New challenges, stressors, and a loss of support often accompany the transition from adolescence to adulthood. Not surprisingly, transitional-aged youth (TAY) between the ages of 18-25 experience some of the highest rates of mental distress. However, access to mental health services diminish for TAY due to gaps in care when transitioning from pediatric to adult services. These challenges are exacerbated in rural communities, such as in Northwestern Ontario, where youth already access mental health services less frequently and face longer wait times than those in more urban areas. Limited access and extended waits can exacerbate symptoms, prolong distress, and increase the risk for adverse outcomes. Novel, innovative approaches are urgently needed to support TAY in Northwestern Ontario. In partnership with St. Joseph Care Group and Thunder Bay Counselling Centre, the investigators are evaluating the impact of a mental health app (JoyPop) as a tool for TAY waiting for mental health services. The JoyPop app was developed to support improved emotion regulation - a fundamental difficulty for youth presenting with mental health challenges. A two-arm randomized controlled trial (RCT) will be used to evaluate the effectiveness of the app compared to usual practice while TAY are waiting for mental health services.

Mental health services are less available and accessible in rural and northern communities than in urban areas. These issues are concerning as extended time on wait lists can exacerbate symptoms, prolong symptoms, prolong distress, and increase the risk for suicide, self-harm, and the need for hospitalization. Moreover, delayed access to mental health services negatively impacts treatment engagement, with non-attendance, decreased motivation, and reduced satisfaction with services frequently reported following prolonged wait times. A particularly vulnerable group in this context is Transitional-Aged Youth (TAY), individuals aged 18-25 who typically experience higher levels of mental distress in comparison to the general population. Given the imminent need for and reduced access to accessible mental health services for TAY in Northwestern Ontario, innovative solutions are needed.

In partnership with St. Joseph Care Group and Thunder Bay Counselling Centre, the investigators are evaluating the impact of a mental health app (JoyPop) as a tool for TAY who are waiting for mental health services. The JoyPop app was developed to support improved emotion regulation - a key difficulty for youth presenting with mental health challenges. Mobile mental health applications have the potential to increase accessible mental health support for TAY in Northwestern Ontario. Despite this promise of mobile mental health apps, significant gaps exist between the growing number of apps available in the public domain and empirical evidence of the beneficial impacts of apps for users. In particular, most apps that focus on emotion regulation have not been evaluated, are narrow in scope, or have only been evaluated among adult populations. The JoyPop app includes a broader focus, and this research is unique given its focus on rigorously evaluating the JoyPop app as a tool for treatment-seeking TAY in Northwestern Ontario.

Using a randomized controlled trial (RCT) design, the primary objective is to determine the effectiveness of the JoyPop app in improving emotion regulation among TAY (18- 25) who are waiting for mental health services as compared to usual practice (UP; monitoring those on the wait-list). The secondary objectives are to: (1) Assess change in mental health difficulties and treatment readiness between TAY in each condition to better understand the app's broader impact as a wait-list tool; (2) Conduct an economic analysis to determine whether receiving the app while waiting for mental health services reduces other health service use and associated costs; (3) Define the Minimal Clinically Important Difference (MCID) for the primary outcome measure; and (4) Assess TAY perspectives on the quality of the JoyPop app.

Inclusion Criteria:

• Youth must be on the wait-list for mental health services at St. Joseph's Care Group or Thunder Bay Counselling Centre and be between 18-25 years old.
• Eligible youth will also need to be available to attend a virtual or in-person orientation session.
• In order to download the JoyPop app, participants will need access to an iOS device (e.g., iPhone, iPad). Refurbished iPhones containing just the JoyPop app will be provided to participants to use for the duration of the trial if they do not have access to their own.

Given the nature of this trial, it will not be possible to blind participants to their allocation. As measures are self report, blinding of outcome measures is also not possible. Protect against bias will occur by blinding investigators to condition (i.e., only staff directly managing participants will be unblinded).