I sent my AMCAS in the first week of June, and I heard back from Northwestern around the beginning of August, to give you a timeline. From what I hear, they screen applications fairly rigorously (i.e., they actually read your personal statement, rather than just calculating a formula based on your MCAT and GPA). They give you a 4-wk. turnaround on the app, and the questions are somewhat challenging. Hope this helps.