College students were considered to be a sensitive and special group, and their mental health seemed to be more troubled, as their vulnerability is exacerbated by their inability to adapt to the new environment of universities, higher education plans, and the insufficient identification and utilization of social resources (Acharya et al., 2018). Many studies had investigated the mental health problems of college students and explored the related influencing factors. They suggested that college students’ mental health was affected by academic education, psychological elasticity, stress level, and other factors (Torres et al., 2017; Acharya et al., 2018; Alqudah et al., 2021; Alyoubi et al., 2021).

In December 2019, unexplained pneumonia suddenly broke out, which had swept the globe in a short time (Galea et al., 2020). With numerous infected people appearing every day, the government took lockdown measures to control and prevent the serious epidemic (Pierce et al., 2020; Tran et al., 2020; Basheti et al., 2021; Fancourt et al., 2021). Some studies had reported that mental health was related to COVID-19. A cross-sectional study conducted in China shows that Chinese people’s anxiety, depression, and drinking levels are more significant than before, and their mental health status decreases during the outbreak of COVID-19 (Ahmed et al., 2020). Some studies have shown that anxiety and depression are common mental health problems faced by college students during COVID-19, and they are at a high risk level (Naser et al., 2020); similarly, research results show that college students are vulnerable to psychological problems during the pandemic of COVID-19 and isolation and distance learning has a significant impact on students’ anxiety levels (Alqudah et al., 2021); In addition to COVID-19 patients and medical staff, college students are another group of people who are particularly prone to mental health disorders during the pandemic. Even if not during the outbreak of COVID-19, college students are experiencing considerable anxiety and depression due to academic pressure (Deng et al., 2021). Some related meta-analyses also confirmed this, the prevalence of depression and anxiety among college students increased during the COVID-19 (Deng et al., 2021; Guo et al., 2021).

Compared with other higher education, medical education was regarded as one of the training programs with the highest academic and emotional requirements out of any profession (Azad et al., 2017; Quek et al., 2019; Zeng et al., 2019). This demand and pressure caused a negative impact on the medical students’ mental health (Basudan et al., 2017; Shao et al., 2020). School closures, online teaching, and the inability to complete hospital internships had changed the inherent training model of medical students (Abbasi et al., 2020; Byrnes et al., 2020; Farooq et al., 2020; Soled et al., 2020; Bilgi et al., 2021). The study of medical students of bezmialem vakif University shows that many students are deeply affected by the epidemic process, no matter how long they have studied in medical school, one of the main reasons is the interruption of educational activities (Bilgi et al., 2021). The challenges of COVID-19 to global medical students’ mental health were unknown, especially the pooled prevalence of depression and anxiety, although some researchers were concerned about medical students’ mental health during this special period (Liu et al., 2020; Nakhostin-Ansari et al., 2020; Gupta et al., 2021). However, available studies had varied widely in terms of countries, assessments, and sample sizes, and in addition, there had been considerable variations in the reported prevalence of depression and anxiety. Therefore, for future researchers to quickly grasp the depression and anxiety of medical students during the epidemic, to facilitate their further research, this meta-analysis was conducted.

We conducted this systematic review and meta-analysis to determine the prevalence of depression and anxiety in medical students over the world during the COVID-19 pandemic. In our study, we find that the pooled prevalence of depression and anxiety among medical students was 37.9%, 95% CI: 30.7–45.4%; 33.7%, 95% CI: 26.8–41.1%, more prominent relative to the general population and healthcare workers (Pappa et al., 2020; Castaldelli-Maia et al., 2021; Cénat et al., 2021; Raoofi et al., 2021; Sahebi et al., 2021; Santabárbara et al., 2021). This seemed to be consistent with the prevalence of anxiety reported by Quek et al. (2019) (33.8%, 95% CI: 29.2–38.7%). However, we found that the research they included had a heavy period, from 1998 to 2019, while the research we included was more concentrated. We inferred that an excessive period might have an impact on the pooled prevalence of anxiety. Another study reported that the prevalence of anxiety among medical students during the epidemic was 28%, which was lower than our conclusion (Lasheras et al., 2020). We found that their latest literature search time was August 26, 2020, although the epidemic situation had been partially controlled at that time, its influence still existed. Even in China, medical students deferred enrollment until October 1, 2020. Repeated signs of the epidemic situation and the fear of returning to school, the impact of these factors on the mental health among medical students needed to be considered. In addition, we also found that the prevalence of depression among medical students was relatively high during the COVID-19 compared with before (Puthran et al., 2016; Rotenstein et al., 2016).

Interestingly, when we performed a subgroup analysis based on the sample source countries, we found that the pooled prevalence of depression and anxiety among Chinese medical students was not prominent (28.7%, 95% CI: 20.3–38.0%; 24.3%, 95% CI: 15.7–34.0%). We further divided countries according to continents and conducted subgroup analysis. It was noted that the prevalence of depression was the highest in Europe (52.3%, 95% CI: 22.9–80.8%) and relatively low in Asia (36.2%, 95% CI: 27.6–45.3%). In terms of anxiety prevalence, Europe is at a low level (23.2%, 95% CI: 21.0–25.5%), and South America has the highest anxiety prevalence (49.0%, 95% CI: 36.6–61.5%). Research showed that rumors about the epidemic affected the mental health of citizens (Ahmed et al., 2020; Xiong et al., 2020), and the mental health of the population was also related to the nationwide epidemic control (Jiang, 2020). Limited outdoor activities, increased new cases and fear of the possibility to be infected were identified to impact mental health (Jiang, 2020; Wang et al., 2020c; Kaplan Serin and Doğan, 2021). In particular, the closure of schools and online teaching had brought unprecedented challenges to the education of medical students (Bilgi et al., 2021), and the effects of social distance and self-isolation might make students feel more vulnerable and lonelier, increasing depression and anxiety symptoms (Huang et al., 2020). Similarly, in some countries, medical students were limited to a clinical internship during the epidemic. Sudden changes impacted the traditional training mode of medical students (Abbasi et al., 2020; Keskin and Özkan, 2021). The impact of COVID-19 on psychological and mental health can be reduced by timely updating the relevant accurate information such as the number of new epidemic cases and the route of transmission (Wang et al., 2020a). Benefit from the rapid and effective measures taken by the Chinese government, the epidemic was quickly and effectively controlled and the public panic was reduced (Lau et al., 2020; Pan et al., 2020; Li et al., 2021).

Finally, we found that the prevalence of depression and anxiety in female medical students was higher than that in males, and some previous studies have reported a similar situation (Puthran et al., 2016; Quek et al., 2019; Alyoubi et al., 2021; Luo et al., 2021). Females seemed to be more vulnerable to mental health problems than males (Baxter et al., 2013; Qiu et al., 2020; Xiong et al., 2020; Kalkan Uğurlu et al., 2021), we speculated that it was related to females unique physiological and psychological factors: females are more likely to articulate their worries and emotions (Basudan et al., 2017; Lin et al., 2021). When we performed subgroup analysis according to the assessment tools, we found that different depression and anxiety assessment tools also brought different prevalence rates of depression and anxiety. Due to the diversity of sample sources and the high heterogeneity of subgroup analysis, we could not infer the impact of different assessment tools on the prevalence of depression and anxiety among medical students.

COVID-19 has a huge impact on mental health. An American study showed that the prevalence of depressive symptoms was more than 3 times higher during COVID-19 compared with before (Ettman et al., 2020). Economic turmoil, home quarantine and the uncertainty of COVID-19 cases had brought great stress to the people, accompanied by an increase in the level of anxiety and depression during the COVID-19 pandemic (Shehata et al., 2021). Studies have shown that strict government policies slow down the spread of COVID-19, but such interventions disrupt daily life and lead to adverse mental health outcomes, especially strict blockade measures and home confinement with unknown duration. Epidemiological monitoring and targeted intervention should be implemented in time to prevent further mental health problems (Rossi et al., 2020; Wang et al., 2020b; Ding et al., 2021). Personal exposure to COVID-19 is an important risk factor for increased anxiety and depressive symptoms during pandemic (Ding et al., 2021). The prevalence of anxiety was more significant in people who had infected with COVID-19 or knew someone who had experienced illness (Shabahang et al., 2021). In addition, less exercise and lack of social support can also lead to more anxiety and depression symptoms (Kong et al., 2020; Shah et al., 2021).

Although study had shown that the harm caused by COVID-19 pandemic to the overall mental health of the population will improve over time (Gallagher et al., 2021), epidemics and other health emergencies may lead to harmful and long-term psychosocial consequences, which cannot be ignored (Dong and Bouey, 2020). Even if the epidemic ends, its negative socio-economic consequences, such as work difficulties, may also have an adverse impact on the mental health of the population (Rossi et al., 2020). Without intervention and appropriate health and social policies, mental health problems will have serious adverse consequences. The government plays an important role in reducing the prevalence of anxiety and depression during COVID-19. The government’s decisive and rapid epidemic prevention measures can help to reduce the further spread of the COVID-19 and protect the mental health of the public (Wang et al., 2020b; Zhang et al., 2021c). In addition, family companionship can reduce anxiety and depression levels (Shah et al., 2021).

In conclusion, this systematic review and meta-analysis reported a relatively high prevalence of depression and anxiety. The prevalence of depression and anxiety was 37.9%, 33.7%, higher than that of the general population and healthcare workers. The prevalence varied in different countries. Researchers can further explore the differences and influencing factors of mental health among medical students with different cultural backgrounds.

The original contributions presented in the study are included in the article/Supplementary Material, further inquiries can be directed to the corresponding author.

QJ conducted the data analyses and wrote the manuscript. HH and HY conducted the literature search. YQ and HS conducted the study quality assessment. DY conducted the supervision, review, and editing. All authors approved the final manuscript.

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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