Varenicline precipitating psychosis in a patient with no previous psychiatric history: a case report of a Spanish patient who was later diagnosed with paranoid personality disorder.

Varenicline is gaining popularity for the treatment of nicotine dependence. General treatment guidelines recommend monitoring for behavioral changes in patients with a mental illness. There are very few cases reported on patients developing psychiatric symptoms with no previous history. We are reporting the case of a Spanish patient who had developed a first-psychotic episode after he was started on varenicline. He was ultimately diagnosed with a paranoid personality disorder. Therefore, prior to starting a patient on varenicline, the clinician must identify possible paranoid and other cluster A personality traits. It is essential to monitor for new onset of psychotic symptoms during the treatment with this drug.