title: Over-adaptation and heart rate variability in Japanese high school girls.
abstract: BACKGROUND
  In the field of educational psychology in Japan, a model of "over-adaptation" has been applied to conceptualize the personality of students who are vulnerable to external stressors and prone to developing psychiatric problems. However, the influence of over-adaptation on physiological functions in adolescents is still largely unknown. Therefore, the present study aimed to investigate the association between an over-adapted tendency and autonomic nervous system activities in high school girls.
  
  
  METHODS
  Circadian profiles of cardiac autonomic nervous system activities in 47 normal high school girls were evaluated using time-domain measures of heart rate variability (HRV) taken from 24-h ambulatory electrocardiogram recordings, and their relation to an over-adaptation scale composed of 5 subscales was evaluated.
  
  
  RESULTS
  A significant increase in RMSSD (root mean square of successive difference of normal-to-normal beat intervals) during daytime (09:00-14:00) was observed in students who scored high on the sum of the over-adaptation subscales (n=6). Two of the over-adaptation subscales, namely, "self-restraint" and "self-insufficiency", were positively correlated with time-domain measures.
  
  
  CONCLUSIONS
  Parasympathetic activity in over-adapted students was elevated during school, and this autonomic response was suggested to be linked to over-adaptation subscales related to repressed emotions in over-adapted students. Thus, in over-adapted students, repressing emotions appears to be a style of coping, and may lead to a quiet, emotionally stable life in school, which in turn may result in parasympathetic activation.
authors.affiliation: Department of Maternity Child Nursing, Akita University Graduate School of Medicine and Faculty of Medicine, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Sugawara
authors.forename: Izumi
authors.initials: I
authors.lastname: Hiramoto
authors.forename: Hideya
authors.initials: H
authors.lastname: Kodama
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000293:Adolescent; D044466:Asian People / Q000523:psychology*; D015331:Cohort Studies; D004562:Electrocardiography / Q000379:methods / Q000523:psychology; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D013334:Students / Q000523:psychology*