key: cord-0841543-px1thlv1
authors: Hirakawa, Hirofumi; Ishii, Nobuyoshi
title: Association between mental illness and COVID-19 in South Korea
date: 2021-02-19
journal: Lancet Psychiatry
DOI: 10.1016/s2215-0366(20)30539-3
sha: 214da2a45838f1f5a6133b1f30647ee950bde714
doc_id: 841543
cord_uid: px1thlv1

nan

We read with interest the article by Seung Won Lee and colleagues in The Lancet Psychiatry, 1 in which the authors examined the association between mental illness and testing positive for COVID-19 with data from a national register in South Korea. It was surprising that a diagnosis of a mental illness was not associated with an increased likelihood of testing positive for COVID-19, given that this opposed the results of recent research findings. Yang and colleagues 2 reported that preexisting psychiatric disorders are associated with an increased risk of COVID-19, based on data from the UK Biobank. Additionally, Taquet and colleagues 3 showed that a psychiatric diagnosis within the previous year was associated with a higher incidence of a COVID-19 diagnosis, based on data from the TriNetX Analytics Network in the USA. 3 We questioned why there were such different results. An interesting finding of Yang and colleagues was that the risk of COVID-19 differed based on preexisting ICD-10 psychiatric disorders. 2 The risk of COVID-19 was elevated in cases of depression, anxiety, substance misuse, and psychotic disorders; however, risk was not increased in cases of stress-related disorders. 2 In Yang and colleagues' Article, of the 50 809 people with prepandemic psychiatric disorders with COVID-19, 44·0% (n=22 352) had depression, 32·6% (n=16 573) had anxiety, 1·7% (n=872) had stress-related disorders, 46·5% (n=23 620) had substance misuse, and 2·8% (n=1431) had psychotic disorders. 2 Therefore, according to Yang and colleagues, preexisting psychiatric disorders were associated with an increased risk of COVID-19, reflecting the results of patients with depression, anxiety, and substance misuse. 2 Lee and colleagues defined mental illness, on the basis of the ICD-10, as non-affective psychotic disorders, affective psychotic disorders, anxiety-related and stress-related disorders, alcohol or drug misuse, mood disorders without psychotic symptoms, eating disorders, and personality disorders. 1 However, they did not mention the exact proportions of these diagnoses for the analysis. We considered that the differences in the proportions of psychiatric diagnoses might have affected the differing research findings, and we recommend that the authors mention the number of patients with each psychiatric diagnosis.

We declare no competing interests.

Association between mental illness and COVID-19 susceptibility and clinical outcomes in South Korea: a nationwide cohort study

Pre-pandemic psychiatric disorders and risk of COVID-19: a UK Biobank cohort analysis

Bidirectional associations between COVID-19 and psychiatric disorder: retrospective cohort studies of 62 354 COVID-19 cases in the USA