"My depression made me feel unworthy of being a starting player on the field," says Jacklyn Oleksak, 22. Oleksak played softball at Stonehill College in Massachusetts for more than three years before quitting the team and transferring to Hofstra University in New York. "It made me feel like I was letting my team down whenever I made a single mistake, even during practices. It made my self-esteem plummet," she says.

Oleksak is part of a rising number of female college athletes grappling with mental illness. According to a 2016 study, about 30 percent of surveyed female student-athletes showed signs of depression, compared to just 18 percent of their male counterparts. Female track runners exhibited the highest degree of symptoms—a new book, What Made Maddy Run, by ESPN's Kate Fagan, delves into this sad phenomenon as it played out for 19-year-old Madison Holleran.

The University of Pennsylvania track athlete entered the game strong as a freshman. Holleran was bright, congenial, had a strong support system, and enviable athletic skill. Though her family knew she had been struggling with her transition from small-town soccer champ to Division I sports star, they were blindsided when she killed herself in 2014. Holleran's sister, Carli, told Fagan in 2015: "With Madison, it feels like one day she was happy, the next she was sad, and the day after she was gone."

As Fagan—who used the young athlete's texts and emails to help flesh out Holleran's voice in the book—tells it, no one knows exactly when things shifted for the 18-year-old, whose friends described her as thoughtful, fun, and full of life. Something did change, though, and it began to happen after Holleran immersed herself in the high-stakes world of Ivy League Division 1 sports (there have been 12 student suicides at UPenn since 2013).

She was no longer running for fun, or as an occasional complement to her lifelong love of soccer. Now she was running competitively at a hallowed institution, with all the accompanying pressure that can hold. "One of the biggest misconceptions about student athletes is that they live a sheltered or 'spoiled' life—that because many of them are on scholarship, they have unearned or undeserved luxuries," says Denise Kwok, director of student-athlete academic services (SAAS) at University of Southern California.

The reality is very different. While student-athletes like Holleran may attract some measured fame, they're often spread brutally thin, fighting to maintain a stellar academic performance along with a grueling physical routine. "Even when your brain needs a break, sports never stop," Oleksak says. "[In college sports,] there is no such thing as a ... mental health day. We are supposed to be able to balance athletics, schoolwork, and a social life, which is so difficult. Adding a mental illness [makes it] even harder."

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Holleran showed signs of intense stress as she juggled sports and academics, and that act became harder to maintain as her emotional state became more tenuous. As her first semester at Penn wound down, Fagan describes Holleran telling nearly everyone she knew that she didn't want to run track at Penn anymore. Holleran, who also loved writing and art, flirted with the idea of transferring to Lehigh.

When she finally decided to quit track, she read a candid letter to her coach: "I feel like I've dug myself so deep and ... there isn't any coming back. I've thought long and hard about this and feel that I just need to take the semester off to figure out what I really want in life and who I really am." After her coach listened to the letter, he offered to work with Holleran at a slower pace if she considered staying put. She agreed to try, but ended her life shortly into her second semester.

Fagan can relate to at least some of Holleran's struggles, confessing that "there was a lot of overlap between me and Maddy" during Fagan's 1999-2004 tenure playing basketball at the University of Colorado at Boulder. Though Fagan didn't struggle with clinical mental illness, she did consider leaving her team because of the fervency of the unforeseen pressures that arose. "I was ready to quit and move home," she recalls. It's especially challenging when everyone around you seems to expect you not only to handle the ongoing stress, but to do it silently, and with a smile.

Being mentally tough is part of the traditional college-athletics mindset, Oleksak says, noting, "When mental illness strikes, student-athletes [can be] less likely to be open about it or get help." She chalks this reluctance up to the false idea that "as athletes we can overcome anything."

Becca Martin, who experienced mild depression while playing lacrosse at Edinboro University of Pennsylvania (she graduated in 2016), agrees, remembering the common belief that "when you're at practice, nothing else matters." This line of thinking was not only difficult to swallow—athletes are human, too—but potentially harmful to players already dealing with mental health concerns. "You're supposed to pretend it doesn't exist. You're not allowed to have off days and if you do, you're going to get ... chewed out," she says.

It's unclear exactly why women athletes appear more susceptible to mental illness than men. Fagan says, "In all my reporting, it's hard to find a direct causality." But Patricia Allen, a counselor, executive director of medical services at Summit Behavioral Health, says "I think a lot of female athletes try to achieve in a different way. There's more pressure on them to be strong, successful, competitive, healthy, and resilient."

There can be other challenges for these young women, too, such as body image issues. Though statistical research varies when it comes to the prevalence of eating disorders among student-athletes, according to a 2015 study, female collegiate athletes show a higher risk of disordered eating "by approximately 14 percent to 19 percent compared to their male counterparts." Allen also says that it's common for female student-athletes to fall prey to a condition called the Female Athletic Triad, which the NIH describes as "an interrelationship of menstrual dysfunction, low energy availability (with or without an eating disorder), and decreased bone mineral density."

And then there's the spotlight, and everything a woman athlete is expected to be when she's in it. Holleran had an active Internet presence, with photo after happy photo depicting a highlight reel of her laughing, competing, and partying with friends. Social media's unique insistence that one's life always be perfectly packaged can put even more pressure on young athletes who may already be on the proverbial ledge. "The ever present pressure of social media, technology, and the [public's] desire ... to be informed and in the know, particularly for more high-profile athletes, makes it difficult," Kwok says. "Students [are] living under a spotlight they aren't necessarily prepared for."

According to NCAA statistics, suicide is the third leading cause of death among student-athletes, and that hasn't gone without notice by the organization. In 2013, the NCAA's chief medical officer declared mental health a top priority for the organization, and since then, universities across the country have made a stauncher effort to expand their support for student-athletes. At USC, Kwok says, "We devote a team of four full-time licensed psychologists who are specifically trained [to work] with the mental health care and performance issues of our athletes." The school also works with a psychiatrist who is solely dedicated to assisting the school's athletes.

For the young women athletes who still find themselves caught in the fog of mental illness, though, it's a day-to-day fight that isn't easily won. "People tend to not realize that mental illness is not a choice," Oleksak says. "'Thinking positively' or trying to smile more will not cure depression or anxiety. It is much deeper and more complex than that."