Objective
This study investigated the incidence of suicidal ideation and its associated risk factors in the state of São Paulo in the Brazilian Longitudinal Study of Adult Health (Estudo Longitudinal de Saúde do Adulto [ELSA-Brasil]) cohort during the coronavirus disease 2019 (COVID-19) pandemic.

Methods
In a pre-pandemic ELSA-Brasil onsite assessment in 2016-2018 (wave 3) and a pandemic online assessment in May-July 2020 (wave COVID), we assessed suicidal ideation using the Clinical Interview Schedule-Revised (CIS-R). Single and multi predictor logistic regressions were performed using sociodemographic characteristics, household financial impact during the pandemic, presence of previous chronic diseases, alcohol abuse, adverse childhood experiences (ACE), living alone, and previous common mental disorders (CMD) as predictors. Incidence of suicidal ideation was used as outcome.

Results
Out of 4,191 participants in wave 3, 2,117 (50.5%) also answered the COVID wave. There was a threefold increase in suicide ideation, from 34 (1.8%) to 104 (5.6%) participants. In multiple predictor models, we found that previous CMD (odds ratio [OR] 7.17; 95% confidence interval [95%CI] 4.43 - 11.58) and ACE (OR 1.72; 95%CI 1.09 - 2.72) increased the odds of incident suicidal ideation. The sociodemographic predictors female sex, younger age, and low income were significant risk factors in the single predictor models only.

Conclusion
These findings underscore the importance of monitoring and supporting individuals who suffered ACE and have a history of mental health disorders. This is especially critical in times of heightened societal stress, such as the COVID-19 pandemic.