Increase in Salivary Alpha-Amylase Levels among Non-Attending Junior High School Students Diagnosed with Social Anxiety Disorder

Abstract

Purpose: Several studies have demonstrated that the measurement of salivary alpha-amylase (sAA) levels is a useful tool for evaluating the autonomic nervous system. Psychosocial stress increases the release of sAA as a useful marker for autonomic nervous system (ANS). To our knowledge, although some studies have evaluated sAA levels under psychosocial stress, no studies have investigated the changes in sAA activity that occur in junior high school students who are not attending school due to social anxiety disorder (SAD). We aimed to investigate the relationship between the sAA levels and psychiatric states of such patients. Methods: The study subjects consisted of SAD patients (n = 39) and healthy controls (n = 57). We used a portable hand-held monitor to measure the level of sAA and State-Trait Anxiety Index (STAI) to evaluate the psychiatric state. Results: The patients’ sAA activity was significantly higher than that of the controls (n = 57) ( p < 0.001). Significant differences in heart rate (HR) (76.10 ± 11.96 vs. 68.69 ± 10.61, respectively, p < 0.01) and STAI scores (both the STAI-State and STAI-Trait scores) (49.35 ± 10.57 vs. 41.24 ± 8.59, respectively, p < 0.01; 55.69 ± 10.44 vs. 45.61 ± 9.36, respectively, p < 0.001) were detected between the patients and healthy controls. Conclusions: These results indicated that junior high school students with SAD exhibit a higher state of anxiety and high autonomic activity, probably due to changes in the sympathetic nervous system. As a result, junior high school students with SAD are expected to exhibit high levels of sAA accompanied by anxiety symptoms.