Childhood Intrafamilial Aggression, Peer Bullying Linked to Adult Depression

These findings have important implications to mitigate the effect of early-life stress and promote life-course mental health through dealing with childhood intrafamilial aggression and peer bullying experiences.

Childhood peer bullying has been shown to be a mediator of the association between childhood intrafamilial aggression (ie, parental physical maltreatment and sibling aggression) and depression in adulthood. A population-based, cross-sectional study on the topic was conducted that used data from the 2015 wave of the China Health and Retirement Longitudinal Study (CHARLS 2015) combined with the CHARLS life history survey. Results of the analysis were published in the journal JAMA Open Network.

The investigators sought to explore the mediating role played by childhood peer bullying in the link between childhood intrafamilial aggression and depression in adults. Study enrollees, who were ≥45 years of age, participated in the CHARLS life history survey from June 1 through December 31, 2014, and in the CHARLS wave from July 1 through September 30, 2015. They utilized a 4-step mediation model with logistic regression to examine the mediating role of peer bullying. Data analysis was carried out between October 1 and October 30, 2019. The main study outcome measure was the Center for Epidemiologic Studies Depression Scale (CES-D).

A total of 18,780 individuals participated in the CHARLS life history survey and the CHARLS 2015 wave. Overall, 1796 individuals were excluded because they did not complete the CES-D and 1534 individuals had missing values, leaving a total of 15,450 participants who had data available on childhood adverse experiences, adult depression, and confounders. Parental physical maltreatment was recognized by response to the following questions: “When you were growing up, did your parents or guardian ever hit you? Was that often, sometimes, rarely, or never?” Similarly, sibling aggression was identified with the following question: “When you were growing up, did your siblings ever hit you? Was that never, rarely, sometimes, or often?”

The mean participant age was 59.5 ± 9.9 years. Overall, 51.7% of the participants were women. 28.6% had been exposed to parental physical maltreatment, 6.4% had been subjected to sibling aggression, and 16.2% had experienced peer bullying in childhood.

Those respondents who had experienced intrafamilial aggression were more likely to have been bullied by their peers (parental physical maltreatment: odds ratio [OR], 2.53; 95% CI, 2.25 to 2.83; sibling aggression: OR, 1.40; 95% CI, 1.13 to 1.74; and peer bullying: OR, 1.78; 95% CI, 1.56 to 2.01). In fact, peer bullying mediated 30% of the association between childhood parental maltreatment and adult depression (95% CI, 19% to 42%). Additionally, peer bullying mediated 35% of the association between sibling aggression and symptoms of depression in adulthood (95% CI, 15% to 54%).

Limitations include crude measurements due to the data constraints of CHARLS and the fact that the effects of onset and severity of childhood adverse experience were not investigated in this study. In addition, the indicators to measure childhood adverse experience were retrospective self-evaluation with potential measurement error issues, whereas prospective evidence suggests that effects of childhood adverse experience reach this far.

The investigators concluded that the findings from this study have significant implications for mitigating the impact of early-life stressors and promoting life-course policy on mental health through dealing with the experiences of childhood intrafamilial aggression and peer bullying in a coordinated fashion.


Wang Q. Association of childhood intrafamilial aggression and childhood peer bullying with adult depressive symptoms in China.  JAMA Netw Open. 2020;3(8):e2012557. doi: 10.1001/jamanetworkopen.2020.12557.