Patients seeking mental health care and those being discharged from psychiatric units frequently express psychological distress. A lack of routine follow-up and tailored support during these critical stages of a patient's journey can weaken the patient's connection to the health care system, resulting in low adherence and dissatisfaction with treatment, and the need for more intensive therapies. These unfavourable outcomes may result in deterioration of the patient's mental health, readmissions, recurrent emergency department (ED) visits, and extended length of stay (LOS). The investigators propose implementing an add-on supportive text messaging service (Text4Support), developed using cognitive-behavioural therapy (CBT) principles to augment mental health support for patients accessing different degrees of psychiatric care in Nova Scotia. The primary objective is to investigate the effectiveness of Text4Support, compared to usual care, in improving clinical mental health outcomes and overall mental wellbeing among participants. Secondary objective is to examine the impact of Text4Support on health services utilization and patient satisfaction. Lastly, investigators will explore Text4Support implementation outcomes. This will be a multicenter, mixed-methods, longitudinal, prospective, parallel, two-arm, rater-blinded randomized controlled trial. Participants will be randomized into two arms: the intervention arm will receive the usual care, plus daily automated supportive text messages from an online application, and the control arm will receive the usual care, which includes the freely accessible Health Authority approved e-mental health services. It is planned to enrol at least 1500 participants. Quantitative data will be analyzed using repeated measures mixed-effects modelling, effect size analysis, and correlational analysis between measures at each time point on an intention-to-treat basis. Qualitative data analysis will be guided by the six-phase thematic analysis framework. The analysis of the implementation outcomes will be guided by the RE-AIM framework. The results of the study will provide important information with respect to a comprehensive evaluation of outcomes of a supportive daily text message program; comparability of a supportive daily text message program compared with care as usual; and the impact of a supportive daily text message program on clinical outcomes, patient satisfaction and health services utilization.