Long-Term Psychiatric Symptoms in Autoimmune Encephalitis Remission

Objective To identify the prevalence of self-reported symptoms of depression and anxiety among patients in remission from autoimmune encephalitis (AE). Background Although prior studies have found a high prevalence of residual cognitive deficits among patients in remission from AE, there is a paucity of data on long-term psychiatric outcomes for this patient population. In normal populations, median Patient Health Questionaire-9 (PHQ9) and General Anxiety Disorder-7 (GAD7) scores were reported to be, respectively, around 3 and 2, with prevalence of depressive and anxiety symptoms on these questionnaires reported as around 24% and 23%. Design/Methods Retrospective cross-sectional cohort study at a tertiary center AE clinic between 2012-01-01 and 2021-12-31. Patients were contacted via phone or regular follow-up and completed the PHQ9 and GAD7. Results Forty-one patients were contacted; 29 responded (71%) and were included. Seventeen (59%) were female. Median age was 32.5 years (range 5-77). Autoantibody results were N-methyl-D-aspartate receptor (n = 14, 48%), negative (n = 7, 24%), leucine-rich glioma-inactivated 1 (n = 6, 21%), and contactin-associated protein-like 2 (n = 1, 3%). Median time from disease onset to questionnaire collection was 6.3 years (range 1.5-23.0). Ten patients (37%) were experiencing symptoms of depression as measured by the PHQ9, with six (60%) reporting moderate-to-severe symptoms. Median PHQ9 score was 3 (range 0-18). Six patients (22%) were experiencing symptoms of anxiety on the GAD7, with one (17%) reporting moderate-to-severe symptoms. Median GAD7 score was 2 (range 0-10). Eight patients (28%) reported a psychiatric history prior to the onset of AE, which was associated with increased PHQ9 scores (p = 0.04, Wilcoxon rank sum test). Conclusions The prevalence of self-reported depressive and anxious symptoms in this cohort in remission from AE was similar to general populations. Patients with a psychiatric history that preceded onset of AE had higher PHQ9 scores. These results may be affected by censoring bias and lower sensitivity of self-reported diagnostic tools.