Margot Robbie has said that she had to use psychologist methods to get to understand her “Suicide Squad” co-star Jared Leto better since he was always in character and it was difficult to get to know his true self.

The 26-year-old actress confessed it was difficult to “get through to him at first”.

Jared Leto, who made headlines for giving his co-stars gruesome gifts like used condoms and a dead pig, has turned heads with his method acting transformation into the Joker’s persona, but it has left Robbie wondering what her character would do to connect with her on-screen love interest.

“He’s in character all the time,” Robbie says of Leto. “I spent a lot of time trying to figure out their relationship. Because he’s got his facade up, it was really hard for me to get through to him at first. So I was like, OK, I gotta [approach] this as if I am trying to crack the Joker.”

As a result, she borrowed a leaf from Harley Quinn’s playbook — a doctor who goes evil after falling in love with the Joker — and went head-to-head with Leto on set.

The “Tarzan” actress looked into MMPI Testing, or Minnesota Multiphasic Personality Inventory, which is a popular psychological exam for determining personality characteristics and psychopathology.

“It’s a test that psychologists use to determine what mental illness people might have. It’s a list of 500 questions or something. Whenever we had time to rehearse or improvise, or even in the scenes, I’d just start with those questions,” she explains. “Some of them are basic, and some of them are not. [I’d] see which ones would catch him off guard, how he’d react, and I’d be like, ‘OK, I’m gonna go for this tactic now. It’s a lot of trial and error.”

The Joker’s relationship with Robbie’s character is likened to dating an addict. “It’s kinda like when your friend is doing something stupid in a relationship, and you’re just so frustrated. You’re like ‘What are you doing? Why?'” she explains. “I landed upon codependency as the tact to take… It’s like a compulsion, I suppose. When you start looking at it the way an alcoholic is compelled, you know, needs to have a drink. You think of it in those terms, like it’s an actual psychological problem, which codependency actually is.”

Margot previously said that she took a job in ‘Suicide Squad’ without reading the screenplay.

She said: “I never really thought to myself, ‘Oh, I want to be in a comic-book movie’. When I first about it I was about to do a different project, and they said, ‘Before you sign on for that, would you consider playing Harley Quinn?’

“I was like, ‘Okay, can I read the script?’ And they were like, ‘There’s no script.’ ‘Okay, is there anyone attached?’ ‘No one attached.’ ‘… Is there a director?’ ‘Yeah, David Ayer.’ And I was like, ‘Well, I’m in!’ And that was kind of it!

“I didn’t sign on to do a comic-book movie, nor had I ever expected to. But if I was to do it, David was the guy I wanted to work with.”