In an interview with the New York Post, Lanter explained that his problems will not be resolved quickly.
"That's part of his personality," he said. "It's always going to be there. [In] season one he really started acting out, but that was before we got to know him.
"Now we've seen his vulnerable side, but it'll always be there - even in season three, he's already gotten into a couple of fights. He might or might not have been on a boat that isn't his. Stuff like that."
Lanter also revealed that he is excited about the third season and promised: "[There will be] juicy drama, complications, love triangles, backstabbing, sexual escapades and... whatever else the writers can think of!"
The third season of 90210 begins on September 13 on The CW.