Background: When assessing patients with depressive and anxiety disorders in psychiatric clinical practice, it is common to encounter children and adolescents who have experienced abuse and victimization. To date, it has been clarified that experiences of "childhood abuse" and "childhood victimization" lead to "neuroticism", and that neuroticism leads to "adult depressive symptoms". In this study, we analyzed how these four factors are interrelated. Subjects and Methods: The following self-administered questionnaire surveys were conducted in 576 adult volunteers: Patient Health Questionnaire-9, Eysenck Personality Questionnaire-revised shortened version, Child Abuse and Trauma Scale, and Childhood Victimization Rating Scale. For statistical analysis, Pearson correlation coefficient analysis, t-test, multiple regression analysis, and covariance structure analysis (path analysis) were performed. Results: Path analysis showed that the indirect effects of childhood abuse and childhood victimization on depressive symptoms through neuroticism were statistically significant. In addition, the indirect effects of childhood abuse on neuroticism through childhood victimization were statistically significant. Finally, the indirect effects of childhood abuse on depressive symptoms through the combined paths of childhood victimization and neuroticism were statistically significant. Conclusion: Our results suggest that "childhood abuse (A)" induces changes in the personality trait of "neuroticism (C)" with "childhood victimization (B)" as a mediator, and that these adversities affect the expression of "depressive symptoms in adulthood (D)" through "neuroticism (C)" as a mediator. In other words, to our knowledge, this is the first study to clarify that these four factors are not only individually associated with each other but also cause a chain reaction of A to B to C to D.