BACKGROUND:
Health is influenced by social conditions and determinants that impact quality of life, such as age group, religion, and educational level. In the post–COVID-19 period, the presence or absence of symptoms and sequelae has distinct repercussions on the mental health domain, manifesting differently according to these social determinants. Therefore, this study aimed to verify the existence of an association between age group, religion, and educational level of Brazilians in post–COVID-19 conditions and the mental health domain, as assessed by the Short Form Health Survey-36 (SF-36).

METHODS:
An exploratory, cross-sectional, quantitative study conducted across all Brazilian states, with a sample of 854 participants. Data collection was carried out using the Software for Monitoring People with COVID-19, which included an instrument for characterizing individuals in post–COVID-19 conditions and the SF-36, an instrument that assesses quality of life based on eight domains; only the mental health domain was considered in this study. The study was approved by the Research Ethics Committee under opinion No. 6,709,120.

RESULTS:
In the mental health domain, statistically significant associations were observed with age group in both groups: participants with symptoms and sequelae (p=0.001) and those without symptoms and sequelae (p=0.010). Religion showed a significant association in both groups: participants with symptoms and sequelae (p=0.012) and participants without symptoms and sequelae (p=0.002). Educational level showed a significant association only in the group without symptoms and sequelae (p=0.005), with a progressive increase in scores according to higher levels of education.

CONCLUSIONS:
Mental health in the post–COVID-19 context is intrinsically linked to age group and religious beliefs, while educational level acts as a positive predictor of mental health in the Brazilian population.