United States: Severe cases of COVID-19 have been closely linked to an increased likelihood of depression and significant mental disorders in the months following infection, particularly among those who remained unvaccinated, according to a comprehensive cohort study that encompassed over 18 million individuals in the United Kingdom.
When compared to periods preceding COVID-19 infection or to individuals who never contracted the virus, those hospitalized due to COVID-19 exhibited markedly higher risks for depression within the first four weeks post-admission. This trend was observed across three distinct periods: the pre-vaccine era (adjusted hazard ratio [aHR] 16.3, 95% CI 15.6-17.0), among unvaccinated individuals (aHR 15.6, 95% CI 13.9-17.4), and in vaccinated individuals (aHR 12.9, 95% CI 12.0-14.0) during the vaccine era. The risk of depression persisted at an elevated level for up to a year in all three cohorts, according to MedPage Today.
Likewise, heightened risks for severe mental illnesses were documented among patients who were hospitalized in the four weeks following a COVID diagnosis. These findings were reported by Jonathan Sterne, PhD, of the University of Bristol in England, and colleagues in the journal JAMA Psychiatry:
– Pre-vaccine era: aHR 9.71 (95% CI 8.80-10.7)
– Unvaccinated: aHR 8.75 (95% CI 7.01-10.9)
– Vaccinated: aHR 6.52 (95% CI 5.36-7.93)
The study also revealed that the rates of most examined mental illnesses—such as anxiety, post-traumatic stress disorder, eating disorders, addiction, and self-harm—were notably higher during the first four weeks following a COVID hospitalization, according to MedPage Today.
“The most unexpected finding was that the association between COVID-19 and subsequent mental health issues seemed confined to severe cases of COVID-19 that required hospitalization,” Sterne shared with MedPage Today. “There was minimal correlation between non-hospitalized COVID-19 cases and subsequent mental health issues.”
Severe mental illness in this study was defined as a composite of schizophrenia, schizoaffective disorder, bipolar disorder, and psychotic depression.
The authors hypothesized that vaccination might mitigate the adverse effects of COVID on mental health. “Potential mechanisms include a reduction in systemic inflammation and psychological benefits associated with vaccination, such as diminished concerns about COVID-19 and increased social interaction,” they wrote.
“The primary advantage of COVID-19 vaccination lies in its substantial protection against severe cases of COVID-19. Consequently, our findings highlight the critical importance of COVID-19 vaccination, especially among groups at the highest risk for severe outcomes,” Sterne emphasized, as per MedPage Today.
“Severe mental illnesses are linked to increased healthcare needs and long-term adverse effects, thus long-term monitoring for the onset of new mental health issues among patients hospitalized due to COVID-19 may be warranted,” he added.
Regardless of whether patients were hospitalized, during the pre-vaccine era, the overall risk of depression within four weeks post-infection was 93% higher (aHR 1.93, 95% CI 1.88-1.98) compared to periods before infection or among those without COVID. The overall risk of developing severe mental illness was 49% higher (aHR 1.49, 95% CI 1.41-1.57). For unvaccinated individuals, the overall risks of depression (aHR 1.79, 95% CI 1.68-1.90) and severe mental illness (aHR 1.45, 95% CI 1.27-1.65) remained elevated.
The incidence of depression up to 28 weeks post-infection and the occurrence of severe mental illness over all time periods were greater in individuals aged 60 years and older. This may reflect an increased risk for severe disease and heightened anxiety about severe outcomes, the authors suggested, as per MedPage Today.
Notably, the incidence of mental illnesses remained elevated for over 28 weeks following a COVID-19 diagnosis. The estimated excess risk of depression at 28 weeks post-infection was 1,033 per 100,000 people in the pre-vaccine era and 1,008 per 100,000 in the unvaccinated group, while the risk among vaccinated individuals was significantly lower, at 451 per 100,000.
A similar trend was observed for severe mental illness at 28 weeks, with an estimated excess risk of 235 and 209 per 100,000 in the pre-vaccine era and among the unvaccinated, respectively, compared to 53 per 100,000 in the vaccinated cohort.
The study examined data from three cohorts during the pre-vaccine (January 2020 to June 2021) and vaccine eras (June to December 2021; the Delta variant period):
– 18,648,606 adults during the pre-vaccine era, of whom 1,012,335 had a confirmed COVID diagnosis
– 14,035,286 vaccinated adults, of whom 866,469 had a confirmed COVID diagnosis
– 3,242,215 unvaccinated adults, of whom 149,745 had a confirmed COVID diagnosis
Reportedly, the average ages of the pre-vaccine and vaccinated cohorts were 49 and 53 years, respectively, with approximately half being female. The unvaccinated cohort had an average age of 35 years, with about 42 percent being female. COVID diagnoses were confirmed via test results, general practitioner records, or hospital and death records.
The authors acknowledged several limitations of the study. Unvaccinated individuals might have been less inclined to test for COVID or utilize healthcare services, potentially leading to an underestimation of effects. Conversely, individuals diagnosed with COVID and subsequently hospitalized might have been more likely to be diagnosed with a mental illness in a hospital setting. Additionally, it is possible that the observed mental health effects were not unique to infection with SARS-CoV-2.