Gossip Girl Leighton Meester is branching out this year with high–profile roles in Country Strong and The Roommate. Meester took time out of her busy schedule to chat with Street on the latter film, discussing mental illness, roommates and your favorite guilty pleasure TV show.

Street: What was it like trying to play the villain in your first thriller? Leighton Meester: It’s funny — I saw the movie with a couple of my friends, and they were asking me, “how did you like it?”, and I was saying “it’s scary.” I was genuinely scared at points, but it is sort of funny that I’m what’s scary in the movie. I’m really proud of it and how it turned out. It’s definitely a ride — it’s got a lot of levels, it’s sexy and exciting and scary and jarring, and [while] filming it was all of those things too. I can’t say that I wasn’t at all affected by it — I think it stays with you a bit if you’re terrorizing people all day, but overall it’s exciting.

Street: How did you prepare for your role? Did you talk to psychiatrists or do any psychological research? LM: I was really lucky — I had the opportunity to really prepare for this and got a lot of great psychology books and information on delusion and mental disorder, especially in women. I had the chance to speak with different psychiatrists about the disorder and get all kinds of different information. Of course I watched different movies, and this movie is very much like Fatal Attraction or Single White Female. [...]

The psychiatrists I spoke to were really the most helpful because they would describe in gross detail the different cases [and patients] they worked on defending. It’s definitely dark in the mind of someone who is living like this. And it was interesting for me because I have what I believe is a firm grip on reality. I’m weird and crazy like anyone else, but this person really doesn’t have control of her mind whatsoever, and the decisions she makes are not based on rational thinking.

Street: What kind of an impact did playing Rebecca have on you? LM: I can’t say it wasn’t fun — it was — but it was also intense for everyone and it was a really quiet time for me. I try to share something in common with [Rebecca] or try to understand her motives and relate to her in some way. It was extremely difficult for me to do that with her starting off because of how she unravels. From the outside she seems like a really good friend and good person — you know, she’s understanding, she’s artistic, she’s trustworthy — but then eventually she just completely loses that. During filming I did my best to maintain normalcy, and I was really lucky because all I had to do was to work on this movie every day. I got to be very involved and focused which really was a pleasure. But some of the things that I had to do were really disturbing for me, particularly a scene involving a kitchen.

Street: What would you be looking for in the perfect roommate? LM: I actually love living alone. I used to have roommates all the time when I first moved into my own places, and it’s a challenge to live with people. Obviously the best thing about a roommate in a good situation is if you know them and are friends. If you don’t, you have no idea what their habits might be and are taking their friends and their lives into your home. Someone who’s clean I guess? I lived with all different roommates and there were parties going on when I got home. Good roommates are really fun, and for the most part I’ve been really lucky, but I have had some not so good experiences with roommates who eat all your food and take all your clothes.

Street: Who was your favorite person to work with on the set and why? LM: I love Minka [Kelly], and I was so lucky to be able to work with her. She has a light around her. She’s beautiful and so incredibly kind and she was really supportive throughout the whole thing. She has a way of making things light and easy on set, and she’s just brilliant. Of course, I had a lot of pleasure working with everyone. Cam [Gigandet] was really great. He was very respectful of space and the dynamic of our characters. You know, Aly[son] Michalka is such a great girl. I mean, it was a great cast.

Street: How was this role in The Roommate similar and/or different to your role as Blair on Gossip Girl? LM: It couldn’t have been more different. [...] Rebecca has a history of having a mental disorder. It’s not at all the same as what I play day to day on my show, which is a pleasure to break from that and do something different. But it’s also so incredibly different from who I am as a person as well. She’s not making any decisions based on reality; she doesn’t find pleasure in pleasurable things. She only does anything, including interacting with anybody physically or verbally, to gain something for herself, and she uses her intelligence and sexuality to gain control of other people. Meanwhile she doesn’t have any control of her own mind.

Street: What were the similarities and differences between Country Strong and The Roommate? LM: I did them a year apart so obviously it was very different times. I shot The Roommate in LA with Minka who is such a pleasure and so cool, but of course it was a much darker period to work on The Roommate because my character is not completely stable. Whereas for Country Strong we shot in Nashville and I got to work with Gwyneth who I admire so much, and it was essentially a musical so we did a lot of recording and performing.

Street: After playing Upper East Side Queen Blair and mentally ill Rebecca, which type of role do you see yourself wanting to play more in the future? LM: The best part about my job is that I can do different things all the time — I would never want to do the same thing twice, so probably something lighter in the future. I’d like to do something new and completely different.