This study evaluated the prevalence of substance use among students from a medical school in São Paulo, Brazil, during the COVID-19 pandemic. After the COVID-19 outbreak, we observed decreased use among students who reported less than once weekly use of substances and maintained use among students who reported weekly drug use. Finally, we compared the consumption rates between genders and academic years to identify which students were more prone to substance use.

The rate of substance use in our sample was higher than that among the general population of the same age ²⁶ and general university students in Brazil. ²⁷ Notably, cannabis is now the second most used drug among medical students, consistent with the more general trend observed among high school students in the United States ²⁸ and elsewhere. Additionally, the way cannabis is seen or used among medical students may influence the detection of substance use problems among patients in their future medical practice, as physician experience with drugs may affect how they perceive these problems. ²⁹ Physicians may also participate in developing future drug policies, and their attitudes as well as experiences with substances may influence their roles.

Tobacco use has almost doubled in the last 19 years when current data were compared to those obtained in the same sample in 2001. ²² This was unexpected as Brazil has a very efficient program to control smoking, ³⁰ with national rates continuously decreasing. Still, although other studies did not observe a similar increase, ³¹ consumption rate was similar to that observed among general university students in Brazil. ³² Alternative tobacco products (i.e., little cigars and cigarillos, e-cigarettes, and hookah), with potential appeal to the youth, may be associated with increased tobacco consumption among our population. ³³ Moreover, data showed that tobacco users in the last year had worse self-evaluated academic performance, and more severe depression symptoms measured by the PHQ-9 scale. The literature demonstrates a significant association between smoking and depression risk ³⁴ as well as symptoms. ³⁵ Additionally, a study conducted among Canadian medical students showed an association between current tobacco use and higher psychological distress. This study suggests that substance use may be a coping mechanism to deal with stress and the risk of burnout. ³⁶ This may also be the case of students from our sample, and tobacco may serve as a proxy to detect psychologically vulnerable students.

Ecstasy and hallucinogen use in this study was much higher than that among the general population and other medical students; ^26,37 although there is a general trend observed in other countries of increasing use of those substances. ^38–41 In our sample, during last year, cocaine was used by 7.6% of the students, a higher rate than that from previous studies investigating Brazilian medical students. ^37,42 Finally, amphetamine use was more frequent in our sample than in other studies, whereas alcohol and inhalant consumption rates were similar. ^32,37,43,44

Regarding the impact of the COVID-19 outbreak on the frequency of substance use, our findings suggest an overall reduction in consumption. There was a decrease in the number of students who reported “less than once a week” use of alcohol, tobacco, cannabis, cocaine, inhalants, hallucinogens, and ecstasy. On the other hand, the frequency of students who used drugs “once or more than once a week” remained constant during the COVID-19 pandemic. Social situations, such as parties where exposure to these substances occur, stopped happening after the pandemic started, which may have led to a decrease in substance use among infrequent users. In contrast, for higher-frequency users, our findings did not show a significant difference after the advent of the pandemic. This might be due to these students making use of these substances irrespective of social gatherings. Other studies evaluating the effects of the pandemic on substance use have reported similar findings, with a decrease in the overall consumption prevalence but an increase in the frequency of marijuana, alcohol, and tobacco use among users. ^19,45

We also analyzed the influence of gender and academic year on drug consumption. In our sample, men consumed more tobacco, ecstasy, and hallucinogens than women did. These findings are in line with other studies analyzing Brazilian and American populations. ^26,46 Regarding alcohol consumption among medical students, we found convergent use between genders, which was also observed in other non-medical student samples. ^22,47–49

A study conducted in 2001 in our setting reported greater use of amphetamines by women, ²² but this difference seems to be diminishing. At that time, amphetamines were mainly anorectic drugs (amfepramone, mazindol, and phenylethylamine) used by young women to reduce weight. These drugs were proscribed in Brazil in 2011. The currently available amphetamines in Brazil are mainly used for treating attention deficit hyperactivity disorder. Currently, non-medical use of amphetamines is primarily for academic performance improvement (“academic doping”), an increasingly common behavior among both genders, contributing to reducing the differences seen in previous studies. ^50–52

This study also showed a significant increase in the use of hallucinogens, amphetamines, cocaine, inhalants, marijuana, and ecstasy from the basic to clinical cycle. This is not surprising, given the age differences between cycles, and may reflect the natural progression of growing older and being exposed to novel experiences. ^22,44 However, besides aging, this finding could also be attributed to the increasing academic, professional, and financial stressors as medical students progress to their final clinical years. ^53,54 Therefore, medical school managers must be aware of this trend and implement preventive actions to avoid or mitigate it.

As medical schools are frequently linked to hospital settings, students should have ready access to mental healthcare. Unfortunately, the literature does not confirm this assumption. ^55,56 Moreover, in the medical student milieu, substance use policies are often punitive and stigmatized. ⁵⁷ Asking for emotional help can be seen as a weakness and career-threatening. ⁵⁸ Therefore, mental health care should be actively offered to this population.

This study had some limitations. First, our estimates were assessed in the context of the COVID-19 pandemic, following the implementation of social distancing measures. The effects of this confounder could not be discriminated within our sample, potentially influencing the drug use profile for the last year. However, the overall data shown in this study are compatible with those of other studies that evaluated substance use among medical students and studies conducted in the COVID-19 pandemic context. Second, participant responses may be subject to memory bias, which is a prevalent concern in retrospective studies. To minimize this effect, we used a standardized questionnaire to assess substance use during specific and objective periods. Additionally, despite being higher than the sample size estimates, our response rate (26.2 %) can be considered low and may reduce external validity. However, the distribution of respondents according to gender and academic cycle is consistent with the general proportion of students in our institution. Therefore, it was difficult to determine how the relatively low response rate affected the results. Moreover, our study is based on a convenience sample that may impair the representativeness of our results. This limitation is common in surveys for this type of population and has been observed in most studies on this subject. ^{2,31,40,50,51}