University represents a period of transition where many students move away from home for the first time, requiring them to navigate the newfound independence and overcome unanticipated challenges when trying to make new friends and preserve existing relationships [1-3]. Students may find themselves suddenly dealing with new stressors without their previously relied upon support systems [4]. These stressors related to university life are combined with a period of development where the onset of many mental health and substance use disorders peaks [5,6]. Certain individuals may also be more likely to experience mental health problems in university based on various factors such as age, sexual orientation, ethnicity, and adverse childhood experiences [7]. Overall, this results in a population with a relatively high prevalence of mental health and substance use disorders [8,9]. For example, a study of college students across multiple countries found the 12-month prevalence of major depressive disorder, generalized anxiety disorder, and alcohol use disorder to be 18.5%, 16.7%, and 6.3%, respectively [9]. Despite the high prevalence of emerging mental health and substance use concerns, many university students do not seek help for these issues [10,11].

e-Interventions that promote self-management and link students to in-person services represent a promising means of addressing needs related to substance use and mental health issues. The potential of digital mental health interventions (eg, web-based programs and mobile apps) has been widely promoted, as they are often easily scalable and as beneficial as in-person therapies in promoting university students’ mental health [12-14]. Considering the high co-occurrence between mental health and substance use concerns [15], e-interventions are well positioned to offer low-barrier access to content supporting transdiagnostic approaches to interventions that acknowledge not only each individual concern but also their intersectionality. Existing digital interventions also address a range of challenges, including depression and anxiety [16], substance use [17], safety and risk management [18,19], and levels of severity (eg, subclinical mild to moderate symptom management and treatment for clinical conditions), and can be easily integrated into existing systems of care as a form of low-intensity, self-directed support [20].

To address these needs, a mental health and substance use mobile app called Minder was codeveloped with and for Canadian university students. This codevelopment process involved significant input from students through the creation of a Student Advisory Committee (SAC), usability testing via a virtual bootcamp (ie, individual user testing combined with a web-based survey), focus groups, and a pilot feasibility study [14]. By combining the prevention and early intervention components, the Minder app has been designed to target the general population of university students. This paper describes the protocol for a pragmatic 2-arm randomized controlled trial (RCT) to assess the effectiveness of the Minder mobile app in improving university students’ mental health and substance use outcomes.

Our primary objective is to test whether the Minder intervention improves mental health and substance use outcomes in a general population of university students. Our null hypothesis is that there is no difference between the intervention group, who are given access to a full version of the Minder mobile app, and the control group, who are given access to a restricted version of the app that sends reminder notifications about baseline and follow-up surveys but prevents access to all intervention components. We hypothesize that assignment to the intervention group will result in greater effects on the primary mental health and substance use outcomes. As such, we expect that participants assigned to the intervention group will be more likely to experience improvements in their mental health and substance use outcomes than those in the control condition.

The study is a single-blinded, 2-arm parallel assignment RCT with 1 intervention group and 1 control group (Figure 1). In the pretrial period (t−1), all students are screened for eligibility and invited to enroll in the study; enrolled participants then complete the baseline assessment survey (t0). After randomization, all participants enter into the trial (with full access or restricted access to the Minder app, depending on group assignment), concluding with a follow-up assessment survey at 30 days (t2; see Table 1 for participant flow through the study). In addition to the baseline and follow-up surveys, the intervention group will also complete an assessment at 2 weeks. The baseline and follow-up assessments contain all primary and secondary outcomes, whereas the 2-week survey contains only 2 primary outcome measures (Patient Health Questionnaire 9-Item [PHQ-9] and General Anxiety Disorder 7-Item [GAD-7]). All assessments are delivered through the app and typically require approximately 15 minutes to complete but may be completed at the participant’s own pace. The 30-day follow-up assessment may be completed for up to 14 days after the 30-day study period end point.

Upon the completion of the randomized controlled trial, participants in the control group will be offered access to the intervention for ethical reasons and will be followed (with those already in the intervention group) for up to 6 additional months as part of a separate period of natural observation not included in the formal RCT analyses. This trial was registered with ClinicalTrials.gov (NCT05606601) on November 4, 2022. The study will be conducted at the University of British Columbia (UBC), Vancouver Campus. All data will be collected in Canada.

Participant eligibility will be determined through an eligibility screener delivered on Qualtrics, a web-based survey platform, before registering for the study.

Participants must meet all the following inclusion criteria: student currently enrolled at the UBC Vancouver campus, aged ≥17 years, have access to and be able to use a smartphone with Wi-Fi or cellular data, and speak English. Students will be excluded based on an eligibility screening item assessing suicidality risk (“We want to make sure that this app is appropriate for you at this time. Do you have a current suicidal plan [i.e., a plan to end your life]?”). Anyone endorsing a current suicidal plan (ie, answering “yes”) will not proceed with the registration form and will instead be provided with a list of crisis resources.

Minder was codeveloped with input from 225 university students, including 44 student project team members. Codevelopment occurred through engaging students and volunteers on the project team, a SAC, and quantitative and qualitative studies (web-based survey, pilot feasibility RCT, and focus groups). Feedback was used to guide the app revisions following each of these processes, resulting in a final app that differed considerably from the initial prototype. Details of each component of these adaptation processes can be found in the study by Vereschagin et al [14].

Minder delivers a suite of evidence-based interventions that have been tailored to help university students improve their well-being and manage their substance use through 4 main components: Chatbot Activities, Services, Community, and Peer Coaching (Figure 2). The Chatbot Activities consist of an automated preprogrammed chatbot text and videos that draw primarily from cognitive behavioral therapy (CBT), given its demonstrated transdiagnostic efficacy in web-based intervention programs [21-24]. The Chatbot Activities also incorporate evidence-based content derived from metacognitive therapy, dialectical behavioral therapy, and motivational interviewing. These activities have been developed through collaboration with mental health professionals and university students so that the information can be presented in a way that is consistent with evidence-based practices and appropriate for this demographic. The Chatbot Activities were designed to support students on a range of topics and include content to manage mild to moderate distress and emotions and to help navigate general student life (eg, relationships, time management, and sleep hygiene). In addition, the content of the Chatbot Activities relates to the use of alcohol, cannabis, opioids, and stimulants, including general psychoeducation and motivational interviewing. These topics encapsulate many general skills included in CBT for managing emotions (eg, recognizing automatic thoughts) as well as additional topics highlighted by students through our codevelopment process as being more relevant to student well-being, such as transitioning to university. To increase the accessibility of the app, all activities that include video content have been closed-captioned in both English and French. Users have access to this entire range of content in the app and can choose to engage with any activities, regardless of their current mental health or substance use status. The Services component of Minder includes a validated psychosocial screening tool that provides users with tailored recommendations and resources based on their current needs and preferences [25]. It consists of a short survey with several categories (mental health, safety, substance use, abuse, housing, education, and sexual wellness) and an individually tailored list of relevant services that can be filtered by factors such as cost, availability, and delivery method. The Community component of Minder contains a searchable inventory of student groups or clubs at the university, which can be filtered according to the student’s interest. Finally, to support the use of the app, Peer Coaches (university student volunteers that have been trained by the research team’s clinicians) are available to help users navigate through different app components and provide nonclinical peer support. Once a Peer Coach is assigned, users can communicate with their coach through secure in-app texting or video calls in a synchronous or asynchronous manner. In this study, users in the intervention group will be offered Peer Coaches who will reach out to their assigned users twice during the study period (ie, at the beginning of the trial upon assignment and around the midpoint of the trial). Additional information on the development of Minder and its components can be found in the study by Vereschagin et al [14].

In addition to questions on the primary and secondary outcomes associated with the randomized controlled trial, participants in the intervention group will be asked a set of 12 additional questions on their experience using the Minder app at the end of the 30-day follow-up assessment. These questions will be used to inform the ongoing development of the app and use a combination of Likert-type and open text box responses to collect information on experiences using specific app components, reasons for using (or not using) features such as the Peer Coach, and any suggestions for improving key features such as the Minder chatbot.

The sample size calculation for a small effect assessed by the PHQ-9, GAD-7, and USAUDIT-C was calculated using an effect size defined by Cohen d=Δ/σ, where Δ is the group mean difference at the completion of the study and σ is the (pooled) within-group SD. For a small effect size (Cohen d=0.2), the sample size required to have 80% power at the level of significance P=.02 (0.05/3 primary outcomes) is 524 in each group. Assuming a 30% attrition rate, we require 748 participants in each group. To account for a conservative estimate of a small effect size and a 30% attrition rate, we estimate that a minimum of 748 randomized participants will be needed for each study group, totaling at least 1496 participants.

Sample recruitment will use a widespread, multifaceted approach that includes web-based and offline interactions with students as well as university faculty and administrators.

Web-based recruitment will occur through social media engagement via Facebook, Instagram, Twitter, and Reddit research laboratory or project pages or through recruitment material reposted by organizations represented on the SAC or UBC-affiliated groups (eg, student clubs and student government representatives). Web-based recruitment will also occur through the linked Student e-Mental Health survey, a version of the World Mental Health International College Student survey adapted for Canadian contexts and administered at UBC (approved by the UBC Behavioral Research Ethics Board under ethics ID #H19-02538 [34]). At the end of the linked survey, prospective participants will receive a message offering an opportunity to test a mental health and substance use app, and interested students will be redirected to a registration form for this study where they can consent and register to participate if qualified.

Offline recruitment will include in-person booths of student team members in frequented communal areas with high student traffic (eg, student union and main campus lawn or pathway) around the UBC Vancouver campus; placing recruitment posters in public places on campus; and distributing mini posters with QR codes to classes, students, and student groups on campus.

Student engagement will also occur through collaboration with select UBC faculty members and administrators. Specifically, members of the research team will attend in-person and web-based courses at the university to provide students with a short presentation about the study and will request that recruitment materials be included on course web pages and emails. In addition, student groups at the university will be contacted to share recruitment information with their members through emails and newsletters or to coordinate with study team members attending group meetings or events to directly share information about the study. Invitations to participate in this study will also be sent to students who have previously expressed interest in participating in research studies and asked to be contacted if study opportunities with the research laboratory became available.

Widespread signage will also be implemented through posters at on-campus bus stops and digital screens in on-campus buildings, as well as printed posters within buses designated for routes with direct connections to the university.

A study participant is defined as an individual who has completed the baseline survey and has been randomly assigned into either the control or intervention group. Participants are randomized using a stratified block randomization function built into the app. The randomization list for the built-in function was created using the web-based stratified block randomization list creator in the clinical trial software Sealed Envelope (Clerkenwell Workshop) [35]. To ensure that each arm of the randomized trial contains an equal number of participants endorsing a history of substance use, participants will be assigned to either group A (substance use: any medical opioid use, nonmedical opioid use, or nonmedical stimulant use) or group B (nonsubstance use), based on their answers to the opioid and stimulant use questions in the baseline survey. After being stratified into group A or group B, individuals are then automatically randomly assigned (via the randomization list embedded into the app) to either the control or intervention arm of the trial using a 1:1 ratio in blocks of 10.

Those randomized into the control group will receive a message saying that they will be asked to complete an additional survey at 30 days and will only receive full access to the app after that. During the 30-day study period, the control group participants will receive a restricted version of the app that only permits access to the following: an introduction video with several students providing a broad overview of the different aspects of the app and its potential value, several onboarding slides with a short summary of the main app components, and baseline and follow-up assessment surveys plus reminder notifications to complete those surveys. Participants randomized into the intervention group will receive immediate access to the full Minder app.

All participants will receive both email reminders and in-app push notifications to complete the assessment surveys. More specifically, after the initial email to prospective participants with instructions to download the app and complete the baseline survey (to be randomized), an email reminder to complete the baseline survey will be sent on day 7 and again on day 20 to those who have not yet completed it. Participants who have not completed the baseline after 1 month may receive an additional email reminder. Participants assigned to the intervention group will then receive an email and push notification to complete the 2-week survey. Participants in both the intervention and control groups will receive an email and push notification 30 days after baseline completion and a group assignment to notify them to complete the follow-up survey, along with a reminder email 5 days and 11 days later if the survey has still not been completed.

Participants in the intervention group will also receive general in-app push notifications on days 4, 18, and 24 to highlight the different features of the app. The intervention group also receives a push notification when they have a new in-app message from their assigned Peer Coach, either a scheduled message (at assignment and around the study midpoint) or a reply to an ongoing text conversation with the participant.

All data are collected in the app and stored on secure servers located in Canada. The research team will download all study data regularly (business days excluding statutory holidays) and monitor for any issues with data collection. Access to the data will be limited to the members of the research team. To ensure that participant information and privacy are protected, the Minder app backend will abide by the UBC Research Ethics Board guidelines and British Columbia’s Freedom of Information and Protection of Privacy Act. Participant data are collected using a unique study ID value within the system to ensure that survey response data and app use data remain separate from identifying information contained in the participant registration and remuneration documentation. The only exception will be if a participant elects to withdraw from the study and indicates their decision to have their data deleted; in this case, the data manager will use the unique study ID value to link their registration information with their survey response data and app use data and delete all their data from the system and all saved files.

There will be no stopping rules in this study—the anticipated benefits and unanticipated adverse effects are not life threatening and too small to merit such an approach. In addition, there will be no sequential analyses of the data: the analyses will commence at the end of the trial when the data manager provides the statistician with a blinded database for the analyses. Of note, data from the 2-week assessment completed by the intervention group will be removed from the data set used for the primary outcome analysis to maintain the blinding of the statistician.

This study was approved by the UBC Behavioral Research Ethics Board on January 6, 2022 (ethics ID: H21-03248). Any changes to the protocol will be submitted for approval to the UBC Research Ethics Board.

Consent will be obtained using a web-based UBC Qualtrics form before the email validation process (ensuring current student enrollment and only 1 study registration per student), which provides access to the app and baseline assessment survey.

Postsecondary students have been found to have high rates of mental health and substance use problems but many of these students do not access mental health or other professional supports [10]. e-Interventions have been shown to be effective among university students and may help address barriers to seeking support by providing tools that are easily accessible and can be scaled up for university campuses [16]. This manuscript describes the study protocol for a RCT to assess whether the Minder app is effective in improving mental health and substance use outcomes in a general population of Canadian university students. We hypothesize that individuals assigned to the intervention group will be more likely to experience improvements in mental health and substance use outcomes compared with individuals in the control condition. Additional secondary outcomes and analyses seek to inform potential mechanisms through which future studies can be conducted to better understand how to support the mental well-being of students and support the ongoing improvement of the Minder app as an effective digital mental health tool.

Although many similar e-interventions have experienced large loss to follow-up and poor participant engagement, the incorporation of Peer Coaches for each participant in addition to well-spaced reminders to return to the app and complete baseline and follow-up surveys are expected to improve app engagement and reduce loss to follow-up. It is also important to note that this intervention was designed for use in the general population with mild symptomology so recruitment may be challenging as these students may be less interested than a clinical population in participating in a mental health study. We have addressed this challenge by using a comprehensive set of recruitment methods to engage potential participants in the broader university population. The intervention also includes components relevant to all students, including content addressing general well-being and more clinically relevant content. Students who choose to participate in this study may also be more motivated than the general population to seek help or to improve their mental health or substance use concerns. This may impact their willingness to participate and responses to self-report surveys, which may lead to reporting bias; however, we believe that these biases will not differ across the surveys or between intervention and control groups. Moreover, mental health and substance use concerns are high among university populations, with a large fraction experiencing psychological distress; therefore, a study sample reporting a range—including elevated levels—of mental health or substance use concerns is representative of students’ functioning, which supports the generalizability of the results to the broader student population. In addition, participants in the intervention group will be unblinded, which could lead to biased self-reports of mental health symptomology related to placebo effects and social desirability. Although our use of standardized assessments completed via nonidentifiable web-based surveys should help mitigate some of these risks, it will be important to address this limitation in future studies on the Minder app by incorporating a sham or placebo control in future trials and examining the cognitive mechanisms associated with targeted outcomes.

Despite these limitations, the findings from this trial will inform the ongoing refinement of the Minder app. One key aspect of the Minder app that separates it from other similar tools is its extensive codevelopment process with students, especially in the development of content that is presented in a chatbot manner that is more interactive than other modular, web-based CBT interventions. It is designed to support a general population of students across many potential topics, whereas many existing tools target specific issues (eg, depression or anxiety). Thus, by designing a tool that can be used by all students, we hope to provide a suite of interventions (eg, from time management to managing emotions) that builds resilience across a range of conditions and improves the well-being of students as they face the many challenges associated with postsecondary education and young adulthood. This includes the tailoring and ongoing improvement of content using focus groups and continued engagement with specific groups of university students who may have more unique university experiences, including international students; lesbian, gay, bisexual, transgender, queer, 2-spirit, intersex, asexual, and similar minority (LGBTQ2IA+) students; and Indigenous and other racialized students. Through further analyses of app use data and subgroup analyses, we hope to identify areas of particular interest and need to help us better understand how to improve and scale up the delivery of the app to other student populations.