Suicide is one of the leading causes of unnatural death in the world. According to the WHO mortality database, number of deaths by suicide in the United States have experienced a 53% increase from 2000 to 2020 (WHO, 2022). In Spain, the annual number of deaths by suicide is almost three times higher than those caused by traffic accidents (Instituto Nacional de Estadística, 2021), and deaths by suicide have experienced an 18% increase in the past two decades (WHO, 2022).

A key aspect to prevent death by suicide is implementing secondary prevention strategies. Secondary prevention consists of acting in the early stages of a disease to prevent its progression; in this case, focusing on people with a history of suicidal ideation or behaviour with the aim of preventing death by suicide (Ghanbari et al., 2015).

Digital medicine can contribute to the management of a large number of mental disorders. Digital medicine has been proposed as one of the most promising therapeutic alternatives to complement traditional mental health care (Bucci et al., 2019). Especially, mobile health (mHealth) is booming thanks to the increasing availability of smartphones worldwide: according to studies, up to 83% of the world's population owns a mobile phone with internet access (ICU, 2020).

This is made possible by the advancement of smartphones and the numerous applications (“apps”) that can be found (Lipschitz et al., 2019). Although mHealth is not intended to replace human interaction, it can be a useful complement, as it has certain advantages over traditional approaches, such as 24-h availability, low cost or the possibility to keep a non-face-to-face follow-up, which was an important advantage during COVID-19 pandemic (Ćosić et al., 2020). MHealth also brings us closer to a participatory model in which patients are involved in their own treatment (Berrouiguet et al., 2018).

MHealth apps should always be supported by scientific evidence. One of the evidence-based treatments that can be easily digitalized is the safety plan. A safety plan is a set of personalized strategies aimed at dealing with a suicidal crisis. The original safety plan was designed by Stanley and Brown (2012) and has been proven in several studies to decrease the risk of suicide (Ferguson et al., 2022). Although the original safety plan was completed in paper format, its digitalization has several advantages. For example, carrying the safety plan on a smartphone can increase its availability when it is needed. Also, changes can be made at any time, increasing the level of customization. Finally, the digital medium allows the addition of elements other than text such as photos of loved ones, videos, songs, phone contacts that can be called directly, or links to maps applications showing the best route to the nearest mental healthcare centre or Emergency Department (Jiménez-Muñoz et al., 2022). Suicide prevention mHealth is a very promising area that has not yet received sufficient attention in the scientific literature. A recent review (Jiménez-Muñoz et al., 2022) found 11 studies exploring the acceptability and feasibility of a smartphone-based safety plan (O'Toole et al., 2019; Kennard et al., 2018, 2015; Muscara et al., 2020; Melvin et al., 2019; Pauwels et al., 2017; Gregory et al., 2017; Jeong et al., 2020; Morgiève et al., 2020; Skovgaard Larsen et al., 2016; O'Grady et al., 2020), with sample sizes ranging from 10 (Jeong et al., 2020) to 129 (O'Toole et al., 2019) and follow-up times ranging from a single session (Kennard et al., 2015) to 6 months (Morgiève et al., 2020). Acceptability and feasibility were generally high. For instance, the BeyondNow intervention was tested in a group of 36 outpatients at high risk of suicide for two months. They obtained high participations rates, and most participants found the app easy to use. All the participants said they would recommend the intervention to their family or friends (Melvin et al., 2019). Similarly, Pauwels et al. (2017) explored the use of the BackUp app for one week in 21 high-risk patients, most of whom said they would continue to use it after the study.

Here we present the findings of the pilot phase of the SmartCrisis 2.0 Randomized Clinical Trial (RCT). This pilot study aimed to explore the feasibility and acceptability of a safety plan contained in the MEmind smartphone app. We hypothesize that the intervention will be feasible and well-accepted, which will be reflected in high participation rates and high scores in the satisfaction surveys.