IntroductionOlder adults are at an increased risk of contracting illnesses during outbreaks such as the COVID-19 pandemic. Additionally, they have greater vulnerability to negative mental health outcomes as a consequence of public health restrictions that contribute to social isolation. Recent reviews have focused on the mental health effects of the pandemic on patients with COVID-19, healthcare workers (HCW), and the general population. Data on mental health outcomes in geriatric populations have emerged over the last 12-18 months, but no reviews regarding the prevalences of psychiatric symptoms have yet been published. We reviewed population-based studies that focused on the development of clinically significant psychiatric symptoms in the older adult general population aged 50+ years, to yield overall prevalence rates of post-traumatic stress, depression, anxiety, stress, insomnia/sleep disturbances, and psychological distress symptoms in older adults during the COVID-19 pandemic globally.MethodsOur review was conducted based on the PRISMA Extension for Scoping Reviews Checklist. We searched PubMed and preprint servers (https://www.medrxiv.org/) from January 1, 2020 to November 5, 2021, and conducted secondary searches using Web of Science from January 1, 2020 to November 30, 2021 and by reviewing the reference list of relevant studies. Studies were included in the review if they (i) focused on mental health outcomes during the COVID-19 pandemic; (ii) used validated measures of psychological or psychiatric symptomatology; (iii) comprised mainly of the general older adult population (aged 50 years+); and (iv) reported quantitative outcomes of prevalence (expressed as the percentage of participants exceeding the normal cut off for that measure). Excluded were (i) opinion papers or commentaries; (ii) studies that reported qualitative data; (iii) studies with samples mainly consisting of HCW, participants with confirmed or probable COVID-19 infection, hospitalized patients, or patients with a disease or condition; and (iv) clinical trials or intervention studies. To yield summary statistics, prevalence rates and sample sizes were pooled across studies.ResultsThirty-eight full-text published articles met inclusion criteria. Across all studies, 41% of the participants were male, and all participants were above 50 years old. All studies employed cross-sectional designs and the majority used on-line survey tools. Specifically, 23 were on-line, 12 used telephone, 1 in-person, 1 through mail, and 1 used both on-line and telephone. 6 studies were based in North America while the remaining studies originated from across the globe (1 from Africa, 1 from Australia, 22 from Europe, 3 from Asia, 3 from South America, and 2 from a global sample). In a pooled sample size of 57,933 across all 38 studies, 28.3% experienced post-traumatic stress, 24.9% experienced depression, 19.4% experienced anxiety, 10.3% experienced stress, 44.1% experienced insomnia/sleep disturbances, and 17.0% experienced psychological distress, exceeding the normal cut-off.ConclusionsOverall, nearly one-quarter, or 24%, of older adults have experienced clinically significant psychiatric symptoms in the form of post-traumatic stress, depression, anxiety, stress, insomnia/sleep disturbances, or psychological distress during the COVID-19 pandemic. These rates appear lower than those of the general non-geriatric adult population based on existing studies. However, it should be noted that rates of psychiatric symptoms were established to be lower in older adults compared to their younger counterparts, even pre-pandemic. A limitation of the current literature is that the cross-sectional design of available studies does not allow us to determine whether the prevalence rates reported in older adults are increased from pre-pandemic baseline rates. Further, the reliance on online survey tools in the majority of studies may have resulted in under-reporting of psychiatric symptoms, since older adults without access to the internet may be more socially isolated during the COVID-19 pandemic than those who are able to remain in contact with family and friends using social media and video conferencing tools. Third, it should be noted that the measures employed in population studies were originally intended for screening purposes, rather than to establish a psychiatric diagnosis. Future studies comparing baseline pre-pandemic rates of psychiatric symptomatology with those following the onset of the COVID-19 pandemic are needed to determine the effect of the pandemic on mental health in older adults.This research was funded byThe study was funded by the Ontario Ministry of Health and Long-Term Care Alternative Funding Plan. The funders had no role in the design of the study, analysis, or preparation of the manuscript.