For more than a decade, a generation of viewers has grown up alongside Sophia Bush and her portrayal of Brooke Davis on The CW's gone but not forgotten One Tree Hill. Now, those same, slightly older audiences are settling in for what could be the long haul with the actress' current role as Detective Erin Lindsay on NBC's Chicago P.D.

To say things have been confusing for Lindsay on NBC's Chicago Fire spinoff as of late would be an understatement. Between reintroducing her mother, Bunny (Night Court's Markie Post), to her life as well as joining — and quitting — the task force, she's had to make some big life decisions. Wednesday's episode, appropriately titled "Erin's Mom," won't exactly divert from that trend when Bunny suddenly finds herself caught up in a robbery/murder case.

THR caught up with Bush to get her take on growing with her roles, getting a behind-the-scenes education and following in the footsteps of Law & Order: SVU ace Mariska Hargitay.

See more Broadcast TV's Returning Shows 2015-16

Do you compare Lindsay's recent storylines to some of the growth you've experienced in your career?

I don't think there's any relation between my last job and this. I've always known I have all these different people in me character-wise, but as an actor, when you do a job for so long, the public gets so used to you being that person that they think you are that person. I crammed in other jobs so I could play other people. What's nice about the way Chicago P.D. has hit is that I get to show people something else. It's nice to get to flex in a different way.

Did you feel you wanted to stay ahead of the curve when you started directing?

It's about multitasking and the confidence that naturally comes with experience. They talk about how women get so much more confident in their 30s. That isn't because of your age, it's because you've worked long enough to realize that the fear that you are less than enough is just ego. You get to a point where you care less about your own anxiety and fear. If we're thinking about the 10,000 hours theory, I've done mine. I've realized I had an education. Being in the realization and confidence stage, it feels like I'd better get cracking on all those things I want to do. If not now, when?

Does that mean you're looking to direct more?

I would love to, but it's complicated because of the shooting schedule. My co-workers and I, from Fire and P.D., we've actually been talking about maybe taking this second half of the season and writing a short together. We're stuck in Chicago and it's freezing and we don't want to go outside. So I sort of was like, "Well why don't we do something other than sit on the couch and spitball at each other?" So we'll see. It's tough because when you have a little bit of free time at this point of the year, everyone's trying to go home because we're homesick.

You're very active for your causes. When did you find your voice?

I was always active and I always had a voice in my personal space. I'd had a really lovely life. I'd never been prayed upon, I'd never been grotesquely lied to. I'd observed plenty of bullshit, but never by anything happening to me. Working on a show that revolved around such drama and suddenly having the public eye on us and our mistakes felt so invasive. So I tried to be as quiet publicly about anything that mattered to me; I was so seized up by how icky all of that prodding felt. Then I realized I wasn't talking about what mattered to me. When that light switch flipped, I started screaming.

Read more NBC's 'Chicago Medical' Spinoff Taking Shape

When you refer to the icky stuff, are you referring to your personal relationships?

Yeah, it's just such a weird thing. Why would we marginalize anybody based on some stupid person they dated or like, someone falling out of a cab because they rolled their high heel and maybe they were tipsy? It's like, they want to splatter these girls around like they're some hot mess. Why are we constantly working on taking women down? I loved that Levo League started #AskHerMore, because men were being asked things like, How did your role influence you? Or, how do you feel this has changed your viewpoint on the world? And they were asking the women like, what are you carrying in your clutch? … What is that? At 21, having been in college and planning fundraising events to suddenly having everyone in the universe asking me weird shit about my life … I just didn't know how to handle it. Now I roll my eyes at it and keep the conversation moving.

Do you find that you take roles that speak to you in the same way?

I only ever actively pursue roles that speak to me. The catch-22 of being on a show that lasts is that you have a job and you're making a living playing pretend. It's the best thing in the world. But you also have a job so you can't take any other jobs. There were a lot of things during One Tree Hill that I missed out on. When it finished, I wanted to get away from relationship drama so badly, and I'd always loved Max Mutchnick and David Kohan's (Will & Grace) work, so I jumped at the chance to work with them on [CBS' short-lived comedy] Partners. Then, in examining what I wanted to do next, I'm one of those weird people who things are meant to be. I was cast on the Hatfields & McCoys pilot with my good friend Patrick John Flueger. And with Jesse Lee Soffer. I knew in my gut the show wasn't going to get picked up. I don't know why, but I did. I also knew I was supposed to work with those people. Then one by one we all got cast on P.D.

When did you know Chicago P.D. was your next role?

P.D.just resonated with me. I was in no rush to jump into something, but I remember reading the pages for this and just knowing her. Immediately. I went into the room, I'd read it once, and I read it one more time before I went in and read for the whole team. They never made me come back in to read again. Matt Olmstead and Dick Wolf didn't just want Lindsay to be some stereotypical strong woman, a sidekick or some piece of ass for a male character … they wanted her to be so fully fleshed out.

If P.D. went the way of Law & Order: SVU, you could be in this for a while. Could you see yourself being the next Mariska Hargitay?

She's the coolest. She was joking with me the first day that we shot our first crossover of P.D. and SVU, and she went, "So should I hand her the torch at the beginning of the scene or the end?" We were like crying laughing. She is the funniest, most amazing woman. We'll see. As of this moment, I can't imagine not wanting to do this job.

Chicago P.D. airs on Wednesdays at 10 p.m. on NBC.

Twitter: @amber_dowling