BackgroundThe prevalence of depression is higher among midlife women, and they have less control over their diabetes during the menopausal transition. However, there is limited evidence on the association between type 2 diabetes mellitus and depression among Korean women in their midlife. This study aimed to examine the association between type 2 diabetes mellitus and depression and explore the levels of awareness and treatment of depression among Korean midlife women with T2DM.MethodsThis is a cross-sectional analysis study conducted using data from the Korea National Health and Nutrition Examination Surveys of 2014, 2016, and 2018. Korean women aged 40–64 years who randomly participated in the surveys were included, and 4,063 midlife women were selected as study participants. The diabetes progression status of the participants was classified into diabetes, pre-diabetes, and non-diabetes. Furthermore, the Patient Health Questionnaire-9 was used for screening depression. Participants’ awareness rate, treatment rate among incident cases of depression, and treatment rate among awareness cases of depression were also analyzed. For data analysis, the Rao–Scott χ2 test, multiple logistic regression, and linear regression were conducted using SAS 9.4 software program.ResultsThe prevalence of depression significantly differed between diabetes, pre-diabetes, and non-diabetes groups. However, depression awareness, treatment/incident, and treatment/awareness rates did not differ statistically between the diabetes progression status groups. Compared to the non-diabetes group, diabetes group had a higher odds ratio of depression after adjusting for general and health-related factors. Thus, the diabetes group had significantly higher PHQ-9 scores than the non-diabetes group after adjusting for covariates.ConclusionsWomen in their midlife who have type 2 diabetes mellitus tend to have higher levels of depressive symptoms and are at risk of depression. However, we found no significant differences between diabetes and non-diabetes regarding the awareness and treatment rates of depression in South Korea. We recommend that future studies focus on developing clinical practice guidelines aimed at additional screening and intervention for depression in midlife women with type 2 diabetes mellitus to ensure prompt treatment and improved outcomes.