Though there’s no shortage of teenagers keen on the pop-rock band 5 Seconds of Summer, few fans have channeled their enthusiasm into action as effectively as Peabody resident Ashley Royer, 17, who last month published “Remember to Forget’’ through HarperCollins. The book, which follows the life of a depressed teenage boy following his girlfriend’s death, started out as band-centric fan fiction. We spoke to her by phone.

Q. When did you become involved in online fandom?

A. I’ve been on [community writing site] Wattpad since 2012. My friend had told me about it one day at a movie theater and I had no idea what it was, but a few months later I made an account for it and started writing on there. I wanted to write stories people could connect with and relate to, and I wanted to help others through my stories.

Q. What changes were necessary going from fan fiction to a published novel?

A. On Wattpad, I used the names of the band members, but the characters had nothing to do with their personalities. Now, in the published version, the names had to be changed, but I didn’t have to change anything about the characters because it wasn’t anything about any real-life people.

Q. How did HarperCollins get involved?

A. When I started [writing on Wattpad], I didn’t tell anyone. . . . My mom sat me down one day and said she’d found it and that she thought I should do something with it. She got me an agent and sent out the book to publishers. Within three months, I had a response from HarperCollins.

Q. How did you tackle the book’s heavy themes?

A. A lot of things in the book are things my readers go through. I made sure I did a lot of research on depression and anxiety so I was saying the correct things, and not making false statements about anything. I’d usually write one chapter a week, and my readers could comment on any section, so I would read almost every comment and message I received. That helped shape the story.

Q. What’s next for you?

A. I’d love to keep writing, though I’m still a junior in high school so it’s difficult. I’ve thought about a sequel, and I want to continue writing as I continue on. This has changed what I may be doing with the rest of my life.

Isaac Feldberg can be reached at isaac.feldberg@globe.com.