Reduced symptoms of depression, stress and insomnia were observed in university students after the application of an adapted version of the MBRP, when compared to the control group. However, it did not modify symptoms of anxiety, differing from what was expected. These results add to the literature in respect of the impacts that this type of intervention can have on the mental health of university students.
Also, during protocol, there were statistically significant differences in the symptoms of anxiety, depression and insomnia ever since the first section. Although it has not happened consistently and progressively, in general there was a reduction in these symptoms presented by university students throughout the entire protocol.
A continuous decrease in these symptoms related to mental health in the first three sessions could be seen. In general, these sessions were about the presentation of the concept and relationship of mindfulness to what is experienced in everyday life. A slight increase in symptoms of depression and insomnia was seen after the fourth session, when challenging situations are discussed and how mindfulness can be used to deal with them. In addition to the effect of the session itself, situations outside the context of the practices may also have contributed to the result found, but the changes were slight and the average of both symptoms dropped again the following week, after the fifth session.
After the sixth session, in which thoughts and our reactions to them are worked on, there was an increase in anxiety and insomnia symptoms and depression symptoms remained stable when compared to the previous week. It is possible that, when turning the attention to the thoughts in an attempt to disengage, but still without the consolidated skill, observation brings discomfort and stress, which can affect sleep.
According to the Monitoring and Acceptance Theory (MAT), awareness of experiences, that is, the ability to monitor attention, can explain the improvement presented with regard to the cognitive functioning of individuals who undergo mindfulness protocols, but this same skill can increase affective reactivity (43), which could explain this slight increase. In addition, the theory postulates that acceptance is essential to modify the individual's relationship with the monitored experience, reducing affective reactivity and, therefore, leading to the improvement of negative affectivity and symptoms related to stress (43). Thus, in line with previous studies (44), the present study indicates the possibility that a greater emphasis on acceptance skills, an important emotion regulation mechanism, could maximize the effectiveness of these interventions.
Finally, after the seventh session, when the focus is on self-care, all symptoms showed a visible decrease, which remained until the end of the protocol. One previous study that assessed the weekly change in stress symptoms in patients at a medical center was found, where a statistically significant difference was observed in relation to the baseline only after the fourth session (45). Although the weekly assessment has not been explored much yet, modifications in the length of the protocols have already been tested.
A previous study evaluated the effect of a brief mindfulness intervention performed in just three sessions in an adult audience without major psychological symptoms and observed a decrease in the Depression, Anxiety and Stress Scale (DASS) score and an improvement in life satisfaction (46). Four-session mindfulness interventions have also been previously tested, although there was no consistency between them. While some did not find differences in psychological symptom rating scales after the intervention (47) or compared to the active control group (48), others observed changes similar to the 8-week protocol (49), decreased proinflammatory cytokines related to depression disorder (47), improvements in depression symptoms and of psychological well-being (50) and the reduction of tiredness, anxiety, improvement of visual-spatial processing, working memory and executive functioning (51).
It is already known that the greater the practice of mindfulness at home, that is, at times other than the session itself, the greater the gain obtained (52, 53). However, many students informally claim, throughout the sessions, not finding the time or even remembering to do the practices, especially when the university demands more from them (examination periods, assignments, etc.). The use of cell phone applications to send daily reminders for the personal practice of individuals has already been proposed, having been presented as a viable possibility and well accepted by university students (54, 55). The use of technology combined with the weekly protocol can be a way to further expand the gains obtained by the practice of mindfulness, and future studies are needed to assess how effective the use of this type of tool within the protocol is and whether the weekly gains are also necessarily related to that individual practice.
Thus, the need for further studies to explore the moment when changes happen is highlighted, in order to better understand what are the possible modifications to be made in the protocols. This information could help both cultural or specific adaptations for different populations, as well as changes in the number of sessions of interventions.
Corroborating the initial hypotheses, symptoms of depression presented by the students decreased significantly after the 8-week MBI protocol. This result is in line with the literature, where improvements in these symptoms have already been reported through MBIs in several populations (56, 57) and also in meta-analyses (58, 59). However, mindfulness practices might act upon different cultures in different ways due to their different characteristics and baseline scores (60). Therefore, it is fundamental to keep studying its effects on unexplored or under-explored populations, such as Brazilian university students.
Although none of the participants declared a sleep disorder, the insomnia severity questionnaire pointed to a low quality and quantity of sleep at baseline. This may not have been perceived by students as a problem or been identified as a sleep disorder. Following the intervention, there was an improvement in insomnia symptoms, which might indicate the impact that mindfulness can have on the lives of its practitioners. A lower quality and quantity of sleep have already been shown to be associated with lower academic performance and quality of life, decreased cognitive functions and an increased propensity to develop mental disorders (61–64). Also, it may have consequences that have been singly addressed, such as the symptoms of depression and the increased level of stress. Thus, it is possible that the improved sleep of individuals who underwent the protocol can impact other aspects of their lives. Future studies are needed to investigate this hypothesis.
The protocol used did not specifically focus on stress, but students also reported a decrease in perceived stress after the intervention. Stress is a significant health challenge in the 21st century, with many people developing disorders and having a reduced quality of life due to this instinctive response proving to be maladaptive in some modern contexts. The effect of MBIs on stress has been reported for decades in different populations (65–67). A recent study indicated that stress reduction mediated the positive relationship between mindfulness and well-being in the general population (68), pointing to a central role of this construct in the analysis of the effects of the practice.
However, contrary to our expectations, the students' anxiety symptoms did not improve after the mindfulness protocol when compared to the control group. In fact, there is no consensus in the literature on the effect of mindfulness on anxiety, with some studies pointing to improvements (67, 69) and others, including ours, finding no difference (65, 70). A meta-analysis of the effect of MBIs on anxiety among college students reported a significant improvement, although there is a chance that the result was influenced by publication bias (71). Precisely due to this bias, the importance of reporting the results found in the present study is highlighted. The lack of a significant difference may be the result of several other factors, such as scale sensitivity, since the aforementioned meta-analysis excluded studies that addressed anxiety as a trait because of its greater stability while we chose to use it exactly for this reason; differences in protocols; and the socio-political context of the research, as it was carried out at public universities in a troubled political period with scholarships and grants being cancelled, which may have affected the participants' feelings of insecurity and anxiety.
One important observation made when conducting the research was that students were very interested in taking part in mindfulness practices. Despite this initial interest, there were a high number of dropouts from the groups. There were a number of reasons given for dropping out of the study, but the main unofficial reported reason was the need to prepare for tests, reducing the time they had to take part in other activities. Future researches are necessary in order to better explore the reasons why students dropout.
The study has limitations that should be considered. The use of self-administered questionnaires limits objectivity, making it necessary to use multiple methods to overcome this issue. The high number of dropouts during the protocol, despite being common and within expectations, affects the results of the study and needs to be taken into account. The length of time between the first and last evaluations was short, and a longer follow up might be a better indicator of results. The research sample contained a large disproportion between genders, with 80% being female, and therefore limiting the generalization of the results to men, although previous studies have suggested that the relationship between mindfulness and mental health is similar between genders (72, 73). Moreover, the wait-list control group was not active; as meeting in groups and taking time for yourself (regardless of the use of particular interventions) may impact mental health, it is imperative to evaluate these outcomes in clinical trials using active control groups.
Despite these limitations, the present study makes an important contribution to the literature on interventions to improve the mental health of university students, adding longitudinal data from a population that is still little explored in Brazil. In addition, results from an increasing diversity of populations, settings and cultures can enhance the understanding of the benefits and limits of mindfulness practices. This study also makes it possible to analyse the symptoms throughout the intervention, enabling a better understanding of when and how the changes occur. Finally, this study makes an important contribution to the understanding of how a relatively brief approach (8-weeks protocol) can impact a population that contains a high number of individuals who may suffer with mental health issues.
It is important to emphasize that further studies with a longer follow-up time are required to observe the protocol’s long-term effects. Moreover, it could be of interest to evaluate whether MBIs have an impact on seeking psychological support, and the viability of implementing MBIs’ protocols in universities as a prevention program in order to prevent the development of mental disorders.