This project evaluates the effectiveness of three intervention models for the prevention of mental health problems in people who have suffered a recent highly stressful event, through an experimental design, with a control group and random assignment of participants in each group .

The preventive interventions that will be evaluated will be based on three different psychotherapeutic models: brief systemic therapy, cognitive behavioral therapy and mindfulness.

It is expected to observe a significant reduction in post-traumatic and depressive symptoms, and an increase in subjective well-being and post-traumatic growth, compared to the control group. In addition, the moderating effect of psychological processes such as cognitive rumination, emotional self-regulation and coping strategies used in the relationship between the type of intervention and its results will be evaluated.

If the hypotheses are confirmed, this study will allow the prevention of emotional distress associated with a highly stressful event, as well as the promotion of positive results, through empirically supported, low-cost strategies and with results that are capable of demonstrating their effectiveness.

Highly stressful events are alterations in the life history of an individual that require an adaptation effort. Available studies warn that about 82 to 90% of the general population will be exposed to some type of traumatic event at some time in their lives. Chile, for example, is constantly prone to suffer highly stressful events of massive order, due to the high frequency of natural disasters that affect it from time to time: earthquakes, volcanic eruptions, floods, floods, as well as stressors that individually affect such as criminal violence, sexual abuse or threatening diseases. This makes the probability that a person has to be exposed to an event of this type is high, developing from it various consequences.

Although the majority will not develop long-term negative consequences, a significant percentage may develop different mental health problems, such as post-traumatic symptoms, and depression. It is estimated, for example, that 25% of people exposed to the 2010 Chile earthquake in the Bío Bío region developed a post-traumatic stress disorder. Likewise, 13.5% of adolescents exposed to the same earthquake developed high levels of depressive symptomatology.

However, there are also more adaptive responses after living these events, one of them is to grow from the negative experience. This possibility has been called posttraumatic growth [PTG], defined as the perception of positive changes that a person experiences as a result of the process of fighting a trauma. Although this growth is the result of an event that caused people to feel unwell, which explains the high relationship between PTSD and PTG in some cross-sectional studies, in multivariate studies and longitudinal different predictors are observed, and in prospective studies it has been determined that the highest PTG is associated in the long term with a higher level of well-being and a decrease in posttraumatic and depressive symptomatology, as well as a better quality of life.

Prevention and promotion actions are gaining increasing importance in all areas of the health field, including difficulties that occur in emergencies and post-emergencies. It is therefore important to determine the factors that contribute to a higher level of subjective well-being and PTG or a lower level of post-traumatic or depressive symptoms after experiencing a highly stressful event. Research that has been conducted to determine the predictors of these responses has shown their association with perceived severity, rumination, emotional self-regulation, religious coping or other coping strategies, such as the search for social support and the active coping.

In a study carried out by García in 2016-2017 with people facing a highly stressful event such as an accident at work intrusive rumination, brooding, deliberate rumination were determined as early predictors of posttraumatic symptomatology. Subjective severity of the event, negative religious coping and positive reinterpretation (inverse predictor), brooding, negative religious coping and positive religious coping (reverse predictor) were determined as early predictors of depressive symptomatology. Regarding positive responses, deliberate rumination and positive religious coping were determined as predictors of PTG, but only initial well-being was a predictor of subsequent subjective well-being. The strength of this study is that it evaluated the predictors less than a month after the event occurred, and continued its evolution at six months and one year after the accident occurred. Thus arises the possibility, supported by current empirical data, to develop intervention programs that encourage cognitive reassessment, deliberate rumination on the event, positive religious coping, active coping, the search for social support and initial well-being, in addition to reduce expressive suppression, intrusive and negative rumination, and negative religious confrontation.

Prevention is one of the most effective ways to reduce the prevalence of mental health problems, as it aims to reduce risk factors, strengthen protective factors and reduce psychiatric symptoms and disability, as well as early onset of some symptoms of mental disorders; It also improves positive mental health, contributes to better physical health and generates social and economic benefits. The prevention of mental disorders focuses on those determinants that exert a causal influence. Those preventive interventions aimed at strengthening protection factors often overlap with mental health promotion.

Regarding the prevention of post-traumatic symptoms, available studies show interventions aimed at earthquake survivors, serious or terminal diseases, wars and violations, among others.

From a cognitive-behavioral approach, techniques have been proposed aimed at increasing coping resources both instrumental and emotional as well as self-regulation capacity and relaxation training.

In a recent study with a non-clinical population, Mindfulness was used in a four-session intervention, with a decrease in depressive symptomatology, an increase in subjective well-being, as well as a reduction in emotional suppression and rumination and an increase in Cognitive reevaluation as an emotional regulation strategy. The size of the intervention effect was a d-Cohen of 0.65 for depressive symptomatology and 0.64 for psychological well-being, both of average value.

Regarding the brief systemic approach, strategies aimed at strengthening personal resources, resignifying negative experiences, reconnecting with social networks, as well as facilitating emotional expression have been proposed. These strategies were used in women newly diagnosed with breast cancer, through a four-session workshop, obtaining a reduction at the end of the post-traumatic symptomatology intervention, depressive symptomatology and physical discomfort associated with the disease. In this study, the effect size was a d-Cohen of 1.30 for post-traumatic symptomatology and 0.57 for depressive symptomatology, considered high and medium values, respectively.

Given the background presented, it is crucial to develop research that can shed light on the challenges related to the prevention of emotional distress associated with a highly stressful event, such as those that frequently affect the Chilean population, as well as with the promotion of positive results, through empirically backed strategies, of low cost and with results that are capable of demonstrating their effectiveness.

Such interventions will allow early response programs to be implemented in case of massive events, such as natural disasters.

HYPOTHESIS

1. Brief preventive interventions reduce levels of post-traumatic symptoms, and also reduce depressive symptoms and increase levels of post-traumatic growth and subjective well-being in people recently exposed to a highly stressful event.
2. The available preventive models (cognitive-behavioral, mindfulness and brief systemic) have similar and superior results to the control group (waiting list) for the reduction of post-traumatic symptomatology, in addition to the reduction of depressive symptomatology and the increase of growth levels and subjective well-being in people recently exposed to a highly stressful event.
3. The changes produced in the levels of posttraumatic and depressive symptomatology, posttraumatic growth and subjective well-being are maintained six months after the intervention.
4. Changes in the levels of subjective severity of the event, mental rumination, coping strategies and emotional self-regulation mediate the outcome of the interventions.

OVERALL OBJECTIVE Evaluate three brief intervention programs in individual format (cognitive-behavioral, mindfulness and brief systemic) for the prevention of post-traumatic and depressive symptomatology and the promotion of subjective well-being and post-traumatic growth in people who have been exposed to a recent highly stressful event.

SPECIFIC OBJECTIVES

1. Evaluate the effect of brief preventive interventions on posttraumatic symptomatology in people who have been exposed to a recent highly stressful event, at the end of treatment and six months after the intervention.
2. Evaluate the effect of brief preventive interventions on depressive symptomatology, posttraumatic growth and subjective well-being, at the end of treatment and at six months.
3. Evaluate the mediation of changes in cognitive rumination, coping strategies and emotional self-regulation between the intervention and its effect on post-traumatic and depressive symptomatology, post-traumatic growth and subjective well-being.

DESIGN A randomized experimental design of parallel groups will be used, with three randomized intervention modalities and a control group, with repeated measures through pre and post intervention evaluation and follow-up at six months.

PROCESS

The procedure will be divided into three main phases:

A) development of intervention protocols, B) evaluation of the protocols in pilot intervention, C) randomized clinical trial.

A) Development of intervention protocols. For this phase, an exhaustive review of the research literature will be carried out first to examine preventive interventions that have pointed to the decrease in post-traumatic or depressive symptoms or to the promotion of subjective well-being or PTG in the population that has been exposed to a highly stressful or potentially traumatic events. From this review of the literature, interventions will be extracted to be included in individual treatment programs of four sessions for each modality, which will be organized in a treatment manual.

B) Evaluation of the protocols in pilot intervention. Individual intervention pilots will be executed with a small number of participants, 12 in total, 4 for each program, one program for each region in which it will be implemented (Antofagasta, Maule and Bío-Bío). To do this, the following steps will be used: a) selection of therapists, who must demonstrate prior training at the level of courses, graduates or any certified instance in any of the three intervention models to be used, b) training of therapists in the protocol of intervention, both theoretical and expository, as well as through guided exercises, role play and video analysis of their own interventions, c) selection of participants according to the inclusion and exclusion criteria defined, d) pre-intervention evaluation, the defined instrument battery being applied to the participants, e) application of the intervention for four sessions, which will be videotaped, g) application of the post-intervention instrument battery, g ) semi-structured interviews with therapists, to establish adjustments to the program used considering their experience in the application of the same, h) analysis of the videos of the interventions, and i) elaboration of the definitive protocols.

C) Randomized clinical trial Prior to the clinical trial, a dissemination campaign will be carried out in the universities of each city, in order to increase the number of people susceptible to receiving care. For the intervention itself, the CONSORT protocol will be followed for randomized clinical trials. The final intervention protocols will be executed for 160 participants, 40 for each intervention program and 40 for the control group on the waiting list. To do this, the following steps will be used: a) inclusion of therapists who participated in the pilot trial, and training of new therapists, who meet the requirements outlined in the previous section, in the intervention protocols, b) evaluation of depressive symptomatology and post-traumatic, because given the preventive nature of the interventions, people with high levels in these cadres will not participate in the study and will be referred to free psychological care in the sponsoring universities, c) randomization to the 3 types of intervention and control group, using ad-hoc software, d) pre-intervention evaluation, e) application of the intervention, 25% of which will be videotaped, in order to ensure the fidelity of the intervention and supervise the Therapists, f) post-intervention evaluation, g) follow-up (at six months). In the case of the control group on the waiting list, they will start the intervention four weeks after their first evaluation, in order to have a comparison group without intervention in the second measurement. However, when intervened after the fourth week (once again randomizing the type of intervention), there will be no control group for follow-up. This for ethical reasons, because you cannot leave someone who requires it without the support that the rest of the participants receive. In addition, those who show high rates of discomfort at follow-up will also be referred to free psychotherapy in the sponsoring universities.

Inclusion Criteria:

• Inclusion criteria will be to be of legal age and to have lived the highly stressful experience in the last three months (a check-list of events will be available).

Exclusion Criteria:

• Those who have already been previously given psychological care will be excluded due to the consequences generated by the same event and who, due to their health condition, are prevented from receiving individual care in the first three months after the event.