This study is testing how well a new medicine called NBI-1065890 works for people with a movement disorder called tardive dyskinesia (TD). TD causes involuntary movements, like twitching or jerking. The study will compare NBI-1065890 to a placebo, which is a fake treatment with no medicine in it.

To join this study, you must be diagnosed with schizophrenia, schizoaffective disorder, bipolar disorder, or major depressive disorder for at least 3 months. You also need to have TD with moderate to severe symptoms. However, you can't have other movement problems like parkinsonism or certain psychiatric conditions.

• The study involves multiple visits, so participants should be able to travel to the clinic.
• Participants will be evaluated through video recordings to assess TD severity.
• Compensation may be provided for participation, but details aren't specified.

Remember, joining a study is voluntary and you should discuss it with your doctor to ensure it's right for you.