Study Purpose: This study is testing a new medicine called ITI-1284 for people with Generalized Anxiety Disorder (GAD) who haven't had much success with other treatments. GAD is a condition where people feel very anxious or worried most of the time.

Study Process:

• First, there's a Screening Period (up to 2 weeks) to see if you can join the study and to stop any medicines that aren't allowed.
• Then, a Double-blind Treatment Period (6 weeks) where you might get ITI-1284 (10 mg or 20 mg) or a placebo (a fake pill). Neither you nor the doctors will know which one you get.
• Finally, a Safety Follow-up Period (1 week) to check on your health after the treatment.

Things to Know:

• The study lasts about 9 weeks in total with several visits to the clinic.
• It's important to meet certain health criteria to join the study.
• You won't know if you're getting the real treatment or a placebo.