[An impact of the COVID-19 pandemia on the onset and course of mental disorders in elderly].

Objective: To study the impact of COVID-19 on the onset and course of mental disorders in hospitalized elderly patients.

Material and methods: We studied 67 inpatients, aged 50 to 95 years, with various mental illnesses in accordance with the ICD-10 criteria, who underwent COVID-19 from February 2020 to December 2021. Forty-six people were previously mentally ill, in 21 cases the disease developed for the first time.

Results: The group of primary diseased patients was dominated by depressive episodes (F32, (42.9%), including psychotic episodes (9.5%). In 28.6% of cases, organic disorders were diagnosed in the form of emotional lability (F06.6), organic depression (F06.3), mild cognitive impairment (F06.7) and delirium (F05.86). In 23.8% of patients, neurotic disorders were observed in the form of depressive reactions (F43), panic (F41.0) and generalized anxiety disorder (F41.1). In one case (4.8%), acute polymorphic psychosis with symptoms of schizophrenia (F23.1) was diagnosed. The diagnoses of the previously mentally ill group were: affective disorders (F31, F32, F33 - 45.7%); organic disorders, including dementia (F06.3, F06.7, F00.1, F00.2 - 26.1%); schizophrenia spectrum disorders (F25, F21, F22, F20.01 - 19.6%), and neurotic somatoform disorders (F45 - 8.7%). In the acute and subacute periods of COVID-19 (≤3 months), acute psychotic states (APS) developed in both groups of patients (in 23.3% and 30.4%, respectively) in the form of delirium, psychotic depression, or polymorphic psychosis. APS were more common in mentally ill patients with organic (50%) and schizophrenia spectrum (33.3%) disorders with a predominance of delirium. In the long-term period of COVID-19, mentally ill patients more often than primary diseased patients (60.9% and 38.1%) developed 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 degree of dementia in 15.8% of cases. APS were significantly associated (p<0.05) with the development of CI (0.567733), the age of patients (0.410696) and the presence of previous cerebrovascular insufficiency (0.404916).

Conclusion: The age-related features of the mental consequences of COVID-19 are the occurrence of APS in the acute period of infection and the deterioration of cognitive activity at a remote stage. The mentally ill, especially those of the organic and schizophrenia spectrum, were found to be more vulnerable to the effects of COVID-19. In them, the occurrence of APS was a risk factor for the development of dementia, while in primary diseased, affective and neurotic patients, CI was reversible or had the character of a mild cognitive disorder.