East Japan Earthquake. We then performed a discriminant analysis to examine which patterns of these factors predicted PTSD symptoms and depression. Our results suggested that having negative appraisals of posttraumatic stress symptoms and posttraumatic growth predicted PTSD symptoms, while having automatic thoughts and posttraumatic growth predicted depression. The present results can inform the development of preventive approaches; for example, cognitive restructuring would be useful for decreasing students' negative appraisals of their posttraumatic stress symptoms and increasing posttraumatic growth, which would facilitate their recovery from disaster traumas and reduce the likelihood of their developing PTSD.
The transtheoretical model (TTM) regards of health behavior change as progression throughout the five stages: precontemplation, contemplation, preparation, action, and maintenance. Processes of change such as strategies and techniques to enhance the progression among TTM concepts facilitate stage transition. Use of experiential processes (affective and/or cognitive strategies such as seeking information) for behavioral change increase and tend to peak at the precontemplation, contemplation, and preparation stage and then decease. Behavioral processes (behavioral strategies such as a seeking social support) tend to be used most at the action and/or maintenance stage. This study examined relationships between stages and processes of change for effective stress management and with covariance of gender differences in Chinese college students. Effective stress management was defined as any form of healthy activity such as exercising, meditating, relaxing, and seeking social support, which is practiced for at least 20 minutes. Eight hundred and seventy one Chinese college students participated in this paper-pencil survey. Four experiential processes and five behavioral processes peaked in the action or maintenance stages. This study represented an initial but important test of validity of applying processes of change and gender difference to stress management in Chinese college students. Results partially supported its application.
Several complementary and alternative regimens have been developed to encourage relaxation and control stress. Recently, "shinrin-yoku"(walking in a forest and viewing the forest landscapes) has been recognized as a successful relaxation activity. The objective of this study was to evaluate the effectiveness of a "shinrin-yoku" program on stress and relaxation for adolescent girls. Twenty-seven girls, aged 12 to 14 years, participated in a program that included walking in a forest and viewing the forest landscape; performing the same activities in a city area was used as a control experience. Salivary amylase activities, the Mood Inventory, and subjective relaxation were measured. The mean values of salivary amylase activities decreased in the forest and increased in the city. The responses to the Mood Inventory indicated a relaxed mood after walking the forest. In addition, the presence of negative moods in the forest was significantly lower than in the city, and the subjective relaxation level in the forest was significantly higher than in the city. Our results indicated that the forest environment was effective in increasing relaxation and decreasing stress and fatigue. Shinrin-yoku may play a role in improving or maintaining the psychological health of adolescent girls.