Mental Health and Cognitive Outcomes in Patients Six Months After Testing Positive Compared with Matched Patients Testing Negative for COVID-19 in a Non-Hospitalized Sample: A Matched Retrospective Cohort Study

We aimed to determine the mental health and cognitive outcomes at six months in people who had not been hospitalized with COVID-19 and who had tested positive or negative for COVID-19 in Eastern Ontario, Canada. Participants were matched 1:1 six months following their COVID-19 polymerase chain reaction test. X2, t -test, and Mann–Whitney U tests were conducted to compare self-report and observer-rated mental health and cognitive outcomes between the two groups. We also conducted an age and gender-adjusted logistic regression analysis to explore risk factors associated with depression, anxiety, and cognitive impairment among those who had tested positive for COVID-19. A total of 324 participants were enrolled ( n = 162 per arm). Overall, 40.7% of those in the COVID-positive group were men, with an average age of 37.9 (SD 13.2) years. In the COVID-negative group, 41.4% were men, with an average age of 36.7 (SD 12.8). There were no statistically significant differences in mental health outcomes between the groups. On cognitive testing, while 21% of the COVID-positive participants and 14% of the COVID-negative participants had scores indicating significant cognitive impairment, the difference between groups was not significant, though this warrants further investigation in future research. In non-hospitalized patients who have tested positive for COVID-19, there is no evidence of an increase in mental health disorders compared to people who tested negative. Any increases in mental health disorders during the pandemic may be the effect of social changes rather than an effect of the virus itself. The exception may be the cognitive changes in those who tested positive.