The number of child maltreatment reports in Japan quadrupled over the last decade (Ministry of Health Labour and Welfare, 2021). Among various effects of such maltreatment, social dysfunction has been found to be one of the major sequelae of exposure to child maltreatment (Jenny & Isaac, 2006; Kessler et al., 1997; Nelson et al., 2007). However, findings on specific behavioral expressions of social problems in people with child maltreatment history are not consistent and include both over-engagement, such as aggressive/disruptive behaviors, violent crimes, and sexualized behaviors, and disengagement, i.e. social withdrawal, indicating opposite effects of early life experiences on their behaviors. This study investigates the oxytocin (OT) system, suggesting that the OT plays an important role that link child maltreatment and social functioning since both are known to effect the processes of social cognition and stress coping. Thus, this study aims to examine the effects of child maltreatment on the OT by incorporating a more detailed and comprehensive assessment of the child maltreatment experience to gain a deeper understanding of the mechanism. First, a literature review on child maltreatment and OT was conducted to identify the gap in research methodology and findings. Then, Empirical Study 1 examined the validity of the Japanese version of Childhood Trauma Questionnaire (CTQ-J), in which adolescents in the institutionalized group (N=31) and those in the community group (N=46) completed a questionnaire packet and their scores on CTQ-J were compared to their childhood welfare records. Results showed that the total score as well as the scores of the five subscales of CTQ-J was able to discriminate people with documented experience of any maltreatment and five types of maltreatment, i.e., emotional abuse, physical abuse, sexual abuse, emotional neglect, and physical neglect, respectively. Empirical Study 2 measured salivary oxytocin concentrations of both institutionalized and community groups by enzyme linked immunosorbent assay. Results revealed that physical abuse was associated with higher OT, while emotional neglect showed an inverse relationship to OT. A U-shaped association between the number of maltreatment types and OT was identified. As the number of maltreatment types increased from zero to one, OT declined, but as the number increased from one maltreatment type to 2 or 3 types and to 4 or 5 types, OT also increased. The results indicated that the effect of child maltreatment on salivary OT concentrations varied according to the types of maltreatment experienced by each individual. While lower OT levels may lead individuals to disengage from interpersonal relationships, i.e., fight-or-flight responses, higher OT levels may reduce the stress reactivity of physiological systems and trigger a tend-and-befriend response in the face of anxiety provoking situations. Therefore, the differential OT levels derived from early life experiences could account for the heterogenous nature of social problems associated with child maltreatment.
学位名
博士（文学）
学位授与機関
甲南大学
学位授与年度
令和4年度(2022年度)
学位授与年月日
2023-03-31
学位授与番号
34506甲第122号
フォーマット
application/pdf
著者版フラグ
none
注記
本論文は内容を学術雑誌(Psychological Trauma: Theory, Research, Practice, and Policy)に掲載しているため、要約のみを公開する。
甲南大学 〒658-8501 神戸市東灘区岡本8丁目9番1号 Konan University 8-9-1, Okamoto, Higashinadaku, Kobe, Japan.
Child Maltreatment and Oxytocin as the Physiological Bases for Social Functioning and Stress Coping
本文（要約）
(1.41MB)
トップページ
