More than one in five adolescents will experience at least one mental health disorder requiring treatment; however, 75% of these adolescents will never receive mental health care, in large part due to the fact that there are far fewer trained clinicians than are necessary to address growing youth mental healthcare needs. Furthermore, the disparity between the number of available clinicians and those in need of mental health services is increasing. Between 2016 and 2020, the number of American children ages 3-17 diagnosed with an anxiety disorder or depression grew by 29% and 27%, respectively, whereas the American Psychological Association (APA) reports that the number of clinicians treating youth has continued to remain low, with only 4,000 out of 100,000 U.S. clinical psychologists identifying as child and adolescent clinicians. One possible solution to this issue of treatment access is to emphasize prevention and intervention strategies that can help reduce the number of young people who may develop mental health problems requiring more intensive care. However, even such prevention efforts have historically required large amounts of human capital for implementation. Fortunately, in recent years, digital mental health interventions have emerged as a potential solution to this issue as they offer scalable and cost-effective ways of preventing and intervening on mental health problems. Digital interventions requiring little-to-no professional support are especially appealing because they are easy to implement. Further, digital mental health interventions have been found to be efficacious for common mental health problems such as depression and anxiety, and some are effective for young people even in a single session.

The investigators propose one such intervention utilizing technology to address issues of access to mental health resources: Project THINK is a 30-minute self-guided digital intervention designed to teach children and adolescents how to change the way that they think. Specifically, Project THINK is based on the principles of cognitive restructuring, a core component of cognitive behavioral therapy, a gold standard treatment for internalizing disorders. Project THINK uses vignettes, interactive activities, and engaging graphics to teach youth a systematic strategy for assessing the presence of unhelpful thoughts and replacing them with more helpful ones. Although not yet formally tested in a randomized trial, Project Think has been used by hundreds of students, and feedback has been very positive.

Aim 1. In collaboration with U.S. middle schools, the investigators aim to conduct a randomized trial examining the efficacy of Project THINK relative to an active control condition, Project SHARE (i.e., Sharing Feelings)-which teaches users to identify their emotions and share them with trusted adults-on improving symptoms of mental health and well-being among adolescents. The investigators aim to recruit 1,625 participants in grades 5-10 (ages 10-16 years). According to a priori power analyses and after accounting for high expected attrition, this target sample size will provide sufficient power (1-β; 80%) to detect overall mean group differences and moderation effects of small effect size (.2; minimum N=788) using two-tailed tests with α = .05. The use of Project SHARE is appropriate in this context given that it has been used in past research studies and it has been found to be useful for young people, but it is not designed to target symptoms of psychopathology.

During a time selected by school partners (likely to be a wellness/physical education/gym class), participating students will choose whether they will assent to participate in the study. Only those participants whose parents have not elected to opt their child out of the study beforehand will be asked if they would like to participate. If students assent via an online form, they will be directed to an online battery of validated measures focused on mental health and well-being (e.g., Behaviors and Feelings Survey, and the Emotion Regulation Questionnaire--Child/Adolescent Version-Cognitive Reappraisal Subscale). Students will then be randomized to complete the Project THINK intervention or the Project SHARE active control online program; these two programs are similar in length and format. Immediately following completion of one of the two programs, participants will be asked to answer online demographic questions and to provide feedback on the intervention's helpfulness. All study procedures will be conducted via Qualtrics, and the investigators will conduct separate analyses for the subsample of students with elevated symptoms of psychopathology at baseline to assess the potentially different effects of Project THINK as a universal versus indicated prevention program.

Aim 2. The investigators aim to examine the effects of Project THINK relative to Project SHARE over time. Toward this end, participating students will be asked to complete a battery of measures at three follow-up timepoints: 1-month, 3-months, and 6-months after the baseline assessment and intervention administration. These follow-up measures represent a subset of the measures assessed at baseline (i.e., all measures assessed at baseline except demographic questions and feedback regarding intervention helpfulness). Once more, the investigators will conduct separate analyses for the subsample of students with elevated symptoms of psychopathology at the baseline assessment.

A secondary aim of this study is to interview a subset of student participants (10-30) from one of the partner schools. Following the one-month follow-up survey, the investigators will select an equal number of participants who are either 'responders' or 'not responders' to the Project THINK intervention. 'Responders' will be operationalized as those who were randomized to Project THINK and experienced a decline in internalizing symptoms (as measured by the Behavior and Feelings Survey). 'Non-responders' will be operationalized as those whose internalizing symptoms are not reduced. Through a semi-structured interview and thematic analysis in NVivo software, the investigators aim to identify patterns or themes that emerge in participants' experiences, and then examine whether these themes differ based on differential symptom trajectories. The investigators aim to examine the participants' recall of intervention content, comprehension of skills, perceived relevance of the skills, ways they used the skills following the intervention, as well as overall thoughts on the intervention and its delivery (sample questions are below). The participants who are selected for the interview will be excluded from the primary analyses at the 3 and 6-month follow-ups due to the potential interventional effects of the interview.