Mental health outcomes of encephalitis: an international web-based study

Encephalitis is associated with psychiatric symptoms in the acute and post-acute stages, and many survivors experience long-term sequelae. Despite this, the breadth and severity of mental health symptoms in survivors of encephalitis has not been systematically reported. We recruited adults who had been diagnosed with encephalitis of any aetiology to complete a web-based questionnaire assessing a wide range of mental health symptoms and disorders. In total, 445 respondents from 31 countries (55.1% UK, 23.1% USA, 2.2% low-and middle-income countries) completed the survey, with a median seven years since encephalitis diagnosis; 84.7% were diagnosed by a neurologist or infectious diseases doctor. Infectious encephalitis constituted 65.4% of cases, autoimmune 29.7%. Mean age was 50.1 years (SD 15.6); 65.8% were female. The most common self-reported psychiatric symptoms were anxiety (75.2%), sleep problems (64.4%), mood problems (62.2%), unexpected crying (35.2%), and aggression (29.9%). Rates of self-reported psychiatric diagnoses following encephalitis were high: anxiety (44.0%), depression (38.6%), panic disorder (15.7%), and post-traumatic stress disorder (PTSD, 21.3%); these rates were broadly consistent with the results of a validated self-report measure, the Psychiatric Diagnostic Screening Questionnaire (PDSQ). Severe mental illnesses such as psychosis (3.3%) and bipolar affective disorder (3.1%) were also reported. Many respondents also felt they had symptoms of disorders including anxiety (37.5%), depression (28.1%), PTSD (26.8%), or panic disorder (20.9%) which had not been diagnosed by a professional. Overall, rates of major self-reported psychiatric diagnoses and symptoms did not significantly differ between autoimmune and infectious encephalitis. In total, 37.5% of respondents had thought about suicide, and 4.4% had attempted suicide since their encephalitis diagnosis. Over half (53.5%) reported that they either had no, or substandard, access to appropriate care for their mental health. High rates of sensory hypersensitivities (>75%) suggest a previously unreported association between encephalitis and this distressing symptom cluster. This large international survey indicates that psychiatric symptoms following encephalitis are common, and that mental healthcare provision to this population may be inadequate, highlighting a need for increased provision of proactive psychiatric care for these patients.