Only a few years ago, Sulli and Goo Hara were at the height of their powers, two K-pop stars whose talents had brought them fame across Asia. But in the space of six weeks, both women died.

Sulli, 25, took her own life in October after years of online abuse. Her close friend Goo, who was the same age, had just completed a solo tour of Japan when her body was found at her home in Seoul last weekend alongside a note that police said indicated she had been feeling “pessimistic”.

Goo had made enemies of online commenters and the tabloid media for taking action against an ex-boyfriend who had allegedly threatened her with revenge porn. Sulli had attracted hate for her feminism and public battle with depression. Both refused to play the roles demanded of them by many of their compatriots.

“Some female idols have been ostracised for not smiling in a television show and reading a book about feminism that contradicts male-dominated, patriarchal South Korean society,” Park Hee-A, a K-pop journalist, told the Associated Press.

Their deaths, along with a recent sexual abuse scandal, have put the industry under unprecedented scrutiny over its treatment of women, many of whom are spotted in their teens and subjected to an unforgiving regime of song and dance training that leaves no room for everyday pleasures.

They also pose uncomfortable questions about the toxic mix of misogyny and taboos over mental illness that experts say is ruining lives beyond the highly pressured confines of the music industry.

Sulli was the target of online abuse for not wearing a bra, for live-streaming an innocent night out drinking with a friend, for addressing older male colleagues by their first names and – her most egregious “crime”, it seems – for describing herself as a feminist.

Facebook Twitter Pinterest Sulli was a member of the girl group f(x). Photograph: Yonhap/AFP via Getty Images

“South Korean society is holding on to the idea that men must be respected and women are not deserving of respect, or at least not much,” said Ryu Sang-ho, a neurologist at Haedong hospital in Busan. “The media feed off that, so it’s no surprise that the public don’t have any sense of empathy towards these women.”

A year before her death, Goo had taken her ex-boyfriend Choi Jong-bum to court after he threatened to release a video of the couple having sex. Choi was convicted of assault and blackmail and given a suspended 18-month prison sentence, but he was cleared of illicit filming. Both sides appealed and the case had not been settled at the time of Goo’s death.

There was little public sympathy for Goo during the trial, with the singer attracting a barrage of online abuse and lurid tabloid stories over her violation of an immutable law of K-pop stardom: to appear at once innocent and sexually available.

“The topic of sex is taboo in South Korea compared to western countries,” said Tae-sung Yeum, a psychiatrist at Gwanghwamun Forest psychiatric clinic. “There’s a high moral standard required, especially for female celebrities, because South Korea is a patriarchal society.”

There are signs that attitudes are changing. Goo’s death sparked a petition to the website of the South Korean president, Moon Jae-in, calling for stronger punishments for abusive online comments. It attracted more than 20,000 signatures in less than a day. The national assembly will soon begin debating a bill nicknamed Sulli’s law to combat online abuse.

But that is treating only part of the South Korean mental health malaise that has been brought into sharp focus by Sulli and Goo’s deaths. It is no coincidence that a decade in which several celebrities have taken their own lives, including the male singer Kim Jong-hyun, coincided with a rise in mental illness and suicides throughout South Korean society.

The country has one of the world’s highest rates of suicide, which is among the leading causes of death among people under 40. Taboos about mental illness prevent many people from seeking help.

K-pop stars, like millions of other South Koreans, are discouraged from seeking help for depression, which is still viewed as a failure of moral character.

“The blame lies with South Korean society in general,” said Ryu. “Many people with mental health issues are reluctant to take medication for fear of being seen as weak-minded. Mental health problems should be treated in the same way as a common cold. South Korean society needs to catch up.”

Additional reporting by Nemo Kim in Seoul.