An Open-label, Multicenter Trial to Assess the Long-term Safety and Tolerability of ITI 1284 as Either Adjunctive or Monotherapy Treatment in Patients With Generalized Anxiety Disorder (GAD) With a History of Inadequate Response to GAD Treatment
The purpose of this study is to assess how safe ITI-1284 is and how well it can be tolerated in long-term, when given alone or with other medicines, in participants with generalized anxiety disorder (GAD) who have not responded to treatment previously. GAD is a mental health condition defined by constant, uncontrollable worry about everyday things that lasts for six months or more.
• Provide written informed consent before the initiation of any study specific procedures
• Is currently an outpatient, and is anticipated to maintain outpatient status for the duration of the study
• Male or female of childbearing potential and agrees to use a highly effective method of birth control from the time informed consent is provided until 30 days after the last dose of ITI-1284 for females and 90 days after the last dose of ITI-1284 for males
• Ability to follow study instructions and likely to complete all required visits
• In the opinion of the Investigator, the patient must have safely completed the lead-in study (ITI-1284-301 or ITI-1284-302)
• If entering from lead-in study ITI-1284-301, must be expected to continue their ongoing anti-depressant therapy (ADT) or buspirone from the lead-in study
• Provide written informed consent before the initiation of any study-specific procedures
• Male or female participants greater than or equal to (\>=) 18 years of age
• Has a body mass index (BMI) of 19-40 kilogram per meter squared (kg/m\^2), inclusive
• At screening, meet diagnostic and statistical manual of mental disorders, fifth edition, text revision (DSM-5-TR) diagnostic criteria for moderate or severe generalized anxiety disorder (GAD) (current GAD) as confirmed by the investigator or sponsor-approved rater using the structured clinical interview for DSM-5, clinical trials version (SCID 5-CT)
• Is currently an outpatient, and is anticipated to maintain outpatient status for the duration of the study