Depression is a highly prevalent and disabling mental health problem. One way of preventing depression is to stop it before it happens through effective self-management. Working with potential users, a coach-guided, personalized depression risk communication tool (PDRC) was developed for sharing information about individualized depression risk, risk profile (risk factors present), potential risk reduction and evidence-based self-help strategies. It is anticipate that the PDRC will greatly motivate users to actively engage in self-help and help seeking, leading to a reduced risk of depression. The proposed study will recruit 500 male and 500 female adults who are at high risk of having depression across Canada, and randomly allocate them into the intervention and control groups. Participants will be followed for 12 months. The data of the trial will allow us to answer the questions: (1) Can the coach-guided PDRC reduce the risk of depression? (2) Does the intervention motivate people to actively engage in evidence-based self-help and help-seeking behaviors? (3) For whom the intervention works best? and (4) what are the costs and potential savings associated with the intervention? If successful, this project will offer a novel and effective tool for early prevention of major depression in the Canadian general population, help us understand how it works and the cost-effectiveness of implementing such a tool in the community from the economic perspective.

Background and importance:

Depression is a highly prevalent and disabling mental health problem. One cost-effective way of reducing the disease burden associated with depression is selective prevention, i.e., identifying individuals who are at high risk of depression, and intervene before it happens. The investigators developed the first sex-specific multivariable risk predictive algorithms (MVRPs) for major depressive episode (MDE) using data from over 10,000 Canadians. Using the MVRP as the foundation and working with future users, the investigators developed a coach-guided personalized depression risk communication tool (PDRC) for sharing information about individualized depression risk, risk profile (risk factors present), potential risk reduction and self-help strategies. It is anticipate that the coach-guided PDRC will greatly motivate users to actively engage in self-help and help-seeking, leading to a reduced risk of depression in the population.

Goals/Research Aims:

The aims of the proposed randomized controlled trial (RCT) are to evaluate the impacts of the coach-guided PDRC on: (1) the risk of MDE at 12 months, (2) self-help and help-seeking behaviors, (3) the severity of depressive symptoms, and to examine (4) the moderation effect by self-efficacy and (5) the cost effectiveness of the coach-guided PDRC.

Methods/Expertise:

The proposed RCT has two arms: (1) intervention group, receiving the coach-guided PDRC; (2) control group, receiving personalized depression risk information. The study population are male and female adults in the community who are at high risk of having an MDE. Because the tools (MVRP) for estimating the risk of having an MDE are sex-specific, the recruitment and the randomization will be conducted in males and females separately. The investigators plan to recruit and follow 500 male and 500 female adults who are at high risk across Canada random digit dialing method and social media and poster advertisement.

The participants will be assessed at baseline, 3- and 12-month to ascertain short-term and mid-term effects. Data will be analyzed in males and females, separately, controlling for the effects of covariates which include gender and gender role related variables. The investigators will examine how the intervention influences the changes in self-help and help seeking behaviors and in depressive symptoms, whether the intervention effect differ by levels of self-efficacy, and if the economic gain exceeds program-related cost. Following the CONSORT guidelines, the investigators will perform both complete case and intent-to-treat analyses based on randomization. The research team has the needed expertise for conducting the proposed RCT, including psychiatry, epidemiology, biostatistics, health economics, risk communication and large RCTs.

The expected outcomes:

In aim 1, it is expected that participants who receive the coach-guided PDRC will have a significantly lower risk of developing MDE over 12 months than those in the control group. It is expected that the intervention will significantly enhance participants' self-help and help-seeking behaviors (aim 2) and reduce depressive symptoms (aim 3). In aim 4, it is expected to observe that the intervention effect is greater in those with higher level of self-efficacy. Finally, the intervention will achieve preferable cost and saving ratio (aim 5). If successful, this coach-guided PDRC can be a novel and cost-effective program for selective prevention of depression in the Canadian general population.

Inclusion Criteria:

• no MDE at baseline, or full remission for 2 months for those who had a past MDE (see below the question).
• Aged 18 and 65 years.
• At high risk of MDE based on the depression risk calculators (predicted risk of 6.5%+ for males and 11.2%+ for females), which represent the top two deciles of male and female populations in Canada.
• Agreement to be contacted for follow-up assessments, and
• no language barriers to English or French

Exclusion Criteria:

individuals who

• cannot provide informed consent,
• do not agree to be followed,
• cannot communicate in English and French, or
• report suicide behaviors (score >0 on item 9 of the Patient Health Questionnaire (PHQ-9)).

Depending on the nature of request.

The follow-up assessments will be conducted at the PI's telephone interview laboratory. Over the study period, investigators will be blinded to participants' group status. The survey firm interviewers who conduct baseline assessment and randomization, will not be involved in follow-up interviews. The interviewers who conduct the follow-up interviews will not have access to participants' group status. The coaches will not be involved in follow-up assessments. Given our description of study objectives, participants may know their group status. After the 12-month interview, group status will be linked with interview data by study identification numbers.