The purpose of this study is to examine the mediating effect of passive coping style and psychological acceptance in the relationship between adult ADHD propensity and depression in adults aged 20 to 39. This study collected and analyzed data from 150 adults aged 20 to 39 in men and 150 in women. Unlike research trends on ADHD in Korea, this study is meaningful in that it selected research subjects other than college students and used two variables, passive coping style and psychological acceptance, which were rare in previous studies. As a result, First, adult ADHD propensity and depression were positively correlated. Second, psychological acceptance was found to have a meaningful negative correlation with adult ADHD propensity and depression, and a negative correlation with passive coping style. Third, positive correlation was found on passive coping styles with adult ADHD propensity and depression. Most noteworthy is that psychological acceptance and passive coping style have verified the dual mediating effect that sequentially affects depression in the relationship between adult ADHD propensity and depression. The implications and the limitations of the study were discussed.