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

Abstract

Background Evidence for the associations between mental illness and the likelihood of a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test result and the clinical outcomes of COVID-19 is scarce. We aimed to investigate these associations with data from a national register in South Korea. Methods A nationwide cohort study with propensity score matching was done in South Korea using data collected from the Health Insurance Review and Assessment Service of Korea. We defined mental illness as present if one of the relevant ICD-10 codes was recorded at least twice within 1 year for an outpatient or inpatient. Severe mental illness was considered as non-affective or affective disorders with psychotic features. We included all patients aged older than 20 years who were tested for SARS-CoV-2 through services facilitated by the Korea Centers for Disease Control and Prevention, the Health Insurance Review and Assessment Service of Korea, and the Ministry of Health and Welfare, South Korea. We investigated the primary outcome (SARS-CoV-2 test positivity) in the entire cohort and the secondary outcomes (severe clinical outcomes of COVID-19: death, admission to the intensive care unit, or invasive ventilation) among those who tested positive. Findings Between Jan 1 and May 15, 2020, 216 418 people were tested for SARS-CoV-2, of whom 7160 (3·3%) tested positive. In the entire cohort with propensity score matching, 1391 (3·0%) of 47 058 patients without a mental illness tested positive for SARS-CoV-2, compared with 1383 (2·9%) of 48 058 with a mental illness (adjusted odds ratio [OR] 1·00, 95% CI 0·93–1·08). Among the patients who tested positive for SARS-CoV-2, after propensity score matching, 109 (8·3%) of 1320 patients without a mental illness had severe clinical outcomes of COVID-19 compared with 128 (9·7%) of 1320 with a mental illness (adjusted OR 1·27, 95% CI 1·01–1·66). Interpretation Diagnosis of a mental illness was not associated with increased likelihood of testing positive for SARS-CoV-2. Patients with a severe mental illness had a slightly higher risk for severe clinical outcomes of COVID-19 than patients without a history of mental illness. Clinicians treating patients with COVID-19 should be aware of the risk associated with pre-existing mental illness. Funding National Research Foundation of Korea.

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

“… 14 Nevertheless, we interpret this finding cautiously, as a Korean study found no association between psychiatric diagnosis and COVID-19 diagnosis, albeit in a much smaller sample and with less matching. 15 Possible explanations for the association include behavioural factors (eg, less adherence to social distancing recommendations) and residual socioeconomic and lifestyle factors (eg, smoking) that are not sufficiently captured by the available data in any of the studies. It could also be that vulnerability to COVID-19 is increased by the pro-inflammatory state postulated to occur in some forms of psychiatric disorder or be related to psychotropic medication.…”

“… 14 However, a Korean study found no such associations, except for patients with schizophrenia. 15 Reliable estimation of a possible increased risk of COVID-19 among patients with psychiatric illness requires large, well-controlled cohort studies.…”

Relationship between physical and mental health comorbidities and COVID-19 positivity, hospitalization, and mortality

“…In addition to the increased risk that pre-existing physical health conditions create for COVID-19 and related outcomes, emerging evidence shows that pre-existing mental health conditions may also confer significant risk for infection as well as increasing risk for hospitalization and mortality among positive screens ( Wang et al., 2020 ; Brown et al., 2020 ), however findings remain mixed. For example, initial evidence from South Korea examined the risk of COVID-19 infection and severity of outcomes across a nationwide cohort and found that pre-existing mental health conditions did not significantly increase risk for infection and there was a marginal increased risk for severe outcomes ( Lee et al., 2020 ). Conversely, evidence that became available as of November 2020 is demonstrating that individuals with pre-existing and recently diagnosed mental health conditions have a higher risk of infection, higher risk of hospitalization after infection, and an increased risk of mortality compared to individuals without diagnosed mental health conditions ( Wang et al., 2020 ).…”

Antihistamine and cationic amphiphilic drugs, old molecules as new tools against the COVID-19?

“…Among possible options, psychotropic drugs have been considered as possible prevention strategies. Indeed, given the numerous factors which might increase the risk of having a severe COVID in patients with psychiatric disorders, it is surprising that the initial prevalence of COVID, during the first wave and based on the first-published reports, was apparently similar or only slightly higher in patients with mental illness compared to the general population [ 1 , 2 ]. As some authors have recently suggested, this could be indicative of a prophylactic effect against SARS-CoV-2 shared by psychoactive agents commonly used to treat psychiatric patients [ 3 , 4 ].…”