Effects of the COVID-19 Pandemic on the Occurrence and Course of Mental Disorders in Elderly People

Objectives. To study the impact of COVID-19 on the occurrence and course of mental illness in hospitalized elderly patients. Materials and methods. We examined 67 hospitalized patients aged 50–95 years with various mental pathologies diagnosed using ICD-10 criteria who had COVID-19 from February 2020 to December 2021. Of these, 46 patients were previously mentally ill, while 21 experienced first-onset mental disorders. Results. The group of first-onset cases was dominated by depressive episodes (F32) (42.9%), including psychotic episodes (9.5%). Organic disorders were diagnosed in 28.6% of cases, in the form of emotional lability (F06.6), organic depression (F06.3), mild cognitive impairment (F06.7), and somatogenic delirium (F05.86). Neurotic disorders were observed in 23.8% of patients, in the form of depressive reactions (F43) and panic (F41.0) and generalized (F41.1) anxiety disorders. Acute polymorphic psychosis with symptoms of schizophrenia was diagnosed (F23.1) in one case (4.8%). Diagnoses in the group of patients with previous mental illness were: affective disorders (F31, F32, F33) in 45.7%; organic disorders, including dementia (F06.3, F06.7, F00.1, F00.2) in 26.1%; schizophrenia spectrum disorders (F25, F21, F22, F20.01) in 19.6%; and neurotic somatoform disorders (F45) in 8.7%. In the acute and subacute periods of COVID-19 (≤3 months), the two groups of patients developed acute psychotic states (APS) in the form of delirium, psychotic depression, or polymorphic psychosis, in 23.3 and 30.4% of cases respectively. APS were more common in previously mentally ill patients with organic (50%) and schizophrenic (33.3%) spectrum disorders with a predominance of delirium. In the longer-term (>3 months) period of COVID-19, previously mentally ill patients also showed more frequent (60.9% and 38.1%) development of cognitive impairment (CI), especially in schizophrenic (77.8%) and organic (83.3%) disorders. CI developed twice as often after APS (89.5% and 39.6%, p < 0.001), reaching the level of dementia in 15.8% of cases. APS displayed significant associations (p < 0.05) with the development of CI (0.567733), patients’ age (0.410696), and the presence of cerebrovascular insufficiency (0.404916). Conclusions. Age-related features of the mental sequelae of COVID-19 included the occurrence of acute psychosis in the acute period of infection and deterioration of cognitive activity in the longer-term stage. Patients who already had disorders of the organic and schizophrenic spectra were more vulnerable to the effects of COVID-19. In this group, the occurrence of APS was a risk factor for the development of dementia, while in newly ill, affective, and neurotic patients, CI were reversible or amounted to mild cognitive disorder. © 2023, Springer Nature Switzerland AG.