The Effect of Anhedonia on Suicidal Ideation: The Moderated Mediation Effect of Emotional Intelligence Through Loneliness

Article information

Psychiatry Investig. 2025;22(5):591-601

Publication date (electronic) : 2025 May 15

doi : https://doi.org/10.30773/pi.2024.0388

Seonghee Lee¹, Sung-Man Bae^,1,2

¹Department of Psychology, Graduate School, Dankook University, Cheonan, Republic of Korea

²Department of Psychology and Psychotherapy, College of Health Science, Dankook University, Cheonan, Republic of Korea

Correspondence: Sung-Man Bae, PhD Department of Psychology and Psychotherapy, College of Health Science, Dankook University, 119 Dandae-ro, Dongnam-gu, Cheonan 31116, Republic of Korea Tel: +82-41-550-8142, E-mail: spirit73@dankook.ac.kr

Received 2025 January 5; Accepted 2025 March 31.

Abstract

INTRODUCTION

The WHO’s 2021 report on National Suicide Prevention Strategies states that around 700,000 individuals die by suicide each year [1]. Additionally, one in 10 adults considers suicide at least once in their lifetime [2]. Although suicidal ideation does not necessarily lead to suicide attempts or behaviors, it can be a significant factor in predicting and preventing suicide, considering that it is an early stage on the continuum of suicidal behavior [3].

Major risk factors for suicidal ideation include depression, other mental disorders, family history, and substance abuse [4], with depression being a well-known risk factor for suicidal ideation. Recently, in the diagnosis of depressive disorders, low positive affect, characterized by the loss of interest and pleasure, in addition to depressed mood, has been increasingly highlighted. Anhedonia, which is closely related to low positive affect, is a core symptom in approximately 70% of all patients with depressive disorders [5]. Numerous studies have confirmed that anhedonia is strongly associated with suicidal behavior, even after controlling for the severity of depressive symptoms [6,7]. It suggests that anhedonia, independent of depression, can be a risk factor for suicidal ideation [8].

Numerous studies involving students, the public, and individuals with mental disorders have identified anhedonia as a risk factor for suicidal ideation [9,10]. Anhedonia is “a diminished emotional response or interest in stimuli that previously elicited reward or pleasure [11].” Recent meta-analyses have shown that anhedonia is a significant risk factor for suicide in both clinical and control groups [12], with a moderate effect size difference in anhedonia scores between individuals reporting suicidal ideation and those who do not [13].

Individuals reporting anhedonia lack motivation to seek positive emotions, which increases their likelihood of experiencing negative emotions [14]. Additionally, social anhedonia exhibits reduced interest in or desire for social interactions, which may lead to avoidance or withdrawal from social situations [15]. Consequently, individuals experiencing anhedonia may struggle to form meaningful interpersonal relationships and frequently experience negative emotions, such as loneliness [16,17]. A network structure analysis found a strong correlation between anhedonia and loneliness [18]. Other studies have reported that individuals experiencing social anhedonia have poor social networks and high levels of loneliness [15,16].

Loneliness is an unpleasant and distressing emotion that is subjectively experienced when the need for interpersonal relationships is frustrated or deficient [19]. According to the Ministry of Health and Welfare’s Suicide Survey (2018), 48.1% of respondents stated that “loneliness could be a reason for suicide.” Furthermore, 2019 White Paper on Suicide Prevention identified loneliness as one of the major factors prompting the consideration of suicide [20]. It indicates that loneliness is a risk factor for self-harm and suicide attempts. Systematic literature reviews have also revealed that loneliness significantly predicts suicidal ideation and behavior [21,22]. Anhedonia and loneliness are closely associated with suicidal ideation. Previous research17 found that loneliness fully mediated the relationship between social anhedonia and overall social functioning, even after controlling for negative emotions. Another study [18] revealed that individuals who experience anhedonia are more likely to experience loneliness than those who do not.

A prior study23 found that individuals reporting suicidal ideation struggled to understand, regulate, and express their emotions. Many researchers have emphasized the importance of enhancing emotional intelligence in preventing suicidal ideation [24,25]. Emotional intelligence is the ability to evaluate and express emotions of oneself and others, effectively regulate emotions, and utilize emotions. Individuals with high emotional intelligence experience less emotional distress in stressful situations, helping maintain self-esteem and self-efficacy, which mitigates the impact of adverse events [26].

Previous studies have indicated that emotional intelligence is significantly negatively related to suicidal ideation [27,28]. According to a study [29], emotional intelligence therapy for adolescents significantly improved the level of suicidal ideation. A prior study [30] found that, after controlling for gender and age, emotional intelligence weakens the influence of loneliness on suicidal ideation among adolescents experiencing cyberbullying. It suggests that emotional intelligence can interact with loneliness to influence suicidal ideation.

Individuals with high emotional intelligence tend to focus more on positive emotions by considering successful situations compared to those with low emotional intelligence [31]. They also frequently use adaptive coping strategies such as accepting others [32]. Self and other’ emotion appraisal refer to the ability to identify, evaluate, and effectively convey one’s or others’ emotions, respectively. Individuals with high emotional appraisal can detect and implement appropriate regulatory strategies for negative emotional states, such as depression and anxiety, early, and recover quickly from negative emotional experiences [33]. Some studies have shown that individuals with high emotional recognition clarity tend to have lower levels of suicidal ideation [34,35]. Recognizing one’s emotions plays a central role in mindfulness and acceptance-based psychotherapy, which helps reduce suicidal behaviors [36].

Emotion utilization refers to the capacity to comprehend and effectively apply emotional information. Previous studies indicated that emotion utilization ability is negatively correlated with suicidal ideation [27,37]. Individuals with high emotion utilization pay more attention to positive emotions by thinking of successful situations in comparison to those with low emotion utilization [31], and frequently use adaptive coping strategies, such as accepting others [32]. In a study [38], individuals with high emotion utilization were more likely to seek social support from family or friends in sad or adverse situations. Social support is known to be a protective factor against suicidal ideation [4].

Emotion regulation refers to the recognition, understanding, and control of emotions. It is a significant factor influencing suicidal ideation, and lower emotion regulation abilities are associated with increased suicidal behavior [39]. The study [40] found that emotion regulation alleviates the relationship between mental distress (a combination of psychological injury, shame, humiliation, despair, loneliness, fear, and distress) and suicidal ideation among soldiers. Individuals struggling with emotion regulation tend to experience more negative emotions because they do not use effective strategies to regulate emotions [41], which can lead to suicidal ideation.

Previous studies have confirmed the relationship between demographic variables such as gender, age, economic status, and suicidal ideation. Several studies have shown that the frequency of suicidal ideation is higher in women than in men [42,43]. It has also been found that suicidal ideation increases with age2 and that lower income levels are associated with higher suicidal ideation [44]. In particular, it has been reported that individuals with lower income levels have higher suicidal ideation regardless of gender or age group [45].

In summary, this study aimed to examine the relationship between anhedonia and suicidal ideation mediated by loneliness, controlling for gender, age, and economic status, and to investigate the specific roles of emotional intelligence and its subfactors (self-emotion appraisal, others’ emotion appraisal, emotion utilization, and emotion regulation) through a moderated mediation analysis.

METHODS

Analysis

First, frequency analysis was performed using SPSS 23.0 (IBM Corp.), to determine the demographic characteristics of the participants, and Cronbach’s α was calculated to assess the reliability of each measurement tool. Second, descriptive statistics, including mean, standard deviation, skewness, and kurtosis, were computed, and a Pearson correlation analysis was conducted. Third, the direct effects of the independent variables on the dependent variables and the indirect effects mediated by the mediator variables were tested. PROCESS Macro Model 4 was used to analyze the mediation effects, with bootstrapping employed to test the significance of the indirect effects. Bootstrapping is advantageous over traditional multiple regression because it does not assume normality of the sampling distribution and thus provides greater statistical power [50]. Fourth, the moderating effects of the moderator variables and their sub-factors were tested. For this purpose, PROCESS Macro Model 1 was used to analyze the interaction effects. Mean centering was applied to minimize multicollinearity issues. Mean centering was applied not only to minimize multicollinearity issues but also to facilitate interpretation of interaction effects at meaningful values of the moderator variable. To thoroughly examine interaction effects, the significance of simple regression lines was tested at various levels of the moderator variable (mean -1SD, mean, +1SD mean) to explore interaction effects in detail [51]. Finally, a moderated mediation analysis was conducted using PROCESS Macro Model 14. This analysis combined mediation and moderation models and was conducted if the simple mediation and moderation effects were significant [52]. The model is as shown in Figure 1.

Figure 1.

The moderated mediation effect of emotional intelligence through loneliness in the relationship between anhedonia and suicidal ideation (Model 14).

RESULTS

Correlation analysis of main variables

Descriptive statistics, including means and standard deviations, were calculated for each variable, and skewness and kurtosis were computed to verify normal distribution. A normal distribution is indicated if the absolute value of skewness is less than three and the absolute value of kurtosis is less than eight [52]. Descriptive statistics and correlations among the main variables are presented in Table 1.

Table 1.

Correlations, M, and SD among the variables (N=390)

Mediation effect of loneliness in the relationship between anhedonia and suicidal ideation

The results are presented in Table 2 and Figure 2. First, the direct effect of anhedonia on suicidal ideation (c) was significant (β=0.631, p<0.001), indicating that higher anhedonia is associated with higher suicidal ideation. Next, the effect of anhedonia on loneliness (a) was significant (β=0.730, p<0.001), showing that anhedonia significantly predicts loneliness. Lastly, after controlling for the effect of anhedonia, loneliness had a significant impact on suicidal ideation (b) (β=0.234, p<0.001). Additionally, the effect of anhedonia on suicidal ideation (c’) remained significant after controlling for loneliness, indicating partial mediation by loneliness (β=0.460, p<0.001). The significance of the mediation effect was further confirmed using bootstrapping with the PROCESS Macro. If the 95% confidence interval for the indirect effect did not include zero, the mediating effect was considered statistically significant [53]. The 95% confidence interval for the indirect effect, ranging from 0.0383 to 0.1082, did not include zero, the mediating effect was statistically significant.

Table 2.

The mediating effect of loneliness between anhedonia and suicidal ideation (N=390)

Figure 2.

Mediation effect of loneliness in the relationship between anhedonia and suicidal ideation (PROCESS Model 4). a: anhedonia on loneliness, b: loneliness on suicidal ideation, c: anhedonia on suicidal ideation. ***p<0.001.

Moderating effect of emotional intelligence on the relationship between loneliness and suicidal ideation

The analysis indicated significant interaction effects of emotional intelligence and its subfactors, suggesting a need to further examine how these interactions manifest. To test the flexibility of the simple regression lines, the values of emotional intelligence and its subfactors were set at three levels: mean -1SD, mean, and +1SD mean. Results are shown in Table 3 and Figures 3-7. In groups with low emotional intelligence or its subfactors, higher loneliness was associated with increased suicidal ideation. However, in groups with high emotional intelligence or its subfactors, the impact of loneliness on suicidal ideation decreased.

Table 3.

Significance of the simple regression lines based on the conditional values of emotional intelligence and its sub-factors (N=390)

Figure 3.

Moderation of the effect of loneliness on suicidal ideation at values of the moderator emotional intelligence (PROCESS Model 1).

Figure 4.

Moderation of the effect of loneliness on suicidal ideation at values of the moderator self-emotion appraisal (PROCESS Model 1).

Figure 5.

Moderation of the effect of loneliness on suicidal ideation at values of the moderator others’ emotion appraisal (PROCESS Model 1).

Figure 6.

Moderation of the effect of loneliness on suicidal ideation at values of the moderator emotion utilization (PROCESS Model 1).

Figure 7.

Moderation of the effect of loneliness on suicidal ideation at values of the moderator emotion regulation (PROCESS Model 1).

Moderated mediation effect of emotion regulation through loneliness in the relationship between anhedonia and suicidal ideation

Anhedonia had a significant positive effect on loneliness (B=0.511, t=19.999, p<0.001) and a significant direct effect on suicidal ideation (B=0.157, t=6.054, p<0.001). Additionally, emotion regulation had a significant impact on suicidal ideation (B=-0.516, t=-4.671, p<0.001). However, the interaction effect between loneliness and the moderating variable of emotion regulation was not significant (B=-0.009, t=-1.224, p=0.222). All results are shown in Table 4.

Table 4.

Moderated mediation effect of emotional intelligence and its sub-factors (N=390)

DISCUSSION

This study examined the mediating effect of loneliness on the relationship between anhedonia and suicidal ideation, and how loneliness impacted suicidal ideation based on emotional intelligence levels. A comprehensive discussion of the results is presented below.

First, the study found that individuals with anhedonia experienced an increase in suicidal ideation. It supports previous studies showing an increase in suicidal ideation with increasing anhedonia [12,13]. A prior study [54] proposed that anhedonia is a psychological state that drives individuals to engage in suicidal behaviors to escape current stressors. From a psychosocial standpoint, suicidal ideation is a strategy for avoiding unpleasant emotions [55]. Individuals with high levels of anhedonia may be less motivated to experience pleasure and may use suicidal ideation as an experiential avoidance strategy to escape psychological pain [56].

Second, loneliness partially mediated the relationship between anhedonia and suicidal ideation. It is consistent with previous research indicating that social anhedonia affects loneliness [15,57] and that loneliness predicts suicidal ideation [22]. Individuals experiencing anhedonia show reduced interest in or need for social interactions, leading to withdrawal or isolation from the social environment. This lack of social support makes them more vulnerable to negative emotions such as loneliness. The study [17] found that loneliness mediates the relationship between social anhedonia and social functioning. Lone-liness arises from frustration with relational needs, and several studies have shown that thwarted relational needs significantly predict suicidal behavior [53,58].

Third, emotional intelligence had a significant moderating effect on the relationship between loneliness and suicidal ideation. Specifically, individuals with high emotional intelligence experienced fewer suicidal ideation than those with low emotional intelligence, even when experiencing loneliness. It supports previous research that identified emotional intelligence as a protective factor against suicidal ideation [24,25]. Emotional intelligence acts as a crucial resource for coping with stress. Individuals with high emotional intelligence are better at recognizing various emotions and minimizing the impact of negative emotions, allowing for quicker recovery and employing appropriate coping strategies, thus experiencing less psychological difficulty [59].

Emotional intelligence and its four subfactors showed significant moderating effects on the relationship between loneliness and suicidal ideation. The ability to recognize emotions helps individuals perceive whether their needs are being met and influences their choice of appropriate subsequent actions, which enhances their psychological well-being [60] Individuals with high emotional appraisal tend to attempt more problemsolving actions [61]. Emotional appraisal acts as a buffer against stress, helping maintain psychological well-being and reducing maladaptive emotion regulation styles, such as rumination, thereby increasing life satisfaction [62].

Individuals with high emotion utilization can intentionally and effectively transform negative emotions into constructive thoughts and behaviors and adapt appropriately to situations [62]. However, another study [63] found that individuals experiencing loneliness tend to struggle with emotional transformation, leading to increased anxiety, rumination, and suicidal ideation [64]. It supports the idea that individuals experiencing loneliness may remain in negative emotions longer, potentially leading to suicidal ideation.

Individuals with high emotion regulation abilities can accept and adjust to their negative emotions appropriately [31,65]. According to a previous study [66], individuals with high emotion regulation are better at managing negative emotions such as anger or anxiety. Moreover, they tend to express their feelings appropriately through interactions with others and view stressful situations positively [67]. Thus, emotion regulation skills can help individuals cope with and mitigate loneliness in interpersonal relationships and act as a protective factor against suicidal ideation.

Finally, the moderated mediation effect of emotional intelligence and its subfactors on the relationships between anhedonia, loneliness, and suicidal ideation was significant. This indicates that the impact of anhedonia on suicidal ideation through loneliness varies depending on an individual’s level of emotional intelligence and its subfactors. According to the previous study [68], emotional intelligence plays a significant role in the formation and maintenance of relationships with parents, friends, and social networks. Basic human needs include belonging to meaningful relationships or groups; when these needs are unmet, it can lead to loneliness and potentially trigger suicidal ideation [69]. High levels of emotional appraisal and utilization enable better understanding and acceptance of oneself and others, positively affecting relationship formation and reducing loneliness, which can ultimately mitigate the impact of suicidal ideation.

The implications are as follows: first, unlike previous studies that focused on negative emotions related to suicide, this study highlights anhedonia, which involves the decrease or absence of positive emotions. It clarified that anhedonia is a significant risk factor of suicidal ideation [12].

Second, although previous research has confirmed that both anhedonia and loneliness affect suicidal ideation, it has not fully explained the specific mechanisms by which anhedonia affects suicidal ideation. This study analyzed the pathways through which anhedonia affects suicidal ideation through loneliness.

Third, by confirming the moderated mediation effect of emotional intelligence and its subfactors on the relationship between anhedonia and suicidal ideation through loneliness, this study demonstrated that emotional intelligence could act as a protective factor. It suggests that emotional intelligence plays a crucial role in the pathway from anhedonia through loneliness to suicidal ideation. It can be used to develop specific suicide prevention and intervention strategies for adults experiencing anhedonia and loneliness. Emotional intelligence is an essential psychological resource that can be developed through training [70] and can serve as a key component in suicide prevention programs. By integrating programs that enhance emotional awareness, emotional expression, interpersonal skills, and stress management into suicide prevention efforts, individuals experiencing anhedonia and loneliness can be supported in gaining a deeper understanding of their emotions, improving their relationships with others, and developing more positive coping strategies.

The limitations were as follows. First, it was based on crosssectional data collected at a single time point. As this study examined the relationships among anhedonia, loneliness, suicidal ideation, and emotional intelligence at one point in time, there were limitations in asserting causal relationships between the variables. While our results suggest that anhedonia influences suicidal ideation through loneliness, alternative explanations exist. These relationships might be influenced by third variables such as depression severity, lack of social support, or interpersonal problems. These possibilities should be examined in future research. Second, this study used self-reported questionnaires to collect data, which may have been influenced by participants’ defensive attitudes or social desirability. Also, the reliance on self-report measures for all variables introduces the possibility of common method variance, which could inflate the observed relationships. Future studies should incorporate multiple assessment methods, including clinician ratings, behavioral observations, and physiological measurements, to mitigate this limitation.

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