These symptoms have occurred in people without a history of mental illness and have worsened in people who already had a mental illness. Tell your doctor if you have or have ever had depression, bipolar disorder (mood that changes from depressed to abnormally excited), schizophrenia (a mental illness that causes disturbed or unusual thinking, loss of interest in life, and strong or inappropriate emotions), or other mental illnesses.
If you experience any of the following symptoms, stop taking varenicline and call your doctor immediately: suicidal thoughts or actions; new or worsening depression, anxiety, or panic attacks; agitation; restlessness; angry or violent behavior; acting dangerously; mania (frenzied, abnormally excited or irritated mood); abnormal thoughts or sensations; hallucinations (seeing things or hearing voices that do not exist); feeling that people are against you; feeling confused; or any other sudden or unusual changes in behavior. Be sure that your family or caregiver knows which symptoms may be serious so they can call the doctor if you are unable to seek treatment on your own. Your doctor will monitor you closely until your symptoms get better.
You can also visit the Food and Drug Administration (FDA) website (http://www.fda.gov/downloads/Drugs/DrugSafety/ucm088569.pdf) or the manufacturer's website to obtain the Medication Guide.