Risk factors predisposing to psychotic symptoms during levetiracetam therapy: A retrospective study

While levetiracetam (LEV) usage is a known risk factor for psychosis in epilepsy, the modulating effect of certain patient and treatment characteristics on the risk of psychosis has yet to be fully elucidated.

In our tertiary epilepsy center, 84 patients with psychotic symptoms during LEV usage and 100 controls without psychotic symptoms during LEV usage were selected. Patient records were reviewed including demographics, medical history, antiepileptic drug use, and cognitive abilities. Univariate comparisons were performed, and variables with p < 0.1 were selected for binary logistic regression analysis.

The total incidence of psychosis during LEV therapy in our population was 3.7%. The timing of psychotic symptoms was classified as postictal in 20 (19.8%), interictal in 14 (15.4%), postepilepsy surgery in 1 (1.1%), and unknown in 18 cases (19.8%). In 31 cases (34.1%), psychotic symptoms were classified as an antiepileptic drug-induced psychotic disorder (AIPD) as a result of LEV. In 7 cases (7.7%), AIPD occurred as a result of a different antiepileptic drug. A significant association was found between the experience of psychotic symptoms and status epilepticus (p = 0.002), a history of psychotic symptoms (p < 0.000), a history of psychiatric illness other than psychosis (p = 0.010), and concomitant phenytoin (PHT) usage (p = 0.044). Cotherapy with lamotrigine (LTG) was protective (p = 0.042). A separate analysis of controls and exclusively the 31 cases with LEV-induced AIPD yielded comparable results; a significant association was confirmed with status epilepticus (p = 0.021) and history of psychotic symptoms (p = 0.018), as well as with female gender (p = 0.047) and intellectual disability (p = 0.043).

Our retrospective study found that psychotic symptoms during LEV therapy were significantly associated with status epilepticus, a history of psychotic symptoms, a history of psychiatric illness other than psychosis, and concomitant PHT usage, whereas concomitant LTG usage was protective. Psychotic symptoms specifically as an adverse drug reaction to LEV were significantly associated with female gender, intellectual disability, status epilepticus, and a history of psychotic symptoms.