A Diary Study of the Within-Person Associations Between Daily Stressors and Negative Affect Among Post-Secondary Students With Recent Nonsuicidal Self-Injury Engagement

Exposure to stressors is known to lead to psychological impairment over time. However, the proximal relation between stressors and distress remains unclear, particularly among emerging adults with existing mental health concerns. Using daily diary methods, we explored the associations between five subtypes of daily stressors and negative affect among 160 post-secondary students with recent nonsuicidal self-injury engagement. We also examined whether this relation was moderated by coping strategies. We found a robust relation between daily stressors and negative affect, such that in most same-day and next-day models, relative increases in daily stressors led to increased negative affect. In contrast, we found that heightened negative affect only predicted daily stressor occurrence in same-day models. Problem-focused and socially-supported coping moderated the effect between social mistreatment and distress. Findings emphasize the need to adopt stress mitigation strategies in post-secondary contexts, as stressors may contribute to ongoing distress among students with mental health concerns.


Introduction
The post-secondary years are often associated with heightened stress for emerging adults (ages 18 -29 years old) (Linden & Stuart, 2020).Theoretical models underscore that exposure to significant life stressors may lead to chronic and impairing psychopathology (i.e., stress-diathesis) and that this impairment may further exacerbate life stressors over time (i.e., stress generation; Liu & Alloy, 2010).However, less is known about the role of daily stressors in negative affect, which may contribute to more enduring developmental processes over time.Understanding the association between daily stressors and negative affect among students with existing mental health concerns is also critical, as these students experience greater frequency of stressors (Ewing & Hamza, 2023) and may have a more challenging time managing stressors (van der Stouwe et al., 2019).Moreover, elucidating the saliency of different types of stressors, and for whom the relation between stressors and distress may be most pronounced, is critical to targeting pathways to stress and distress among post-secondary students.

Exposure to Stressors and Distress
It is well established that exposure to heightened life stressors has a significant impact on psychopathology among emerging adults in post-secondary settings (Acharya et al., 2018;Linden & Stuart, 2020).In post-secondary student samples, ongoing stressors contribute to heightened risk for anxiety, depression, and nonsuicidal self-injury, and can have a substantial detrimental impact on students' academic performance (Duffy et al., 2020;Linden & Stuart, 2020).Theory on stress and coping suggests that the association between exposure to stressors and distress is likely bidirectional.More specifically, stress-diathesis theory (Monroe & Simons, 1991) underscores that exposure to stressors may lead to heightened distress, and stress generation theory suggests that experiencing mental health concerns may lead to stressors (e.g., experiencing interpersonal challenges) (Liu & Alloy, 2010).For example, in a systematic review, Liu and Alloy (2010) found that individuals with depression experienced stressors resulting from their depressive symptoms (e.g., behavioral symptoms); in turn, exposure to stressors exasperated depressive symptoms.It is also important to consider the impact of coping strategies, as coping behavior may act as an important moderator on the relation between life stressors and distress, such that when an individual's coping resources are taxed, this is likely to further exacerbate stress and the individual's mental health challenges (for review see Zimmer-Gembeck & Skinner, 2016) Although the relation between life stressors and distress are well-established, important gaps remain in understanding the association between daily stressors and distress.Daily stressors, defined as "minor but frequent occurrences arising out of normal day to day living" (Almeida et al., 2022, p. 2), have received less attention in literature.However, daily stressors are hypothesized to be an important mechanism through which major stressful life events exert their influence on distress, in addition to maintaining independent predictive effects (Wright et al., 2020).Daily stressors are also highly relevant to post-secondary contexts, as emerging adults report the highest levels of daily stress exposure, and respond to daily stressors with greater reactivity, when compared to older adults (Almeida et al., 2022).Emerging evidence underscores that daily stressors may lead to heighten depressive and anxious symptoms among emerging adults (Connolly & Alloy, 2017;Gunthert et al., 2002;Howland et al., 2017), but less is known about the impacts of daily stressors specifically among post-secondary students, the role of different types of stressors, or the effects of distress on daily stressors (i.e., potential bidirectional relations).For example, research suggests that academic stressors may be perceived as particularly stressful for post-secondary students (Linden et al., 2022), but research has yet to explore different stressors in relation to distress among students in their daily lives.

Within-Person Associations Between Daily Stressors and Distress
Much of the literature on stressors and distress has focused on the relation from a between-persons perspective (i.e., individuals who experience more stressors are at greater risk of heightened distress) (Schönfeld et al., 2019).Research utilizing withinperson approaches is limited, but this approach can provide new insight into the nuances in the developmental pathways connecting daily stressors to distress (Wright & Woods, 2020).Examining within-person processes can provide insight into when and how stressors lead to psychopathology.For example, research among adolescents has demonstrated that heightened internalizing symptoms are experienced following days when an individual experiences stressors beyond their typical levels (Jenness et al., 2019;Lecarie et al., 2022).Further, daily stressors have been found to have a greater impact on internalizing symptoms when individuals engage in higher levels of rumination (Connolly & Alloy, 2017) or emotion differentiation (Nook et al., 2021), relative to their typical levels.Existing literature on the within-person processes highlights the need to account for individual variability in the experience of, and response to, daily stressors.

Exposure to Stressors and Distress among Students Who Engage in Nonsuicidal Self-Injury
Clarifying the relation between daily stressors and distress may be particularly relevant among emerging adults with existing mental health concerns, as daily processes may contribute to more chronic and enduring challenges (e.g., internalizing disorders).Further, students already experiencing mental health concerns may have a more challenging time managing and mitigating stressors (van der Stouwe et al., 2019) and may experience a greater frequency of stressors (Ewing & Hamza, 2023;Liu & Alloy, 2010).Nonsuicidal selfinjury (NSSI), which refers to direct and deliberate destruction or alteration of bodily tissue without lethal intent (e.g., selfcutting, burning) (American Psychiatric Association, 2022), is a particularly prevalent mental health concern among postsecondary students as approximately 17 to 25% of students report lifetime NSSI engagement (Kiekens et al., 2023;Xiao et al., 2017).Students who engage in NSSI report heightened levels of depressive symptoms and perceived stress (Boyne & Hamza, 2022), and greater negative emotional reactions to daily stressful life events (Berghoff et al., 2022), compared to their peers who do not engage in NSSI.Understanding how students with existing NSSI engagement cope with stressors and distress may provide important new insight into the shortterm processes that exacerbate more enduring risk later (e.g., heightened engagement in NSSI and associated internalizing symptoms).

Individual Differences in Coping Strategies and Types of Life
Stressors.Theory suggests that coping strategies are enacted following encounters with stressors, and can temper the negative effects of stressors on distress through a variety of methods (Zimmer-Gembeck & Skinner, 2016).Although coping strategies are often broadly categorized based on their likelihood for aversive consequences over time (e.g., risky coping versus healthy coping), all coping strategies have the potential to reduce negative mood states in the short term (Stallman, 2020).As such, it is important to investigate a variety of coping strategies in daily contexts to understand the unique and proximal influence on stressors and negative affect for each individual (Stallman, 2020).There are likely individual and situational differences in what coping strategy an individual chooses to employ, and in the efficacy of each strategy to mitigate the affective components of stressful experiences.For example, an individual may use coping strategies that directly impact the situation (problem-focused coping), when they believe that something constructive can be done directly to alter the source or stress (Agbaria & Mokh, 2022).Yet at other times, an individual may use social supports (socially-supported coping), process and express feelings arising from the stressor (emotion-focused coping), or they may avoid the situation completely (avoidant coping).Literature on the efficacy of different coping strategies to mitigate the impact of stress on affect is largely varied, with limited consistency in the relation between specific coping strategies and psychological outcomes (Bonanno & Burton, 2013).This discrepancy in coping efficacy is likely due, in part, to variability among individuals and/or across contexts (Sutherland Charvis et al., 2023).
Gender as a Moderator of the Within-Person Associations Between Daily Stressors and Negative Affect.Gender may also be an important moderator to consider when investigating the within-person associations between daily stressors and negative affect.In post-secondary samples, females have been found to experience more stressors, appraise stressors as more severe (Linden et al., 2022), and be more susceptible to subsequent heightened distress (American College Health Association, 2019), compared to males.Further, females and males have been found to use different coping strategies when responding to daily stressors in post-secondary contexts, with females reporting more frequent use of emotion-focused strategies (e.g., venting) (Graves et al., 2021).It is therefore possible that females may report heightened negative affect in response to daily stressors, given the higher frequency of stressors experienced.

The Present Study
In the present study, daily diary methods were used to explore associations between different types of daily stressors (developmental challenges, time pressures, academic alienation, social mistreatment, and friendship problems) and negative affect, and the extent to which coping strategies moderated associations between daily stressors and negative affect.Given that students with existing mental health concerns may experience greater frequency of stressors (Ewing & Hamza, 2023) and may have a more challenging time managing stressors (van der Stouwe et al., 2019), we specifically examined associations among daily stressors, negative affect, and coping among a sample of students who recently engaged in NSSI.Based on stress diathesis theory (Monroe & Simons, 1991), we hypothesized that on days when students experienced more stressors than their typical levels, they would report higher same day and next day negative affect (H1).Based on stress generation theory (Liu & Alloy, 2010), we expected that that on days when students experienced more negative affect than their typical levels, they would report higher same day and next day stressors (H2).It was also hypothesized that academic stressors would be most strongly associated with negative affect, on the basis of findings that these stressors may be perceived as most aversive by students (H3) (Linden et al., 2022).It also was expected that gender would moderate the relation between daily stressors and distress, with females reporting a greater impact of stressors on negative affect, and negative affect on stressors, than males (H4).Lastly, though there is a limited understanding of how different coping strategies influence the within-person relations of daily stressors and distress, we hypothesized that problem-focused, emotion-focused, and socially-supported coping would be more effective at buffering the impact of daily stressors on distress than avoidant coping (H5).

Participants and Procedures
Previously collected data was utilized for the present study.The sample consisted of 160 (mage = 19.73,SD = 1.77) emerging adults from a large university in Toronto, Canada who were drawn from a larger longitudinal and daily diary study.The majority of participants identified as female (83% female, 12% male, and 5% transgendered, unsure, non-binary or agendered persons).Forty-four percent of participants identified as White, 22% as East Asian, 11% as South Asian, and 23% identified as Filipino, Latin American, Black, Arab/West Asian, South East Asian, or Aboriginal.The majority of participants (46%) were living with roommates/friends, 29% were living with parents, 17% were living alone, and 8% were living with a partner or a family member other than their parent.Over half of participants (51%) had at least one parent who had obtained a post-graduate degree, 29% had at least one parent who obtained a university undergraduate degree, 9% had at least one parent who obtained a university college diploma or trades school, and 11% had at least one parent who obtained a university high school diploma or less.
Students were made aware of the larger study through broad distribution across the host university's campus and interested students were asked to contact the lab via phone or email to be screened for eligibility.To be eligible to participate in the larger study, students had to have engaged in NSSI at least five times within the previous year and have experienced an urge to engage in engage in NSSI at least once within the previous 14 days, consistent with the DSM-5-TR assessment criteria for NSSI Disorder (American Psychiatric Association, 2022).Though the sample was specifically recruited for recent NSSI engagement, the sample also demonstrated high levels of internalizing symptoms, with 71% meeting the clinical cutoff scores for depression (CESD style score of 20 or higher; Vilagut et al., 2016) and/or anxiety (GAD-7 score of 10 or higher; Spitzer et al., 2006).Given the high rates of internalizing symptoms, the present sample reflects post-secondary students already experiencing heightened mental health concerns.
Participants were scheduled for an in-person baseline session, which took approximately one-hour and included a series of questionnaires.At the end of the baseline session, participants were taught how to complete the daily assessments online.The daily assessments began the day after participants completed the baseline session and were sent every day for a two-week period.Each day, the daily assessments were sent via Qualtrics at 6:00am and were to be completed before 4:00pm.If a participant did not complete the survey by 2:00pm, a second reminder email was sent.The daily survey took approximately 5 minutes to complete, and asked participants to indicate the stressful life events experienced and coping strategies utilized the previous day, as well as current negative affect.To enhance compliance, the daily assessment link was sent at the same time every day, participants received a check-in email half-way through the daily diary period, and participants were contacted by the study coordinator if they missed two surveys in a row.As compensation, students who completed the in-person baseline session received $10, and students who completed at least 80% of their daily entries were awarded an additional $20.The study was approved by the University of Toronto Research Ethics Board (protocol: 35114) and active informed consent was obtained from all participants at the in-person baseline assessment.

Measures Baseline Measures
Demographic Questionnaire.Participants reported on their age in years, and their gender identity, ethnicity, living situation, and their parental level of education.

Daily Diary Measures
Stressful Life Events.Students were asked to indicate whether 49-events taken from the Inventory of College Students' Recent Life Experiences (ICSRLE) happened the previous day (0 = did not happen yesterday, 1 = happened yesterday) (Kohn et al., 1990).The ICSRLE has several subscales relevant to post-secondary students, including Developmental Challenge (e.g., "Struggling to meet your own academic standards", "Finding courses too demanding"), Time Pressure (e.g., "Not enough leisure time", "Too many things to do at once"), Academic Alienation (e.g., "Disliking your studies", "Finding course(s) uninteresting"), General Social Mistreatment (e.g., "Social rejection", "Being ignored"), and Friendship Problems (e.g., "Having your trust betrayed by a friend", "Conflicts with friends").Responses were summed, such that higher scores represented greater occurrence of stressful experiences.The ICSRLE has demonstrated strong psychometric properties among post-secondary students with recent NSSI engagement (Simone & Hamza, 2021).
Negative Affect.Each morning, students were asked to indicate the extent to which they were experiencing different feelings and emotions that day.Students were presented with the negative affect subscale from the Positive and Negative Affect Scale -Expanded (PANAS-X) (Watson & Clark, 1994).The General Negative Affect subscale includes 10 emotions ("afraid", "scared", "nervous", "jittery", "guilty", "ashamed", "irritable", "hostile", "upset", "distressed").Students were asked to rate how much they were experiencing each emotion on a scale from 1 (very slightly or not at all) to 5 (extremely).Responses were averaged across all 10 items such that higher scores represented greater negative affect.The General Negative Affect subscale demonstrates strong psychometric properties in daily diary studies among individuals with mental health concerns (Haney et al., 2023).NSSI Behaviors.Each morning, students were asked to indicate if they engaged in self-injurious behaviors the previous day.Students were presented with eleven behaviours, adapted from the Inventory of Statements About Self-Injury (ISAS) (Klonsky & Glenn, 2009), and asked to indicate how many times they engaged in each (open text response).Self-injurious behaviours included: cutting, burning, biting, carving, pinching, severe scratching, pulling hair, banging or hitting self, interfering with wound healing, rubbing skin against rough surfaces, or sticking self with needle.For examining whether the use of NSSI moderated the effect of stressors on negative affect (and vice versa), a binary variable was created to indicate NSSI engagement on the previous day (0 = did not engage in NSSI, 1 = engaged in NSSI).Previous work with emerging adult samples indicates that the ISAS has strong internal consistency, construct validity, and test-retest reliability (Kortge et al., 2013), and is consistent with previous daily diary literature on NSSI engagement (Gee et al., 2020).
Coping Behaviors.Students were asked to indicate how they responded to stressful life events they experienced the previous day using the Brief COPE (Carver, 1997).Students indicated to what extent they did 28 different items on a scale from 1 (I haven't been doing this at all) to 4 (I've been doing this a lot).Four subscales were created from the Brief COPE, including Problem-Focused Coping (e.g., "I've been trying to take action to make the situation better"), Emotion-Focused Coping (e.g., "I've been learning to live with it"), Avoidant Coping (e.g., "I've been refusing to believe that it has happened"), and Socially-Supported Coping (e.g., "I've been getting help and advice from other people").Responses were averaged for each subscale, such that higher scores represented greater utilization of each coping strategy.The four subscales of the Brief COPE have been previously validated in postsecondary student samples, particularly among students who engage in NSSI (Cramer et al., 2020).

Data Analyses
We conceptualized the data as a two-level hierarchical data structure in which daily assessments were nested within persons.To appropriately separate the within-and between-person variability, a series of multilevel models (MLM) were run using the HLM 7 software (Raudenbush et al., 2011).In all analyses, the level-1 predictors were entered as group-mean centered, such that the individual's average level of the predictor was the reference point for estimating relations (Enders & Tofighi, 2007).All slopes and intercepts were modeled as randomly varying based on statistically significant error terms across the model building process.The model building process began with an unconditional model to capture descriptive statistics, the intraclass correlation coefficient (ICC), and to understand the distribution of variances.Level-1 predictors were then added one at a time and evaluated based on their contribution to the model.Once the level-1 model was finalized, level-2 predictors were added.Following guidelines established by Nezlek (2011), tests of within-level moderation were conducted by creating an interaction term between daily stress and each coping strategy.The interaction term was created by centering daily scores on each participant's mean score across the 14-day period, and then multiplying the centered daily stress score by the centered daily coping strategy score.The interaction term was then added to the model uncentered.
There was very minimal missing data within daily survey responses (=< .1%)and we were able to compute composite scores for all daily diary measures based on responses provided; as such, missing daily diary data was not imputed.Equations for each model can be found below.It is important to note that only within-person equations are presented.Between-person equations (i.e., level-2) are only presented where relevant.

Descriptive Statistics
Daily diary adherence was high, with participants completing 88.6% (12.4/14) surveys on average.Students reported 7.37 daily stressors, on average.The most reported stressors were time pressure (e.g., "not enough leisure time") and developmental challenges (e.g., "struggling to meet your own academic standards").On an average day, students reported minimal negative affect (mean negative affect = 1.99, corresponding to experiencing "a little" negative affect that day).Students indicated using problem-focused coping most frequently over the daily diary period, followed by sociallysupported coping, emotion-focused coping, and avoidant coping.Approximately half of the students (51%) reported engaging in NSSI at least once over the 14 days of daily assessments.Frequency of daily stressors, negative affect, coping strategies and NSSI all significantly varied over the daily diary period.Multilevel descriptive statistics are reported in Table 1.

Reliability Analyses
Before conducting the analyses, the reliability of each daily measure was assessed.Reliability assessments were conceptualized as three-level hierarchical data structures, in which items for a measure were nested within days and days were nested within persons.All reliabilities are presented in Table 1.
It is important to highlight that reliability of scales in daily diary studies tend to be lower than the reliability of trait level measures.See Nezlek (2017) for a review on assessing reliability in daily diary contexts.Three types of stressors (academic alienation, romantic problems, assorted annoyances) and the emotion coping strategy were omitted from analyses as reliability was low for all four subscales.

Same-Day and Next-Day Effects of Daily Stressors on Daily Negative Affect
First, we examined the effect of types of daily stressors on same day and next-day negative affect.All next-day models controlled for the previous day's level of negative affect.An example of the model using total stressors is presented below.

Same-day NA
The results of these analyses are presented in Table 2. Same-day and next-day relations between stressors and negative affect were significant for all types of daily stressors, except for friendship problems stressors on same-day negative affect.On days when students experienced more daily stressors, their negative affect was higher than it was on days when they experienced less daily stressors.Similarly, there were significant lagged effects from stressors to negative affect, such that greater daily stressors on day t -1 was associated with increased negative affect on day t, controlling for negative affect on day t -1.
Demographic Factors as a Moderator.To follow up on the above results, we examined if gender moderated the effect of types of daily stressors on same-day and next-day negative affect.The same model was utilized, with an addition of a between-person (level-2) factor.An example of the model using total stressors and gender as a moderating factor is presented below.

Same-day
Within-person : Between-person : Between-person: The results of these analyses are presented in Table 3. Gender significantly moderated the relation between total stressors and negative affect and developmental challenge stress and negative affect, such that total stressors were less impactful on next day negative affect for males than for females.

Same-Day and Next-Day Effects of Daily Negative Affect on Daily
Stressors.Next, we examined the effect of daily negative affect on types of daily stressors in same-day and next-day models.All nextday models controlled for the previous day's level of stressors.An example of the model using total stressors is presented below.

Same-day Total Stress
The results of these analyses are presented in Table 4. On days when students experienced more negative affect, they also experienced greater levels of stressors than on days when they experienced less negative affect.However, there were only significant lagged effects from negative affect to next-day time pressure stressors, as negative affect did not predict nextday stressors for any other stressor subtype.
Demographic Factors as a Moderator.To follow up on the above results, we examined if gender moderated the effect of negative affect on same-day and next-day stressors.The same model was utilized, with an addition of a between-person (level-2) factor.An example of the model using total stressors and gender as a moderating factor is presented below.

Within-person : Total Stress
Between-person : Gender did not significantly moderate the effect of negative affect on same-day or next-day stressors for any of the stressors assessed.

Coping Strategies as a Buffer of the Effect of Daily Stressors on Daily Negative Affect
The next set of analyses examined if the lagged relations between types of stressors and negative affect varied as a function of daily coping strategies. 1 Two analytic approaches were utilized, as one set of coping strategies were assessed as continuous variables (problem-focused, emotion-focused, socially-supported, and avoidant coping) and one coping strategy was assessed as a binary variable (NSSI engagement).Same-day relations were also analyzed; however, the results were the same and only lagged results are presented below.

Continuous
Coping Strategies.Negative affect on day t was modeled as a function of a coping strategy on day t -1, stressors on t -1, and the interaction term on day t -1.An example of the model using total stressors and the problem coping strategy is presented below.296 Emerging Adulthood 12(3) The relation between daily social mistreatment stressors and next-day negative affect was significantly moderated by both problem-focused coping (B = À.07, p = .021)and socially-supported coping (B = À.07, p = .033).Significant coefficients suggest that the relation between social mistreatment stressors and negative affect was smaller on days when socialy-supported or problem-focused coping was higher than on days when it was lower, relative to an individual's typical levels.No other coping strategy significantly buffered the relation between domains of daily stressors and next-day negative affect.
Binary Coping Strategies.For this analysis, an interaction term was created by generating a dummy code for NSSI engagement, then multiplying each dummy code with the groupmean centered stressors variable.Negative affect on day t was modeled as a function of the two dummy variables, the two interaction variables, and negative affect for day t -1, as illustrated below.The buffering effect of NSSI was tested by constraining the interaction coefficients to be equal.Note that the intercept was removed from this model to avoid linear dependence. NAðday There was no significant effect of NSSI engagement on the relation between types of daily stress and next-day negative affect.However, mean negative affect was significantly higher when an individual had engaged in NSSI the previous day (M = 2.17) compared to when they did not engage in NSSI the previous day (M = 1.96),X 2 (1, n = 42) = 12.18, p < .001.
Exploratory Follow-Up Analyses.Given that few coping strategies buffered the relation between stressors and negative affect, and that stressors maintained a strong predictive effect on negative affect across all models, we conducted additional follow-up analyses.These analyses replicated the models described above but modeled next-day stressors as the outcome.We found that no coping strategy buffered the relation between stress and next-day stressors, for all types of stressors assessed.

Discussion
The purpose of the present study was to explore the proximal associations between several types of daily stressors and negative affect among a sample of postsecondary students with recent NSSI engagement.Further, we sought to explore if daily coping strategies moderated the proximal relations between daily stressors and negative affect.A robust relation between daily stressors and negative affect was found, such that in most same-day and next-day models, relative increases in daily stressors led to increased negative affect.In contrast, we found that heightened negative affect only impacted daily stressor occurrence in same-day models, except for time pressure stressors.Gender only moderated the bidirectional relation between daily stressors and negative affect for total stressors and developmental challenge domains, such that total and developmental challenge stressors were less impactful on next day negative affect for males than for females.Lastly, the four coping strategies assessed infrequently moderated the impact of daily stressors on negative affect, but there was an effect of problem-focused and socially-supported coping on the link between social mistreatment and negative affect.
Stressor Exposure as a Robust Predictor of Current and Future Negative Affect and Stressors Across many of the models, stressors maintained a strong significant impact on next day negative affect, regardless of coping strategy employed and when controlling for previous negative affect.Consistent with previous daily diary literature (Gunthert et al., 2002;Howland et al., 2017;Sch önfeld et al., 2019), this finding suggests that experiencing greater daily stressors than usual may significantly impact distress, leading to greater than average negative affect that is sustained across days.This finding offers support for stress-diathesis models (Monroe & Simons, 1991), in which stressors precipitate negative affect.Though stressors predicted heighted negative affect for both males and females, results suggest that females experienced heightened negative affect in response to certain types of daily stressors compared to males.Developmental challenges stressors (e.g., "struggling to meet your own academic stressors") were particularly impactful for females, which is consistent with broader literature on gender differences in the experience of stress related to academics (Linden et al., 2022).Friendship problems stressors were the only stressor subtype that did not predict negative affect in same-day models, though this is likely due to the low occurrence relative to other stressor subtypes (see Table 1).It is also possible that the three items included in the friendship problems subscale were not as salient for students when compared to social mistreatment stressors which captures interpersonal challenges such as social rejection.
Findings uniquely demonstrated that the effect from negative affect to stressors was less pronounced, with daily negative affect primarily predicting same-day stressors but not next-day stressors.Although the present findings suggest that stressors and negative affect co-occurred within a day, our findings did not support stressgeneration theory (Liu & Alloy, 2010).It is possible that negative affect influences stressor occurrence only in immediate contexts (i.e., within an hour), or that the effects of negative affect on stressors take longer to emerge over time.Alternatively, much of the existing literature investigating how distress contributes to stressors focuses on more clinical indicators of distress, such as depressive symptoms, and specific vulnerability factors, such as neuroticism (Liu & Alloy, 2010).It is possible that the experience of negative affect, in and of itself, is not strong enough to generate further stressful events.Another possibility is that when previous levels of stressors are accounted for the influence of negative affect on stressors is diminished, as next-day models included stressors as a control.This interpretation is further supported when considering the exploratory findings that heightened stressors significantly predicted increased stressors the following day.

Coping Efficacy and Coping Flexibility
Results indicated limited moderating effects of coping on the link between stressors and negative affect, with the exception of social mistreatment stressors.Social mistreatment stressors reflect feelings of social isolation, social rejection, and loneliness, representing interpersonal challenges that may occur in students' daily lives.The robust influence of social mistreatment on negative affect was found to be significantly moderated by two coping strategies: problem-focused and socially-supported coping.Problem-focused and socially-supported coping both involve actively trying to address and/or solve the source of the stressor by either coming up with a strategy to mitigate the stressor or getting advice from other people about how to mitigate the stressor (Carver, 1997;Cramer et al., 2020).Given that social mistreatment stressors are more controllable compared to other daily stressors assessed (e.g., finding courses uninteresting), it is possible that employing active coping strategies helped students to feel a greater sense of agency over the stressful social situations they were in, therefore reducing feelings of distress.It is also possible that engaging in socially-supported coping helped students to feel a greater sense of social support, following these heightened experiences of loneliness and rejection, that mitigated the subsequent affective impact of the stressor.The potential for problem-focused and sociallysupported coping to buffer the impact of social mistreatment on negative affect is important, as social mistreatment stress has been found to be a strong predictor of well-being over students' first year of university (Ewing & Hamza, 2023).
Nonetheless, no other coping strategy moderated the link between the remaining daily stressors and negative affect.Elements of coping flexibility, such as having a well-balanced coping profile (i.e., possessing various strategies that can be deployed at similar levels) or employing a specific strategy in response to a specific situational demand, may be a stronger indicators of students' ability to effectively cope with distress (Bonanno & Burton, 2013;Cheng et al., 2014).Therefore, students in the present sample may not be coping effectively, as they may be exploring a variety of different coping strategies at high frequency yet not utilizing strategies to target a specific stressor or the emotional response to a specific stressor.

Limitations and Implications
There are important limitations to consider in interpreting the present findings.First, the sample was largely female and identified as White, East Asian, or South Asian, and therefore may not be generalizable to other post-secondary populations.Additionally, only participants who identified as female or male were included in analyses with gender as a moderating factor, given the small proportion of participants with another gender identity in the study sample.Our sample was also not representative of the broader student sample from which it was drawn, suggesting there may have been self-selection biases (e.g., females more likely to participate in a study on NSSI than males, as females were overrepresented in the present study).Relatedly, the present sample only included students who recently engaged in NSSI; as such, the findings may not generalize to students who do not engage in NSSI.
We also did not assess students' appraisal of the daily stressors, or their perceived efficacy of different coping strategies employed, which represents an important direction for future research.In addition, daily assessments were used to capture associations between stressors and negative affect; it is possible the effects of stressors on negative affect (and vice versa) may occur over shorter intervals of time.Ecological momentary assessments (e.g., repeated assessment over hours) could provide new insight into more proximal links between stressors and negative affect.Lastly, we were unable to analyze certain types of daily stressors measured by the ICSRLE or the impact of emotion-focused coping due to low reliability.Future work may also consider assessing event-specific relationships (i.e., specific coping strategies linked to specific daily stressors), as such coping flexibility may mitigate stressors more effectively (Cheng et al., 2014).

Conclusion
The present study illustrates the robust influence that daily stressors have on distress, and to a lesser extent the potential influence of negative affect on stressors, among postsecondary students with recent NSSI engagement.These findings corroborate theoretical models on stress (i.e., diathesis-stress perspectives), emphasizing the fundamental influence of heightened stressors on negative affect.Results also highlight the challenge of effectively interrupting the relation between daily stressors and negative affect, specifically among students with recent NSSI engagement.Overall, the findings underscore the need to adopt stress mitigation strategies in post-secondary contexts, as the enduring mental health concerns reported by many post-secondary students may be linked to the high frequency of daily stressors experienced.Understanding daily associations among stressors and distress among students with a history of NSSI, can help to clarify how daily processes may ultimately contribute to more significant mental health concerns over the longer term.

Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Table 1 .
Descriptive Statistics for Daily Measures.
Note.Reliability of NSSI engagement was not calculated as it was a single-item measure.

Table 2 .
Stressors Predicting Same-Day and Next-Day Negative Affect.

Table 3 .
Moderating Effects of Demographics on Stressors Predicting Same-Day and Next-Day Negative Affect.

Table 4 .
Negative Affect Predicting Same-Day and Next-Day Stressors.
*p < .05,**p < .01,***p < .001.Note.The stress predictor in the Next Day Models refers to the specific domain of stress that is set as the outcome.