The present study aimed to explore how the patterns of interaction between stress and positive resources differ according to the severity of depression and which resources play the most important role among the various positive resources.
The study included 1,806 people who had visited a health screening center for a mental health check-up to evaluate the levels of perceived stress, positive resources, and depressive symptoms. The participants were divided into a depressive group (n=1,642, mean age 50.60, female 68%) and a non-depressive group (n=164, mean age 48.42, female 66.6%). We conducted hierarchical regression analyses and simple slope analyses to examine the interaction between perceived stress and positive resources.
The interaction between perceived stress and optimism was significantly associated with depression in non-depressive groups. In depressive groups, the interactions between five types of positive resources (optimism, purpose in life, self-control, social support and care) and perceived stress were all significantly related to depression.
Interventions that promote optimism can be helpful for preventing inevitable stress from leading to depression. A deficiency in positive resources may be a factor in aggravating depression in stressful situations for people reporting moderate to severe depressive symptoms.
Stress is an inevitable life experience that develops when an individual fails to cope with the external physiological and cognitive distress of daily life [
Among several protective factors, personal and social resources may alleviate the negative effects of stress and depression [
Regarding the relationship between resources and depression, studies have been performed across a number of populations, including community-living older adults, adolescents, pregnant women, nurses, medical students, and patients with breast cancer, diabetes mellitus, and stroke [
It has been proven that individual resources play a buffer role in the relationship between stress and depression, but there are still many things to be elucidated for these results to have more useful clinical implications. In particular, it is important for the prevention and treatment strategies of depression in the future to clarify how the pattern of the buffering role of positive resources varies according to the severity of depression and which positive resources play the most important role among the various positive resources. The buffering role of positive resources can vary depending on the severity of depression. Many previous studies have suggested that emotion regulation and coping strategies, including resilience, may differ between people with moderate to severe depressive symptoms and those with mild or asymptomatic complaints [
The buffering effect of an individual’s resourcefulness on the relationship between perceived stress and depression has been verified in various populations, which specific resource plays a key role in the stress-depression link is still unclear. Numerous previous studies have explored various types of individual resources, such as the meaning of life, adaptive coping, and social support. However, to our knowledge, no previous study has compared the buffering effect size of various positive resources with the relationship between stress and depression.
The present study aimed to compare how the interrelationships of positive resources and perceived stress differ in the stress-depressive relationship between the group reporting moderate to severe depression and those who do not complain of mild or any symptoms. Based on previous studies, it is expected that the more severe the depression, the greater the likelihood of experiencing overall emotion regulation difficulty; therefore, various types of positive resources, including self-regulating ability, should have a greater moderating effect. It can be predicted that the positive resources at the individual level along with the degree of social support will play a significant role. In addition, this study will explore not only the difference in the moderating effect of positive resources in the two groups with different levels of depression but also which positive resource has a relatively greater moderating effect on the perceived stress-depression relationship.
The medical record of 1,806 people who visited the health-screening center at Seoul St. Mary’s Hospital and underwent a mental health check-up from between March 2015 to May 2017, was included in the present study. This study is based on medical records and conducted research in compliance with the principles of the anonymization process for personal information, and obtained IRB approval for exemption from the consent process. The study protocol was approved by the Institutional Review Board of the Ethics Committee of Seoul St. Mary’s Hospital at the Catholic University of Korea (KC16RISI0734).
The participants were asked about their demographic information, including gender, years of formal education, and marital status. We assessed the participants’ depressive symptoms using the Korean version of the Patient Heath Questionnaire-9 (PHQ-9), a multipurpose instrument for screening, diagnosing, monitoring, and measuring the severity of depression. The PHQ-9 consists of 9 items; respondents rate the frequency of the symptoms using a scoring severity index from 0–3. PHQ-9 scores of 5, 10, 15 and represent mild, moderate, and severe depression [
Stress levels were measured by the Perceived Stress Scale (PSS). The PSS is a self-report instrument that evaluates the level of perceived stress during the previous month. This scale consists of 10 items that ask about the frequency of thoughts and feelings experienced using a Likert-type scale with five response options, between 0 (never) and 4 (very often). The total scale score is the sum of all the items and ranges between 0 and 40; higher scores correspond to higher levels of perceived stress.3 In the present sample, the Cronbach alpha for the PSS was 0.79.
Positive resources were assessed using the Positive Resources Test (POREST), a self-report questionnaire for assessing an individual’s positive resources in a clinical setting. The POREST measures five multi-dimensional positive resources: optimism, purpose/hope, self-control, social support, and care. The test comprises 23 items, and each is rated on a 5-point scale (from 1=not true to 5=very true) [
Our main predictive variable was the severity of depressive symptoms. The moderating variables included five types of positive resources, and the dependent variables were the severity of perceived stress. Age, sex, marital status, and years of education were the control variables (
To test for a moderation effect, we performed a hierarchical regression analysis as suggested by Aiken and West (1991). However, when interaction terms are included in a regression model, the effect of multicollinearity may be problematic. Therefore, we produced an interaction term by mean-centering the sum of the scores of the predictive variables (perceived stress) and the moderating variable (positive resources). First, we entered the predictive and moderating variables into the model. Next, we simultaneously included the predictive variables, moderating variable, and interaction terms to examine their effects on the dependent variable. To assess the pattern of the moderation effect, we performed a simple slope analysis [
To identify whether the degree and pattern of moderation effect were different depending on the severity of depressive symptoms, the participants were divided into two groups based on the PHQ-9: a depressive group and a non-depressive group. The depressive group had aPHQ-9 score ≥10, while the nondepressive group demonstrated a PHQ-9 score <10 [
Participant demographics and clinical characteristics are presented in
In the non-depressive group, the mean PSS score was 14.70 (±7.51), and the mean PHQ score was 2.41 (±2.54). On the POREST, the mean scores for optimism, purpose/hope, self-control, social support, and care were 27.54 (±4.03), 22.78 (±3.98), 18.99 (±3.14), 11.57 (±2.12), and 7.51 (±1.50), respectively (
In the depressive group, the mean PSS score was 25.06 (±5.57), and the mean PHQ score was 13.70 (±4.23). For the POREST subscores, the mean scores for optimism, purpose/hope, self-control, social support, and care were 21.77 (±4.81), 18.63 (±4.59), 15.79 (±3.54), 9.71 (±2.61), and 7.25 (±1.76), respectively (
The correlation matrix for all variables is provided in
In the depressive group, the perceived stress was positively correlated with depressive symptoms (r=0.44, p<0.01) and negatively correlated with optimism (r=-0.53, p<0.01), purpose/hope (r=-0.29, p<0.01), self-control (r=-0.32, p<0.01), social support (r=-0.25, p<0.01), and care (r=-0.16, p<0.05). Depressive symptoms were negatively correlated with optimism (r=-0.55, p<0.01), purpose/hope (r=-0.30, p<0.01), self-control (r=-0.29, p<0.01), and social support (r=-0.31, p<0.01). The correlation between depressive symptoms and care was not significant.
In the depressive group, the interactions between perceived stress and optimism (β=-0.30, p<0.01)/purpose/hope (β=-0.20, p<0.01)/self-control (β=-0.27, p<0.01)/social support (β=-0.19, p<0.05)/care (β=-0.16, p<0.05) were significant related to the severity of depressive symptoms. A simple slope analysis showed a significantly positive association between perceived stress and depressive symptoms in the group with low (-1SD) and moderate levels of optimism. For the group with a high (+1SD) level of optimism, perceived stress was not significantly associated with depressive symptoms. In addition, our results demonstrated a significant positive relationship between perceived stress and depressive symptoms at all three different levels of purpose/hope, self-control, social support and care (Mean, Mean+1SD, Mean-1SD) (
Prior studies suggest that positive resources have a buffering effect on the relationship between perceived stress and depressive symptoms across various populations. However, few studies have investigated which specific positive resource exerts the most influence on the stress-depression link. Furthermore, based on previous studies about the general emotion regulation ability of depression, it is possible that the moderation effect of positive resources appears different between mild and moderate to severe depression. In this context, the present study compared how the interactions of perceived stress and positive resources differ between the group reporting moderate to severe depression and that which complain of mild or no significant symptoms. In addition, we explored which positive resource had a relatively greater interaction effect with perceived stress by calculating and comparing the effect size of various positive resources.
In the present study, the interaction between optimism and perceived stress showed the largest moderation effect size among various positive resources on depressive symptoms. The interaction effect was significant in both the depressive and the non-depressive group. Consistent with previous results, the present finding suggests that optimism is an elastic resource that people use to deal with stressful events [
The interactions between perceived stress and purpose and hope/self-control/social support/care showed significant association with depressive symptoms, which appeared limited in people reporting moderate to severe depressive symptoms. Purpose and hope refers to how coherent, purposeful, and significant a person feels in his or her life regarding personal growth, meaning/value in life, and spirituality [
Self-control is the ability to manage and care for oneself, which is related to autonomy, self-efficacy, concentration, and exercise. One’s self-control ability is a positive resource that involves an adaptive cognitive emotion regulation strategy, such as positive reappraisal, positive refocusing, a refocus on planning, and acceptance. Recent research has suggested that difficulties in self-regulation after experiencing negative life events may contribute to the risk for the onset of depression. Indeed, evidence indicates that depressed patients exhibit more frequent use of maladaptive strategies when regulating affect and show difficulties effectively implementing adaptive strategies [
Social support has been one of the most widely studied psychosocial factors in relation to health and disease [
Previous studies reporting a relationship between care-giving behavior and depression showed mixed results. Several previous studies reported that care-giving behavior especially financial support for others was harmful for major depression [
Overall, in the present study, the moderation effect size of positive resources in the relationship between stress and depression was small and was inferred using the Cohen’s ƒ2. According to the diathesis-stress model, adverse experiences have a particular depressing effect on vulnerable individuals [
This study had several limitations. First, this was a crosssectional study that concurrently obtained measurements. To establish causal relationships, there is a need for future longitudinal studies that follow the depressive symptoms of people who have experienced recent stressful events. In particular, prospective studies that serially assess perceived stress, positive resources, and depressive symptoms after a recent stressful life event would be informative. Another limitation of this study is that all variables, including positive resources, were assessed by self-reports. It is possible that the mental representations of positive resources were distorted depending on the severity of the depressive symptoms. Severely depressed individuals might have a tendency to devaluate their positive resources. In addition, the present study was based on a database of information collected from people examined at a health screening center, and the unique characteristics of these people may differ from the community and clinical population and therefore could have influenced the overall results. For example, those who pay for time and money and undergo medical check-ups may have a high overall interest in their own health and a high socio-economic level. In this study, we tried to control possible demographic variables, such as age, gender, and education level, but the results should be interpreted with caution considering that the characteristics of the participants likely influenced the study. Further, the relationship between stress, positive resources, and depression is likely to be influenced by a variety of factors, including age, gender, educational level, marital status, as well as other psychiatric symptoms and emotional control factors. In the future, an in-depth study that explores the relationship between various variables related to stress, positive resources, and depression through Bayesian network analysis would be helpful in overcoming the limitations of the present study.
Among diverse personal and social positive resources, the interaction of optimism and perceived stress showed the greatest association with the depression. In addition, the interactions of self-control/purpose & hope/social support/care and perceived stress exerted a significant interaction effect on the group reporting moderate to severe depression. The findings of this study suggest that interventions promoting positive resources, such as optimism, can be helpful in protecting inevitable stress from leading to depression. Particularly for people suffering from moderate or severe depressive symptoms, a deficiency in positive resources can aggravate depression in stressful situations.
This work was supported by a grant from the Choi Shin-Hai Neuropsychiatric Research Fund of the Korean Neuropsychiatric Association.
The authors have no potential conflicts of interest to disclose.
Conceptualization: Hyu Jung Huh, Jeong-Ho Chae. Data curation: Jeon Ho Chae. Formal analysis: Hyu Jung Huh, Kyung Hee Kim, Hee-Kyung Lee. Funding acquisition: Hyu Jung Huh. Investigation: Hyu Jung Huh, Bo Ram Jeong, Ji Hyun Hwang, Jeong-Ho Chae. Project administration: Hyu Jung Huh, Jeong Ho Chae. Resources: Jeong-Ho Chae. Software: Jeong-Ho Chae. Supervi sion: Jeong-Ho Chae. Validation: Jeong-Ho Chae. Visualization: Hyu Jung Huh. Writing—original draft: Hyu Jung Huh. Writing—review & editing: Bo Ram Jeong, Ji Hyun Hwang, Jeong-Ho Chae.
Hypothesized model about interrelation among perceived stress, positive resources and depressive symptoms.
Interaction effect of perceived stress and positive resources on depressive symptoms in non-depressive group.
Interaction effect of perceived stress and positive resources on depressive symptoms in depressive group.
Demographic characteristics of participants
Characteristic | Mean (SD)/% |
Mean (SD)/% |
Skewness | Kurtosis | Mean (SD)/% |
Skewness | Kurtosis |
---|---|---|---|---|---|---|---|
Total group | Depressive group | Non-depressive group | |||||
Age | 50 (16.55) | 48.32 (11.48) | 50.60 (16.96) | ||||
Gender (female) | 68% | 81.7% | 66.6% | ||||
Educational year | 15.16 (2.39) | 15.03 (2.16) | 14.46 (2.46) | ||||
Marital status (married/cohabited) | 78.9% | 78.7% | 78.9% | ||||
Perceived stress (PSS) | 15.64 (7.93) | 25.06 (5.57) | -0.60 | 0.06 | 14.70 (7.51) | -0.12 | 0.37 |
Depression (PHQ-9) | 3.43 (4.24) | 13.70 (4.23) | 0.90 | -0.21 | 2.41(2.54) | 1.47 | 1.57 |
Positive resources (POREST_total) | 87.01(12.77) | 73.15 (13.35) | -0.19 | -0.18 | 88.40 (11.85) | -0.37 | 1.12 |
Optimism | 27.02 (4.43) | 21.77 (4.81) | -0.29 | -0.03 | 27.54 (4.03) | -0.52 | 0.37 |
Purpose & hope | 22.41 (4.21) | 18.63 (4.59) | -0.26 | -0.11 | 22.78 (3.98) | -0.16 | 0.01 |
Self-control | 18.70 (3.31) | 15.79 (3.54) | -0.20 | -0.27 | 18.99 (3.14) | -0.15 | 0.08 |
Social support | 11.40 (2.24) | 9.71 (2.61) | -0.41 | 0.05 | 11.57 (2.12) | -0.29 | -0.26 |
Care | 7.49 (1.53) | 7.25 (1.76) | -0.13 | -0.23 | 7.51 (1.50) | -0.31 | -0.21 |
PSS: Perceived Stress Scale, PHQ-9: Patient Health Questionnaire-9, POREST: Posive Resource Test
Correlation among perceived stress, positive resources and depression
1 | 2 | 3 | 4 | 5 | 6 | 7 | |
---|---|---|---|---|---|---|---|
1. Perceived stress | -0.53 |
-0.29 |
-0.32 |
-0.25 |
-0.16 |
0.44 |
|
2. Optimism | -0.23 |
0.63 |
0.50 |
0.49 |
0.24 |
-0.55 |
|
3. Purpose & hope | -0.21 |
0.64 |
0.62 |
0.50 |
0.39 |
-0.30 |
|
4. Self-control | -0.20 |
0.58 |
0.65 |
0.32 |
0.27 |
-0.29 |
|
5. Social support | -0.15 |
0.62 |
0.53 |
0.46 |
0.26 |
-0.31 |
|
6. Care | -0.14 |
0.33 |
0.41 |
0.34 |
0.38 |
-0.09 | |
7. Depression | 0.55 |
-0.31 |
-0.27 |
-0.26 |
-0.20 |
-0.11 |
The top of the diagonal is the correlation of the depression group, the bottom of the diagonal is the correlation of the non-depressed group. The mean and standard deviation values in parentheses are the mean and standard deviation of the depressed group. The values outside the parentheses of the mean and standard deviation are the mean and standard deviation of the non-depressed group.
p<0.05,
p<0.01
Interaction effect of positive resources and perceived stress on two dimensions of depression
Depressive group |
Non-depressive group |
|||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Severity of depressive symptoms |
||||||||||||||
B | β | t | R2 | ΔR2 | F | Cohen’sƒ2 | B | β | t | R2 | ΔR2 | F | Cohen’s ƒ2 | |
Constant | 13.29 | 4.81 |
0.08 | 17.91 |
0.15 | 3.51 | 7.20 |
0.00 | 77.73 |
0.00 | ||||
Perceived stress (X) | 0.16 | 0.22 | 2.72 |
0.38 | 0.16 | 0.37 | 14.18 |
0.28 | ||||||
Optimism (Z) | -0.40 | -0.45 | -5.67 |
-0.14 | -0.21 | -8.12 |
||||||||
XZ | -0.04 | -0.30 | -4.82 |
0.46 | -0.01 | -0.07 | -2.81 |
0.28 | ||||||
Constant | 13.04 | 4.35 |
0.04 | 9.73 |
0.06 | 3.66 | 7.43 |
0.00 | 70.85 |
- | ||||
Perceived stress (X) | 0.31 | 0.41 | 5.45 |
0.28 | 0.18 | 0.41 | 16.89 |
0.27 | ||||||
Purpose & hope (Z) | -0.19 | -0.20 | -2.62 |
-0.10 | -0.15 | -6.11 |
||||||||
XZ | -0.03 | -0.21 | -3.08 |
0.32 | 0.00 | -0.02 | -0.71 | 0.27 | ||||||
Constant | 12.46 | 4.09 |
0.07 | 10.86 |
0.12 | 3.70 | 7.50 |
0.00 | 70.27 |
- | ||||
Perceived stress (X) | 0.31 | 0.41 | 5.38 |
0.27 | 0.18 | 0.41 | 16.75 |
0.26 | ||||||
Self-control (Z) | -0.23 | -0.19 | -2.50 |
-0.12 | -0.14 | -5.78 |
||||||||
XZ | -0.05 | -0.27 | -3.98 |
0.34 | 0.00 | -0.03 | -1.14 | 0.26 | ||||||
Constant | 13.76 | 4.60 |
0.04 | 9.10 |
0.06 | 3.83 | 7.77 |
0.00 | 67.97 |
- | ||||
Perceived stress (X) | 0.32 | 0.42 | 5.63 |
0.27 | 0.19 | 0.43 | 17.44 |
0.26 | ||||||
Social support(Z) | -0.29 | -0.18 | -2.39 |
-0.14 | -0.12 | -4.75 |
||||||||
XZ | -0.05 | -0.19 | -2.72 |
0.31 | 0.00 | 0.01 | 0.34 | 0.26 | ||||||
Constant | 13.97 | 4.57 |
0.03 | 7.51 |
0.04 | 4.00 | 8.07 |
0.00 | 64.02 |
- | ||||
Perceived stress (X) | 0.35 | 0.47 | 6.33 |
0.24 | 0.20 | 0.46 | 19.06 |
0.25 | ||||||
Care (Z) | -0.05 | -0.02 | -0.26 | -0.05 | -0.03 | -1.14 | ||||||||
XZ | -0.06 | -0.16 | -2.21 |
0.27 | 0.00 | -0.02 | -0.65 | 0.25 |
p<0.05,
p<0.01
Simple slope analysis about moderation effect of positive resources in the relationship between perceived stress and depression
b | SE | t | LLCI(b) | ULCI(b) | |
---|---|---|---|---|---|
Non depressive group | |||||
Optimism | |||||
-1SD | 0.18 | 0.01 | 13.26 | 0.16 | 0.21 |
M | 0.16 | 0.01 | 13.71 | 0.13 | 0.18 |
+1SD | 0.13 | 0.02 | 8.28 | 0.10 | 0.16 |
Depressive group | |||||
Optimism | |||||
-1SD | 0.36 | 0.07 | 5.15 | 0.22 | 0.50 |
M | 0.17 | 0.06 | 2.99 | 0.06 | 0.28 |
+1SD | -0.02 | 0.07 | -0.34 | -0.15 | 0.11 |
Purpose & hope | |||||
-1SD | 0.44 | 0.07 | 6.23 | 0.30 | 0.58 |
M | 0.31 | 0.05 | 5.54 | 0.20 | 0.42 |
+1SD | 0.18 | 0.07 | 2.52 | 0.04 | 0.32 |
Self-control | |||||
-1SD | 0.50 | 0.07 | 6.81 | 0.35 | 0.64 |
M | 0.34 | 0.06 | 6.05 | 0.23 | 0.44 |
+1SD | 0.17 | 0.06 | 2.65 | 0.04 | 0.30 |
Social support | |||||
-1SD | 0.45 | 0.08 | 6.00 | 0.30 | 0.60 |
M | 0.33 | 0.06 | 5.85 | 0.22 | 0.44 |
+1SD | 0.20 | 0.07 | 2.78 | 0.06 | 0.34 |
Care | |||||
-1SD | 0.48 | 0.08 | 6.03 | 0.32 | 0.63 |
M | 0.37 | 0.06 | 6.65 | 0.26 | 0.49 |
+1SD | 0.27 | 0.07 | 4.11 | 0.14 | 0.40 |