Subjects will be screened and will undergo pupil measures with rating scales on Visit 1. Subject must be free of all psychotropic medications for one week before Day 1 assessment, except that prior FLX treatment will require 4 weeks of abstinence, and MAOIs will require 2 weeks of abstinence. They will be randomized to study drug an issued six weeks of study medication on Day 1 to take home. A phone call will then occur for safety assessment and medication adherence at every week. They will present back to the study site on Day 42 and undergo pupil measures with rating scales. They will then undergo a one week washout period. On Day 49 they will then be given another study drug to take home with rating scales and pupil measures obtained that day. A phone call will then occur for safety assessment and medication adherence at every week. They will present back to the study site on Day 91 and undergo pupil measures with rating scales. They will then undergo a one week washout period. On Day 98 they will then be given another study drug to take home with rating scales and pupil measures obtained that day. A phone call will then occur for safety assessment and medication adherence at every week. They will present back to the study site on Day 140 and undergo pupil measures with rating scales. No more study medication will be provide on Day 140 and a final visit will be scheduled for on Day 147, one week later, for and end of study interview with labs and physical exam. At each visit, other than the final visit, subjects will complete the CAPS-5, MADRS, Insomnia Severity Index, and Clinician Assessment for Adverse Effects.