Stephen Amell in his new Green Arrow costume The CW

When Arrow season 4 premieres on 7 October, fans will finally get to see the lighter side to the otherwise intense and brooding Oliver Queen. In a recent interview, Arrow's co-showrunner Wendy Mericle spoke about the changes fans would see in the lead character this season.

"It's going to be very different," Mericle told IGN when asked how different Oliver Queen's approach and persona will be in season 4. "...We like to think of the first three seasons as Oliver the soldier coming back from war. We never explicitly said PTSD [Post-traumatic stress disorder] but the implication certainly was there. In the pilot, he's sleeping on the floor, he doesn't have any appetite."

Mericle added that Oliver's relationship with Felicity plays a huge part in the way he approaches his mission and life in general. "This season, we're going to see him in a very different place. When he leaves at the end of Season 3, he's hung up the mantel, he's very loved. He's very happy where he is and that happiness and lightness and the new found faith in humanity that he has, as a result as this relationship with Felicity, is going to redefine how he approaches his mission and how he approaches his life in general and we're excited about that."

The showrunner further revealed that fans will get to see a different shade to Oliver's personality. "It's still the same show and the same character but we're seeing new colors in him," Mericle stressed. Arrow season 4 is set to premiere on 7 October at 8pm ET/PT on The CW.