Saudi Arabia Mental Health Surveillance System (MHSS): mental health trends amid COVID-19 and comparison with pre-COVID-19 trends.

: The impact of the COVID-19 pandemic on populations' mental health has started to emerge. : To describe the mental health trends of the risk of major depressive disorder (MDD) and generalized anxiety disorder (GAD) between May and August 2020. It also compares the results with pre-COVID-19 results and identifies risk factors associated with increased likelihood of being at risk of MDD and GAD. : This study utilizes repeated cross-sectional design, at national-level coverage of mental health screenings via computer-assisted phone interviews conducted in four waves monthly (between May and August 2020). Arabic-speaking adults from Saudi Arabia were recruited via a random phone list. The questionnaire includes the Arabic version of the Patient Health Questionnaire (PHQ-9) and the General Anxiety Disorder-7 (GAD-7). Pre-COVID-19 comparison was done using the PHQ-2 score to allow for comparison with a previous and similar national study conducted in 2018. : Across the four waves, 16,513 participants completed the interviews, with an overall response rate of 81.3%. The weighted national prevalence of people at risk of MDD was 14.9% overall, and 13.8%, 13.6%, 16.8%, and 15.3% in Waves 1, 2, 3, and 4, respectively. The weighted national prevalence of people at risk of GAD was 11.4%, overall, and 10.9%, 10.7%, 12.4%, and 11.7% in Waves 1, 2, 3, and 4, respectively. The weighted national proportion of individuals who were at risk of MDD and GAD at the same time was 7.4% overall. The risk of MDD on PHQ-2 increased by 71.2%, from 12.5% in 2018 to 21.4% in 2020. : The risks of MDD and GAD in this study are relatively high. These results can help decision makers to understand the impact of the COVID-19 pandemic on the population's mental health and the most-impacted subgroups.