Long-Term Psychiatric Outcomes of Autoimmune Encephalitis

The authors aimed to characterize the long-term psychiatric outcomes and their predictors among survivors of autoimmune encephalitis (AE). In this retrospective cohort study, patients diagnosed as having AE between 2008 and 2023 at two academic medical centers (in New York City and Toronto) completed the Mini International Neuropsychiatric Interview 7.0.2 (MINI) and Profile of Mood States (POMS-2) to assess long-term psychiatric outcomes. Clinical characteristics were assessed for potential predictors of psychiatric outcomes. Bivariate analyses and univariate logistic regressions were conducted to assess the relationship between the predictors and the primary outcome. Overall, 42 participants (female, N=26, 62%; median age=37.5 years, interquartile range [IQR]=32.8 years) were assessed a median of 4 years (IQR=6 years) after an AE diagnosis. AE subtypes included anti-N-methyl-d-aspartate (33%), anti-leucine-rich-glioma-inactivated 1 (24%), anti-glutamic acid decarboxylase 65 (14%), and antibody-negative encephalitis (29%). In total, 71% of participants who completed the MINI met criteria for a DSM-5 diagnosis, and 56% were diagnosed as having a mood disorder. Thirteen participants (31%) reported above-average total mood disturbance on the POMS-2. Mann-Whitney U tests revealed that participants diagnosed as having a mood disorder self-reported significantly higher levels of confusion and bewilderment (z=-2.04, p=0.04) and depression and dejection (z=-2.24, p=0.03) and lower levels of vigor and activity (z=-2.62, p=0.01). AE survivors have a high prevalence of psychiatric comorbid conditions, with most being diagnosed as having a mood disorder and a significant proportion endorsing ongoing mood disturbance. Patients with a psychiatric history may benefit from closer psychiatric follow-up.