The study followed 10,000 teenagers born between 1999 and 2004. The teenagers were asked questions about thoughts and acts of self-injury between 2014 to 2016.
According to study co-author Dr. Pilar Rioseco, the findings are very "concerning." The report found that 30 percent of teenagers between the ages of 14 and 17 had thought about self-harm, and 18 percent had committed acts of self-harm.
According to Rioseco, thoughts and acts of self-injury among adolescents increase as they get older. By the age of 14 to 15, 16.4 percent of teenagers will have thought about self-harm, and 9.7 percent of them will have committed acts of self-injury. By age 16 to 17, this rises to 21.2 percent for self-harm thoughts and 11.2 percent for acts.
The report also founds that repeat incidences of self-harm over time were strongly associated with suicidal behavior. Sixty-five percent of those who engaged in repeat incidents of self-injury reported attempting suicide by the ages of 16 and 17.
The report also found that experiencing bullying and poor sleep, as well as having other mental health concerns such as depression and anxiety, were all associated with a higher risk of self-injury.
The study found a significant difference in the rate of self-harm thoughts and actions between girls and boys. Nearly half of the girls surveyed – 42 percent – reported thinking about self-harm at the ages of 14 to 15 or 16 to 17. Only 18 percent of the boys within the same age groups reported thoughts of self-harm.
For the girls within those age groups, 26 percent reported self-harm, compared to just nine percent of boys.
Girls were also more likely to repeatedly engage in acts of self-harm. The report found that seven percent of girls between 14 to 15 and 16 to 17 repeatedly self-injured themselves, compared to just one percent of boys.
"While both genders are experiencing high rates of self-injury thoughts and behaviors, it is alarming to see how much more common it is among girls," said Rioseco.
According to the report, teenagers who were attracted to members of the same sex were also significantly more likely to think about and commit acts of self-injury.
"As a same-sex attracted person, you are potentially living with the stress of being a stigmatized minority," explained Rioseco.
Same-sex attracted adolescents were more likely to commit acts of self-harm at some point between the ages of 14 and 17, at 55 percent, compared to people who were not attracted to the same sex, at just 15 percent.
"Despite progress over the last few years, same-sex attracted adolescents may still find they have to contend with harassment, discrimination and bias from family, peers and schools," explained Rioseco.
"Ultimately, self-injury thoughts and behaviors need to be seen for what they are: A response to mounting stress and a way of relieving emotional pain," explained Rioseco.
"There's an urgent need for integrated care involving families, schools and communities to enhance safety among these distressed young people in both the short and long-term." (Related: COVID-19 lockdowns causing deterioration of children's mental health.)
"Navigating your way through the world as a young person can be challenging and it's clear that managing self-injury thoughts and behaviors is a critical aspect of adolescent healthcare provision," said Rioseco.
"If we don't put in place preventative measures, we will be at the pointy end of crisis prevention," said Helen Christensen, outgoing director and chief scientist of the Black Dog Institute, the mental health research arm of the Christian charity organization, Mission Australia.
According to Christensen, the Australian government has not made significant investments in preventative care programs, particularly in schools. She is worried that without the proper intervention, the mental health crisis adolescents in Australia are experiencing will only get worse.
"We really need to do something now if we are going to be in a better position in five or 10 years."