The role of gratitude and optimism interventions in reducing suicide risk and enhancing wellbeing among university students

Abstract

Background

Suicide risk among university students continues to rise globally, underscoring the need for preventive strategies that cultivate resilience. Gratitude and optimism, core constructs in positive psychology, may strengthen coping and reduce distress. However, few studies have examined their direct impact on suicide-related outcomes in this population. To evaluate the effectiveness of a five-week group program integrating gratitude and optimism exercises in improving wellbeing and reducing suicide-risk correlates.

Method

Six hundred sixty-one Spanish university students (286 men, 375 women; Mage = 21.04) were assigned to intervention (n = 418) or control (n = 243) groups based on course enrollment availability. The intervention included weekly activities based on gratitude journaling, best possible self-visualization, and prosocial exercises. Measures of gratitude (GR-5), optimism (LOT-R), life satisfaction (SWLS), depression (BDI-II), suicidal ideation, and suicidal behavior were collected pre- and post-intervention. Mixed ANOVAs (Group × Time) assessed effects.

Results

Significant Group × Time interactions emerged for gratitude, optimism, life satisfaction, and depression. Modest but significant effects were found for suicidal ideation, and suicidal behavior. The intervention group showed substantial increases in gratitude, optimism, and life satisfaction, accompanied by notable reductions in depressive symptoms and self-harm indicators. Increases in gratitude and optimism in the intervention group were associated with increased life satisfaction and a decrease in depression, suicidal ideation and behaviour, significantly compared to the control group.

Conclusions

Short-term gratitude + optimism training effectively enhances wellbeing and reduces suicide-risk correlates among university students. Findings support the integration of scalable positive-psychology interventions within campus mental-health programs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40359-026-04274-2.

Background and importance

Suicide is one of the most pressing public health challenges worldwide, claiming approximately 703,000 lives annually, according to the World Health Organization [1]. Among vulnerable populations, university students are particularly at risk due to the convergence of developmental, social, and academic pressures during their transition into adulthood [2–4]. In some regions, suicide rates among young adults rank as the second leading cause of death, underscoring the urgency for effective prevention strategies within this population [5]. Research indicates that mental health crises, including depression, anxiety, and suicidal ideation, are increasingly prevalent among university students [6]. These mental health challenges are increasingly prevalent, demanding effective, evidence-based interventions within university settings [7].

University life presents a unique combination of stressors that can exacerbate emotional vulnerabilities [2, 8, 9]. Academic pressure, for instance, is one of the most significant contributors to stress, with students facing high expectations to perform well in exams, meet deadlines, and secure future employment opportunities. Social isolation often compounds this stress, particularly for students who move away from their families and established support networks. Additionally, financial strain, exacerbated by rising tuition fees and living costs, creates further challenges, leaving students feeling overwhelmed and helpless. These stressors might affect students’ mental health and influence their risk of suicide [2, 10]. Therefore, addressing this issue requires targeted, evidence-based interventions designed to alleviate stress, enhance coping mechanisms, and promote resilience among university students.

Although many stressors (e.g., academic demands, social transitions, and financial strain) are frequently reported across university contexts, their salience and meaning are shaped by cultural and institutional environments. In Spain, the university experience often occurs within comparatively strong family ties and public higher-education structures, which may influence help-seeking norms, perceived social support, and the way students interpret academic pressure. A study developed in the university of Malaga (Spain) concluded that psychological distress is a risk factor for suicidal behavior, while resilience and family and social support are linked to a lower risk of suicide [11]. Accordingly, we frame the present intervention as embedded in a Spanish university setting and interpret generalizability cautiously.

Theoretical framework

The emergence of positive psychology has introduced new perspectives emphasizing psychological strengths and well-being rather than pathology [12]. Within this framework, gratitude and optimism have gained substantial attention as protective factors that promote emotional resilience, enhance coping, and buffer against mental distress [12, 13]. Gratitude, defined as the recognition and appreciation of positive aspects of life, has been linked to lower depressive symptoms, increased life satisfaction, and stronger social connectedness [14]. Optimism, characterized by generalized positive expectancies for the future, contributes to adaptive coping and lower psychological distress [14, 15].

These constructs align with Martin Seligman’s Positive Psychology model, which emphasizes building strengths, fostering positive emotions, and cultivating meaningful connections as pathways to a flourishing life [12]. Gratitude, for instance, has been shown to enhance emotional regulation and foster social support networks, reducing feelings of loneliness and hopelessness, two key predictors of suicide risk [16]. Similarly, optimism promotes adaptive coping strategies, such as problem-solving and cognitive reframing, which can mitigate the effects of stress and negative life events [17]. Fredrickson’s Broaden-and-Build theory [18] provides a conceptual basis for these constructs, positing that positive emotions expand cognitive flexibility and build enduring psychological resources. Similarly, Lazarus and Folkman’s [19] Stress and Coping model emphasizes cognitive appraisal and coping processes, suggesting that optimistic and grateful orientations enable more constructive responses to stress. Integrating these theories, interventions targeting gratitude and optimism may serve as low-cost, preventive tools for reducing suicide risk and promoting student well-being. Both constructs have been linked to improvements in life satisfaction, reduced depressive symptoms, and increased psychological resilience, making them promising tools for suicide prevention and mental health promotion among university students [20]. Recent research conducted by Sánchez-Álvarez and colleagues has provided empirical evidence on the beneficial effects of gratitude and optimism in promoting well-being and emotional adjustment among Spanish university students [21]. These findings support the view that fostering positive psychological resources can enhance resilience and reduce vulnerability to depressive and suicidal symptoms, which served as a conceptual foundation for the current intervention [22].

Gratitude and mental health

Gratitude, defined as a deep appreciation for the positive aspects of life and interpersonal relationships, has been consistently linked to improved mental health outcomes [16]. Several studies demonstrate that cultivating gratitude can significantly reduce depression, anxiety, and suicidal ideation. For instance, a study by Emmons and McCullough [23] found that participants who engaged in gratitude journaling for three weeks reported higher levels of happiness and reduced depressive symptoms compared to control groups. Similarly, Lambert et al. [24] demonstrated that expressing gratitude enhanced relationship satisfaction and reduced feelings of loneliness, both key predictors of suicidal ideation.

Mechanisms underlying gratitude’s impact on mental health include enhanced emotional regulation and the fostering of social bonds [24, 25, ]. Emotional regulation refers to the ability to manage and respond to negative emotions effectively, a skill often compromised in individuals with depression or anxiety [26]. Gratitude exercises promote positive reframing of stressful events, enabling individuals to focus on what they have rather than what they lack. Moreover, gratitude strengthens social connections by encouraging acts of kindness and reciprocity, thereby reducing feelings of isolation [27]. These mechanisms suggest that gratitude not only alleviates psychological distress but also builds protective factors against future mental health challenges.

Emerging evidence also points to the potential of gratitude interventions in suicide prevention. Kerr et al. [28] found that gratitude exercises significantly reduced hopelessness, a major risk factor for suicide, among individuals experiencing high levels of stress. By shifting attention from life’s difficulties to its blessings, gratitude interventions can foster a sense of meaning and purpose, critical elements in combating suicidal ideation.

Optimism and wellbeing

Optimism, defined as the tendency to expect positive outcomes in the future, has long been recognized as a protective factor against mental health challenges [17]. Research shows that optimistic individuals are less likely to experience depressive symptoms, anxiety, and suicidal ideation [21]. For example, Carver et al. [13] demonstrated that optimism predicts lower levels of emotional distress following adverse life events, highlighting its role as a resilience-enhancing trait. One of the keyways optimisms promotes wellbeing is through its impact on coping strategies. Optimistic individuals are more likely to engage in problem-focused coping, which involves actively addressing stressors, rather than avoidance or rumination [29]. This proactive approach helps mitigate the effects of stress and reduces the likelihood of mental health deterioration. Additionally, optimism has been linked to improved physical health, including better cardiovascular outcomes and immune system functioning, which indirectly support psychological resilience [15].

In the context of suicide prevention, optimism plays a crucial role in fostering hope and future orientation. Snyder’s [30] theory of hope, which overlaps with optimism, posits that individuals with a positive outlook are more likely to set and pursue meaningful goals. This sense of purpose can act as a buffer against despair and suicidal ideation. Studies by Hirsch et al. [31] further support this, showing that optimism interventions, such as guided visualization exercises, significantly reduce suicide risk among individuals with a history of depression.

Combined interventions

While gratitude and optimism independently contribute to mental health improvements, combining these interventions may produce complementary effects. Integrated programs that incorporate gratitude journaling and optimism exercises have shown promising results in reducing stress and enhancing psychological wellbeing. For instance, Seligman et al. [32] conducted a randomized controlled trial in which participants engaged in both gratitude and optimism exercises over six weeks. The intervention led to significant increases in happiness and reductions in depressive symptoms, effects that persisted for six months post-intervention.

One effective combined approach is gratitude journaling paired with future-oriented goal setting. Gratitude journaling involves listing daily or weekly positive experiences, which fosters an appreciation for the present. When paired with exercises that encourage envisioning the best possible future, such as imagining one’s ideal career or personal achievements, the intervention can cultivate both present-focused contentment and future-oriented hope [33].

Digital platforms have also emerged as a medium for delivering combined gratitude and optimism interventions. For example, online programs like Happify and Thrive have integrated exercises such as writing gratitude letters and guided optimism meditations into their modules [34]. These platforms allow for scalability, making interventions accessible to a broader audience. Preliminary studies on such programs indicate significant reductions in stress and improvements in life satisfaction among university students [35].

Moreover, group-based interventions have shown potential in fostering peer support and collective resilience. For instance, group workshops combining gratitude exercises with optimism training have been implemented in university settings with notable success. These workshops often include activities such as sharing gratitude stories, setting collective goals, and practicing positive visualization. A study by Rashid and Seligman [36] found that such group-based interventions not only reduced depressive symptoms but also enhanced social cohesion, a critical protective factor against suicide risk.

Despite their promise, combined interventions face challenges, such as variability in individual engagement and cultural differences in how gratitude and optimism are perceived. For instance, in collectivist cultures, gratitude exercises that focus on interpersonal relationships may be more effective than those emphasizing individual achievements [37]. Understanding these nuances is essential for tailoring interventions to diverse populations.

Existing research highlights the significant potential of gratitude and optimism interventions in reducing suicide risk and promoting wellbeing among university students. Gratitude enhances emotional regulation and fosters social bonds [24, 25], while optimism promotes adaptive coping strategies and resilience [13]. Combined interventions that integrate these constructs offer a holistic approach to mental health, addressing both present-focused contentment and future-oriented hope. However, further research is needed to optimize these interventions and ensure their accessibility and effectiveness across diverse cultural and demographic contexts. The integration of these interventions into university mental health programs represents a promising step toward addressing the growing mental health crisis in this vulnerable population.

Purpose of the present study

Recent research supports the efficacy of brief gratitude and optimism interventions in enhancing well-being across diverse populations. For instance, Kerr et al. [28] found that gratitude exercises reduced hopelessness and depressive symptoms, while Rashid and Seligman [36] demonstrated that positive psychotherapy integrating gratitude and optimism significantly improved happiness and life satisfaction. Among university students, combined interventions involving gratitude journaling and ‘best possible self’ exercises have shown improvements in resilience, motivation, and psychological health [34, 37].

However, despite promising results, few studies have directly examined their role in reducing suicidal ideation and behavior. The main objective of this study was to examine whether participation in a five-week gratitude and optimism intervention leads to improvements in psychological well-being and reductions in suicide-related variables among university students. Specifically, we hypothesized that, compared to a non-intervention control group: Participants in the intervention group would show increased levels of gratitude, optimism, and life satisfaction after the intervention. Participants would show decreased depressive symptoms, suicidal ideation, and suicidal behaviours. We also expected that greater adherence to the activities would be associated with stronger improvements.

Method

Participants

Participants were 661 undergraduate students from the University of Málaga, Spain (286 men, 375 women; M_age = 21.04, SD = 2.87). Of these, 418 participated in the intervention group and 243 in the control group. Inclusion criteria included being enrolled in undergraduate studies and providing informed consent. The study received ethical approval from the University of Málaga Institutional Review Board (161-2023-H) and followed the Declaration of Helsinki (2013), and participation was voluntary and anonymous.

The study reported an attrition rate of 3.9%. Nevertheless, no significant differences were observed between participants who discontinued and those who completed the study regarding pre- and post-assessment scores, or in attendance to the intervention sessions.

Design and procedure

A quasi-experimental pre–post design with two groups (intervention vs. control) and two time points (baseline and post-intervention) was used. The experimental group participated in a structured five-session intervention (90 min each) focused on cultivating gratitude and optimism through experiential and reflective activities. The intervention was adapted from the Positive Psychotherapy (PPT) framework developed by Rashid and Seligman [36]. While the original PPT program comprises 15 sessions covering a wide range of positive psychology constructs, the present study condensed the structure into five 90-minute sessions focusing specifically on gratitude and optimism. This adaptation prioritized core experiential and reflective exercises, such as gratitude journaling, gratitude letters, best possible self-visualization, and positive reframing, to enhance emotional awareness, cognitive flexibility, and future-oriented thinking. The streamlined format was designed to maintain the theoretical integrity of PPT while ensuring feasibility within a university context. Control participants received no intervention during this period. Data collection was performed online before and immediately after the intervention using secure survey tools. All participants received course credit for completing both assessments.

About Intervention format and delivery, sessions were delivered in small groups during the academic term at the University of Malaga. Each session lasted approximately 90 min and was facilitated by trained psychologists/research staff (facilitator-to-student ratio approximately 1:5). Group sizes ranged from 5 to 8 students. Sessions were scheduled weekly (one session per week) and were conducted outside class time. The original Positive Psychotherapy (PPT) protocol comprises 15 sessions covering multiple positive psychology strengths. For feasibility in a university context, we retained the PPT components most directly aligned with gratitude and optimism and omitted modules focused on other strengths (e.g., forgiveness, spirituality, savoring, and character strengths identification) that were not central to the present research aims. The retained exercises were: (a) gratitude journaling (weekly ‘three good things’ + reflection prompts), (b) gratitude letter (writing and, when feasible, delivering the letter), (c) prosocial ‘acts of kindness’ planning and reflection, (d) best possible self visualization and goal-setting, and (e) cognitive reappraisal/positive reframing practice applied to academic and interpersonal stressors. Although several activities were completed individually (e.g., writing tasks), each session included structured peer sharing (e.g., guided reflection in dyads or small subgroups) and brief plenary discussion moderated by the facilitator. This format was designed to leverage social connectedness and normalization processes commonly observed in group-based positive psychology programs.

Regarding because suicide-related variables were assessed, a safety protocol was implemented. Prior to participation, students were informed that the study was not a clinical service and that they could request support at any time. Participants who endorsed elevated risk indicators on the suicide measures (e.g., reporting recent suicidal intent/plan) were automatically shown an on-screen message with crisis resources and the university mental health service contact information, and (when permission was granted) were contacted by a licensed clinician associated with the project within. The study procedures were approved by the University of Malaga IRB (161-2023-H).

Given the non-random assignment based on course availability, we examined baseline equivalence between groups on all study variables (and key demographics). Groups did not differ significantly in the baseline of gratitude, optimism, life satisfaction, depression, suicidal ideation, or suicidal behavior supporting comparability. Where small baseline differences were observed, sensitivity analyses using ANCOVA (post scores adjusted for baseline) yielded the same pattern of conclusions.

Measures

Gratitude was assessed using the Gratitude Questionnaire-6 (GQ-6) [38]. The GQ measure of grateful disposition through 6 items, whose total score reflects the ability to forgive that a person shows both towards himself and towards other people, as well as towards situations that are beyond his control. Similarly, this scale offers differentiated scores for the different subscales of self-forgiveness, forgiveness towards other people and forgiveness of uncontrollable situations. The instrument has a satisfactory reliability index (α_pre = 0.77, α_post = 0.70). We used the Spanish translation of the GQ [39].

Optimism was measured with the Life Orientation Test-Revised (LOT-R) [40]. The LOT-R is a ten-item self-report instrument designed to assess dispositional optimism, defined as the generalized tendency to expect positive rather than negative outcomes in life. Items are rated on a 5-point Likert scale ranging from 0 (“strongly disagree”) to 4 (“strongly agree”), with higher scores indicating greater optimism. The scale comprises six scored items, three positively and three negatively worded statements, and four fillers. The LOT-R has shown strong psychometric properties, including good internal consistency and test–retest reliability across diverse populations. In the present study, internal consistency was satisfactory (α_pre = 0.75, α_post = 0.76), supporting its reliability for assessing optimism in university students. We used a Spanish version of LOT-R [41].

Satisfaction with Life Scale (SWLS) [42]. The SWLS is a five-item self-report measure that evaluates individuals’ global cognitive judgments of their overall satisfaction with life. Participants rate each item on a 5-point Likert scale ranging from 1 (“strongly disagree”) to 5 (“strongly agree”), with higher total scores indicating greater life satisfaction. The scale is widely used in research on well-being and has demonstrated excellent psychometric properties across cultures, including strong convergent validity with measures of positive affect and happiness. In the present study, the SWLS showed high internal reliability, with Cronbach’s α = 0.89 at baseline and α = 0.90 at post-intervention, confirming its stability and consistency for assessing subjective well-being among university students. The Spanish version of SWLS was used [43].

Depression was measured with the Beck Depression Inventory-II (BDI-II) [44]. It is composed of 21 items that evaluate symptoms such as crying, loss of pleasure, sadness, feelings of guilt and failure, pessimism, and thoughts or desires of suicide, among other symptoms. Each of the 21 items is answered on a 4-point scale, ranging from 0 to 3. The scales state that a score between 0 and 9 indicates an absence of depression, a score of 10 to 18 mild depression, a score between 19- and 29-points moderate depression, and a score of 30 to 63, major depression. This measuring instrument has an excellent internal consistency (α_pre = 0.87, α_post = 0.91). For this study, we used a Spanish version of BDI-II [45].

Suicidal ideation was measured with the Frequency of Suicidal Ideation Inventory (FSII) [46]. The FSII is a 5-item self-report measure designed to assess the frequency and intensity of suicidal thoughts experienced over the past 12 months. Respondents rate each item on a 5-point Likert scale ranging from 1 (“never”) to 5 (“almost every day”), with total scores ranging from 5 to 25; higher scores indicate greater frequency of suicidal ideation. The instrument captures both the persistence and recurrence of suicidal thinking, providing a reliable indicator of suicide risk severity. Previous research has demonstrated the FSII’s strong internal consistency and construct validity across clinical and non-clinical samples. In the present study, internal reliability was excellent (α_pre = 0.91, α_post = 0.93), confirming the robustness of the measure for use in university populations. We used a Spanish version of FSII [47].

Suicidal behaviour was measured with the Suicidal Behaviours Questionnaire-Revised (SBQ-R) [48]. The SBQ-R is a brief, four-item self-report measure designed to assess key dimensions of suicidal ideation and behavior, including lifetime suicide attempts, the frequency of suicidal thoughts, the threat of suicidal behavior, and the likelihood of future suicidal acts. Each item uses a different response format, with higher total scores indicating greater risk for suicidal behavior. The SBQ-R has demonstrated solid psychometric properties across adolescent and adult populations, showing good convergent validity with other measures of suicidality and psychological distress. In the present study, internal consistency was acceptable, with Cronbach’s α = 0.71 at baseline and α = 0.77 at post-intervention, supporting its reliability as a screening tool for suicidal behavior among university students. In this study, the Spanish version of SBQ-R was used [49].

Data analysis

All analyses were conducted in IBM SPSS Statistics (v29). To address familywise Type I error inflation and to provide an omnibus test of intervention effects, we first conducted a 2 (Group: intervention vs. control) × 2 (Time: pre vs. post) mixed-model MANOVA including all six outcomes (gratitude, optimism, life satisfaction, depression, suicidal ideation, and suicidal behavior). Significant multivariate effects were followed by the corresponding univariate mixed ANOVAs for each outcome. For the set of six univariate tests, p-values were additionally evaluated using a Holm-Bonferroni correction, although conclusions were unchanged.

Baseline equivalence between groups was examined using independent-samples t-tests (continuous variables) and χ² tests (categorical variables). Because assignment was quasi-experimental, we also conducted sensitivity analyses using ANCOVA (post-test outcome as dependent variable, baseline score as covariate) to verify robustness. Effect sizes are reported as partial eta squared (η²p) for ANOVA/MANOVA and standardized beta coefficients for regressions. To examine whether improvements in positive resources uniquely predicted reductions in risk indicators, we computed change scores (Δ = post − pre) and ran three multiple regression models with ΔDepression, ΔSuicidal Ideation, and ΔSuicidal Behavior as outcomes. Predictors were ΔOptimism, ΔGratitude, and ΔLife Satisfaction entered using a forward selection approach (entry p < 0.05). In parallel, we retained the preregistered/descriptive correlational analyses of Δ scores within each group. Differences between independent correlations were tested using Fisher’s r-to-z transformation; all pairwise comparisons (15 per group) are reported in Table 3.

Table 3.

Comparisons between pearson correlations among change scores by group

Variables comparisons	Intervention group	Control group	Z diff	p
ΔOptimism - ΔGratitude	0.46	0.31	1.71	0.087
ΔOptimism - ΔDepression	–0.48	–0.18	–3.48	< 0.001
ΔOptimism – ΔSuicidal Ideation	–0.28	–0.25	0.36	0.719
ΔOptimism – ΔSuicidal Behavior	–0.17	–0.10	0.78	0.435
ΔOptimism – ΔLife Satisfaction	0.45	0.34	1.33	0.183
ΔGratitude – ΔDepression	–0.45	–0.10	–4.11	< 0.001
ΔGratitude – ΔSuicidal Ideation	–0.27	–0.13	–1.67	0.095
ΔGratitude – ΔSuicidal Behavior	–0.16	–0.04	–1.40	0.162
ΔGratitude – ΔLife Satisfaction	0.52	0.31	2.59	0.010
ΔDepression – ΔSuicidal Ideation	0.41	0.31	1.20	0.230
ΔDepression – ΔSuicidal Behavior	0.39	0.23	1.91	0.056
ΔDepression – ΔLife Satisfaction	–0.67	–0.30	–4.88	< 0.001
ΔSuicidal Ideation – ΔSuicidal Behavior	0.44	0.49	–0.56	0.575
ΔSuicidal Ideation – ΔLife Satisfaction	–0.31	–0.29	0.23	0.818
ΔSuicidal Behavior – ΔLife Satisfaction	–0.40	–0.27	–1.55	0.121

Results

Inferential analyses

The analyses examined the effects of a five-week gratitude and optimism intervention on six psychological outcomes: gratitude, optimism, life satisfaction, depression, suicidal ideation, and suicidal behavior. First, a 2 × 2 mixed multivariate analysis of variance (MANOVA) with repeated measures was conducted, with Time (pre, post) as the within-subject factor and Group (intervention, control) as the between-subject factor. Multiple outcome variables were analyzed simultaneously. Multivariate effects were evaluated using Pillai’s Trace due to its robustness to assumption violations. The multivariate Time × Group interaction was statistically significant, Pillai’s Trace = 0.191, F(6, 523) = 20.56, p < 0.001, η²p = 0.191. Follow-up univariate analyses revealed significant Time × Group interactions for all outcome variables. All effects remained statistically significant after Holm–Bonferroni correction for multiple comparisons. Next, univariate analyses were performed for each variable. Descriptive statistics and mixed ANOVAs (Group × Time) are presented below. Results revealed significant improvements in positive psychological constructs and reductions in depression and suicide-related measures among intervention participants. Table 1 presents the pre- and post-intervention means and standard deviations. Significant Group × Time interactions were observed across all major variables, indicating that participants in the intervention experienced substantial improvements in gratitude, optimism, and life satisfaction, accompanied by reductions in depressive symptoms, suicidal ideation, and suicidal behavior.

Table 1.

Pre- and post-intervention means and standard deviations for all outcome variables

Variable	Group	Pre M (SD)	Post M (SD)	t	Test-retest r	F	η²ₚ
Gratitude	Control	5.45 (0.98)	5.33 (0.98)	2.24*	0.66	46.99***	0.072
	Intervention	5.36 (1.09)	5.80 (1.09)	-8.25***	0.43
Optimism	Control	13.38 (4.25)	14.12 (4.25)	-3.31**	0.70	83.03***	0.120
	Intervention	13.27 (4.37)	17.08 (4.37)	-17.30**	0.45
Life Satisfaction	Control	23.44 (7.07)	25.20 (7.07)	-4.94***	0.70	37.24***	0.058
	Intervention	23.51 (6.99)	28.27 (6.99)	-15.45***	0.54
Depression	Control	10.43 (9.21)	9.04 (9.21)	3.31**	0.80	64.50***	0.108
	Intervention	12.24 (9.78)	5.10 (9.78)	8.07***	0.49
Suicidal Ideation	Control	7.61 (3.71)	7.33 (3.71)	1.52	0.71	4.20*	0.007
	Intervention	7.99 (4.12)	7.17 (4.12)	4.94***	0.67
Suicidal Behavior	Control	3.14 (3.16)	2.78 (3.16)	2.27*	0.75	9.94**	0.017
	Intervention	3.49 (3.62)	2.49 (3.62)	8.18***	0.77

p < 0.05*, p < 0.01**, p < 0.001***

Mixed-design ANOVAs revealed significant Group × Time interactions across all major outcomes. Gratitude increased significantly in the intervention group, F(1,609) = 46.99, p < 0.001, η²ₚ = 0.072. Optimism showed a robust improvement, F(1,608) = 83.03, p < 0.001, η²ₚ = 0.120. Life satisfaction rose markedly, F(1,609) = 37.24, p < 0.001, η²ₚ = 0.058. Depressive symptoms decreased significantly, F(1,530) = 64.50, p < 0.001, η²ₚ = 0.108. Suicidal ideation exhibited a small but significant decline, F(1,609) = 4.20, p = 0.041, η²ₚ = 0.007, and suicidal behavior decreased notably, F(1,570) = 9.94, p = 0.002, η²ₚ = 0.017. All effects were in the expected direction, favoring the intervention. Effect sizes ranged from small (suicidal ideation) to large (optimism, depression). These results indicate that the gratitude and optimism intervention yielded consistent and meaningful psychological benefits. These findings suggest that the combined gratitude and optimism intervention effectively enhanced psychological well-being and mitigated suicide-risk correlates among university students.

Correlational analyses between change scores

To explore the associations among improvements across psychological outcomes, Pearson correlations were computed separately for the intervention and control groups using change scores (post-intervention minus pre-intervention values), see Table 2. Correlations in the intervention group were generally stronger, especially between ΔOptimism, ΔGratitude, and ΔLife Satisfaction, as well as their inverse associations with ΔDepression and suicide-related outcomes, supporting the coherence of positive emotional growth and reduced risk indicators following the intervention. In the intervention group, increases in gratitude and optimism were strongly associated (r = 0.46, p < 0.001), and both were inversely related to changes in depression (r = –0.45 to –0.48, p < 0.001) and suicide-related outcomes (r = –0.27 to –0.31, p < 0.001). Moreover, improvements in life satisfaction correlated positively with gains in gratitude (r = 0.52, p < 0.001) and optimism (r = 0.45, p < 0.001), and negatively with changes in depression (r = –0.67, p < 0.001), suicidal ideation (r = –0.31, p < .001), and suicidal behavior (r = –0.40, p < 0.001). These findings indicate that participants who experienced the greatest improvements in gratitude and optimism also reported the largest decreases in depressive and suicidal symptoms. In contrast, in the control group, correlations among change scores were weaker and less consistent (e.g., r values typically below 0.30). This pattern suggests that the interrelations among positive and negative psychological changes were more coherent and systematic in the intervention group.

Table 2.

Pearson correlations among change scores by group (Post – pre)

Variable	1	2	3	4	5	6
1. ΔOptimism	—	0.46***	–0.48***	–0.28***	–0.17**	0.45***
2. ΔGratitude	0.31***	—	–0.45***	–0.27***	–0.16**	0.52***
3. ΔDepression	–0.18*	–0.10	—	0.41***	0.39***	–0.67***
4. ΔSuicidal Ideation	–0.25***	–0.13	0.31***	—	0.44***	–0.31***
5. ΔSuicidal Behavior	–0.10	–0.04	0.23**	0.49***	—	–0.40***
6. ΔLife Satisfaction	0.34***	0.31***	–0.30***	–0.29***	–0.27***	—

p < 0.05*, p < 0.01**, p < 0.001***

To evaluate whether the strength of these associations differed significantly between groups, Fisher’s r-to-z transformation [50] was used. This method converts Pearson correlation coefficients to z values, allowing direct statistical comparison between independent samples. Comparisons using Fisher’s r-to-z transformation indicated that correlations between ΔOptimism–ΔDepression, ΔGratitude–ΔDepression, and ΔGratitude–ΔLife Satisfaction were significantly stronger in the intervention group than in the control group, supporting the notion that positive constructs became more tightly coupled as a result of the intervention, see Table 3. This indicates that the psychological constructs became more interrelated following participation in the intervention, consistent with the notion that positive emotion-based practices foster integrated growth across affective and cognitive domains.

Multiple regression analyses predicting changes in risk indicators

To examine whether improvements in positive resources uniquely predicted reductions in risk indicators, we computed change scores (Δ = post − pre) for all study variables and conducted three multiple regression analyses with ΔDepression, ΔSuicidal Ideation, and ΔSuicidal Behavior as dependent variables. In each model, ΔOptimism, ΔGratitude, and ΔLife Satisfaction were entered as candidate predictors using a forward selection procedure. See Table 4. First, the overall regression model was statistically significant and explained a substantial proportion of variance in changes in depressive symptoms, R² = 0.440. All three positive resources emerged as significant unique predictors of changes in depressive symptoms. Increases in life satisfaction showed the strongest association with reductions in depressive symptoms (β = −0.453, p < 0.001), followed by increases in optimism (β = −0.235, p < 0.001). Improvements in gratitude also independently predicted decreases in depressive symptoms, although with a smaller effect size (β = −0.106, p = 0.008). Overall, greater improvements in optimism, gratitude, and life satisfaction were uniquely associated with larger reductions in depressive symptoms over time, with life satisfaction accounting for the largest share of unique variance. Second, the overall regression model was statistically significant, accounting for a modest but meaningful proportion of variance in changes in suicidal ideation, R² = 0.126. In the final model, increases in life satisfaction (β = −0.208, p < 0.001) and optimism (β = −0.153, p < 0.001) independently predicted reductions in suicidal ideation. Changes in gratitude did not contribute unique explanatory power once the other positive resources were taken into account (β = −0.070, p = 0.127). Thus, greater improvements in optimism and life satisfaction were uniquely associated with larger decreases in suicidal ideation over time, whereas changes in gratitude were not independently related to changes in suicidal ideation. Finally, the overall regression model was statistically significant, explaining a modest but meaningful proportion of variance in changes in suicidal behavior, R² = 0.145. In the final model, increases in life satisfaction emerged as the only significant unique predictor of reductions in suicidal behavior (β = −0.395, p < 0.001). Changes in optimism (β = −0.039, p = 0.404) and gratitude (β = 0.077, p = 0.104) did not contribute unique explanatory power once life satisfaction was taken into account. These results indicate that improvements in life satisfaction are uniquely associated with decreases in suicidal behavior over time, whereas changes in optimism and gratitude do not independently predict behavioral risk when shared variance among positive resources is controlled.

Table 4.

Multiple linear regression models predicting changes in risk indicators

Outcome	Predictor	R²	β	t	p
ΔDepression	ΔOptimism	0.440	− 0.235***	-6.03	< 0.001
	ΔGratitude		− 0.106**	-2.68	0.008
	ΔLife Satisfaction		− 0.453***	-11.54	< 0.001
ΔSuicidal Ideation	ΔOptimism	0.126	− 0.153***	-3.37	< 0.001
	ΔGratitude		− 0.070	-1.53	0.127
	ΔLife Satisfaction		− 0.208***	-4.54	< 0.001
ΔSuicidal Behavior	ΔOptimism	0.145	− 0.039	-0.84	0.404
	ΔGratitude		0.077	1.63	0.104
	ΔLife Satisfaction		− 0.395***	-8.44	< 0.001

Change scores (Δ = post – pre) were used for all variables. Standardized regression coefficients (β) are reported

* p < 0.05, ** p < 0.01, *** p < 0.001

Across the three regression models, positive psychological resources showed differential predictive patterns depending on the risk indicator examined. Reductions in depressive symptoms were uniquely predicted by increases in life satisfaction, optimism, and gratitude, whereas reductions in suicidal ideation were predicted by increases in life satisfaction and optimism, but not gratitude. In contrast, reductions in suicidal behavior were uniquely predicted by increases in life satisfaction, with neither optimism nor gratitude contributing independent explanatory power. This pattern suggests increasing specificity of positive resources as outcomes move from affective symptoms to more proximal behavioral risk indicators.

Discussion

The present study provides evidence consistent with the effectiveness of a structured five-week gratitude and optimism intervention in enhancing psychological well-being among university students. Across outcomes, the intervention was associated with increases in gratitude, optimism, and life satisfaction, alongside reductions in depressive symptoms. Effects for suicide-related outcomes were modest but statistically significant, warranting cautious interpretation given the quasi-experimental design and the absence of long-term follow-up.

Interpretation of findings

The observed Group × Time patterns suggest that cultivating gratitude and optimism may be accompanied by improvements in affective and cognitive functioning that coincide with reduced distress. However, because proposed mechanisms (e.g., emotional regulation, cognitive reappraisal, social connectedness) were not directly measured, mechanistic interpretations remain tentative. Change-score associations and the added regression models offer descriptive evidence regarding how improvements in positive resources relate to reductions in depression and suicide-risk correlates, but they do not establish causal pathways.

These findings are consistent with previous empirical work demonstrating that gratitude and optimism interventions reduce symptoms of depression and hopelessness [13, 22, 27], while promoting positive affect and life satisfaction [35, 37]. The present study extends this literature by confirming that such interventions can also yield measurable effects on suicide-related outcomes, which remain understudied within university populations. The dual focus on gratitude and optimism appears to create a reinforcing cycle: gratitude enhances awareness of supportive social networks and present-moment appreciation, whereas optimism strengthens future orientation and goal-directed behavior. Together, these constructs appear to promote both immediate well-being and long-term psychological resilience.

Theoretical and practical implications

From a theoretical standpoint, the results provide further validation for Fredrickson’s [18] proposition that positive emotions have broadening effects that accumulate into lasting psychological resources. Gratitude practices, such as journaling and letter writing, may have cultivated feelings of connectedness and social reciprocity, protective factors against isolation and hopelessness [23, 26]. Optimism exercises, including “best possible self” and cognitive reframing tasks, likely promoted a sense of control and efficacy, enabling participants to interpret challenges as manageable rather than catastrophic [12, 14]. The integration of these exercises within group sessions may also have strengthened their effects through shared reflection and peer support, echoing findings from Rashid and Seligman’s [36] positive psychotherapy research.

At the practical level, these findings underscore the feasibility of implementing brief, low-cost interventions that address both protective and risk factors for mental health within university settings. Gratitude and optimism exercises are simple, culturally adaptable, and easily integrated into existing mental health and wellness programs. Universities could embed such practices into student orientation sessions, counseling services, or digital platforms to reach a larger audience. Because the intervention is preventive and scalable, it can complement existing clinical treatments by promoting resilience and reducing the incidence of mental health crises that often precede suicidal ideation. These findings are also consistent with earlier prevention-focused approaches applying positive psychology to vulnerable populations [51].

Social and emotional mechanisms

Potential mechanisms discussed in the positive psychology literature include improved emotion regulation, enhanced social connectedness, and stronger future-oriented coping. In the present study, these mechanisms were not directly assessed; therefore, we present them as plausible interpretations rather than demonstrated mediators. Future trials should incorporate mediator measures (e.g., validated emotion regulation and social support scales) and test indirect effects using longitudinal mediation models.

Cultural and implementation considerations

Cultural context may influence how gratitude and optimism are expressed and internalized. As Chen et al. [37] suggested, collectivist societies may experience gratitude more relationally, focused on reciprocity and group harmony, whereas individualist cultures may emphasize personal growth and self-reflection. These nuances should inform how interventions are adapted for different populations. The mode of delivery also matters, while face-to-face workshops foster engagement and accountability, digital or hybrid formats may increase accessibility. Future implementations could leverage technology to maintain adherence and extend program reach while preserving interpersonal elements through guided facilitation.

Limitations and future research

Despite its strengths, this study has limitations. The quasi-experimental design precludes strong causal inferences, and reliance on self-report measures introduces potential bias. The absence of long-term follow-up limits conclusions about sustained effects. Future research should employ randomized controlled trials and longitudinal designs to assess durability of change and explore mediating pathways such as emotional regulation, cognitive reappraisal, and social connectedness. Cross-cultural replications are also needed to examine generalizability. Furthermore, the inclusion of physiological or behavioral indicators could enrich understanding of how gratitude and optimism influence stress responses and mental health outcomes.

Conclusion

Overall, the findings demonstrate that cultivating gratitude and optimism through structured, brief interventions can meaningfully enhance psychological well-being and reduce suicide-risk factors among university students. By promoting adaptive coping, emotional regulation, and social connectedness, these interventions address both the affective and cognitive dimensions of resilience. The observed interdependence between increases in gratitude and optimism and decreases in depression and suicidality underscores their potential as complementary components in preventive mental health strategies. Integrating positive psychology interventions into university programs offers a scalable, evidence-based approach to fostering resilience, reducing suicide risk, and cultivating a thriving academic environment.

Authors’ contributions

NSA had a lead role in conceptualization, methodology, formal analyses, developing the original draft, and revising the final draft. ERSI had a lead role in methodology and data collection, and contributed to conceptualization, formal analyses, and reviewing/editing drafts. LMSR, LPC and BMK contributed to conceptualization, methodology, and reviewing/editing drafts.

Funding

This research was supported by the University of Málaga through its Internal Plan for Research, Transfer, and Scientific Dissemination (ref. JAB107).

Data availability

For information regarding access to the data associated with the present study, please contact the author.

Declarations

Ethics approval and consent to participate

The study protocol and study methodology was approved by ethic committees in University of Málaga Institutional Review Board (161-2023-H) and followed the Declaration of Helsinki (2013). All participants gave written informed consent; in case of the inability to give written consent, a legal representative had to provide consent.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.