Non-Consensual Sexual Experiences Before Age 18 and Adult Mental and Physical Outcomes in Japan: A Population-Based Study

Abstract

Non-consensual sexual behavior (NSB) before age 18 is a recognized risk factor for adult mental ill-health, yet evidence from Japan remains limited. We analyzed data from adults who completed the nationwide, Internet-based Japan COVID-19 and Social Internet Survey (September–October 2022). Exposure was any self-reported NSB ≤18 years. Outcomes were physician-diagnosed or self-reported depression, anxiety, post-traumatic stress disorder (PTSD), suicidal ideation, low self-esteem, relationship distress, chronic pain, smoking, and alcohol use after age 18. Multivariable logistic regression was adjusted for sex, marital status, education, income, and employment; sex-stratified models and interaction terms tested effect modification. Among 28,221 participants, 535 (1.9%) experienced NSB, including 157 men (29.4%). NSB experience was significantly associated with a higher risk of depression (odds ratio [OR] = 5.03, 95% confidence interval [CI] [4.13, 6.14]), anxiety (OR = 5.10 [4.12, 6.32]), PTSD (OR = 18.42 [13.73, 24.74]), suicidal ideation (OR = 4.47 [3.63, 5.51]), low self-esteem (OR = 3.31 [2.71, 4.04]), distress in relationships (OR = 2.62 [2.11, 3.25]), chronic pain (OR = 2.61 [2.15, 3.17]), and smoking (OR = 2.39 [1.91, 3.00]; all p values < .001). Effect sizes for depression, anxiety, PTSD, and low self-esteem were significantly larger in men than women (interaction p value < .01). Experiencing NSB before age 18 is associated with substantial mental health and somatic burdens in Japanese adults. Both male and female survivors require attention, with men exhibiting particularly pronounced psychological symptoms. These findings underscore a need for survivor-centered mental health screening, support programs, and policy initiatives that lower stigma and enhance access to care.