Sunmi recently opened up about being diagnosed with a borderline personality disorder, a mental health condition that causes the sufferer to experience mood swings and difficulties with interpersonal relationships.

According to a report by All Kpop, Sunmi shared in a recent episode of Running Mates that she was diagnosed with borderline personality disorder around five years ago. She explained that during her days as part of Wonder Girls, she was having difficulty coping with the demands of stardom, leading her to leave the group briefly and rejoin her members again later.

Sunmi shared with her fellow Running Mates cast members that it was okay to take a break when things get hard because this was part of caring for oneself. She said she was happy that she got diagnosed because it enabled her to get treatment for her condition. Since taking medication, she said that she got better. She assured because she is doing better now, her doctors have decreased her medication.

However, her mental health condition was not her only challenge. Sunmi confessed that the bottom line was that she had to resolve a lot of things because a lot of people suffered as an aftermath of her borderline personality disorder.

She offered a lot of advice to her younger co-stars like EXID's Hani, Oh My Girls' YooA, Chung Ha, and LOONA's Chuu. She said that she experienced many of the things that they are going through now.

She attributed some of the challenges of starting so young in the entertainment industry. She said that she and her Wonder Girls co-members spent most of their younger years in a car, traveling to different schedules when they should have been exploring their sense of self and their role in society.

Sunmi advised her Running Mates co-stars to look back on their past and re-evaluate the things that are important to them and the things that they are good at. She said that she is happy that they got to work on the show together because they had many opportunities to see each other in the past but never got the time to bond.

After the Running Mates episode aired, a lot of fans expressed worry for Sunmi, prompting the "Gashina" singer to address them on WeVerse.

In her post, she asked fans not to worry and assured them that her experience has made her stronger. She added that she also became healthier nowadays, All Kpop reported.