Introduction

Depression, marked by deep sadness, disinterest, and various cognitive and physical symptoms, substantially undermines individuals’ functionality across life’s spectra. The global incidence of depression surged from 172 million in 1990 to 258 million in 2017, a 49.86% increase (Liu et al. 2020). In China, the burden of depression as measured by Disability-Adjusted Life Years (DALY) — a metric that combines the impact of premature death and the extent of living with disabilities (see Murray and Lopez 1996)—has shown a significant increase. From 1990 to 2017, the age-standardized prevalence of depression per 100,000 people rose from 3224.6 to 3990.5. Concurrently, the DALY rate also escalated from 525.1 to 607.4 per 100,000, indicating that depression is not only becoming more prevalent but also more debilitating, potentially due to increases in the severity or duration of the disorder. Accompanying these figures, the 95% uncertainty intervals (UI) were 373.5 to 719.0 in 1990 and widened to 427.7 to 820.2 in 2017 (Ren et al. 2020). The widening of the UI suggests greater variability in the data (see Briggs 2000); however, the consistent increase in DALY rates across the years, despite this variability, indicates a clear upward trend. The observable increase in DALY rates and the consistent pattern observed across the dataset lend confidence to the conclusion that the burden of depression is indeed growing.

Depression’s roots are complex, intertwined with genetic, neurobiological, environmental, and, significantly, psychosocial factors (Saveanu and Nemeroff 2012). The growing acknowledgment of early life experiences and relational factors in depression’s genesis and trajectory stresses the need for a holistic research and treatment approach (Shaw and Dallos 2005). Research into intimacy with parents and trust notably advances this viewpoint, indicating how secure attachments and trusting relationships can shield against depression (Fahmi et al. 2019; Hochgraf et al. 2021; Weisskirch 2018; Yang and Bae 2022).

Despite the recognition of intimacy with parents and trust’s positive effects on psychological health, existing research lacks a cohesive theoretical framework that fully explains their interplay and impact on depression and its management. Modernization offers both opportunities and challenges for mental health, potentially leading to the erosion of close-knit family networks and the transformation of trust in an increasingly individualistic and mobile society (Wyn et al. 2012). In a world where modernization blurs the lines between Western and Eastern sociocultural landscapes (El Amine 2016), exploring the relationship between family, trust, and depression interventions becomes crucial.

In China, a society at the crossroads of significant modernization and deeply ingrained Confucian values emphasizing family harmony and social stability, the investigation into intimacy with parents, trust, and depression becomes especially poignant. Despite modernity’s push towards reshaping family structures and trust through heightened individualism and mobility, Confucian principles persistently highlight the importance of family bonds and societal trust (Yin 2003). This contrast underlines the durability of traditional values amidst societal change, suggesting that trustful familial and community relationships act as safeguards against the mental health strains introduced by modernization, shedding light on how transitioning societies balance modernity with tradition (Nilan 2008; Rosa 2010).

Literature review and theoretical framework

Literature review

Attachment theory, articulated by Bowlby and refined by Ainsworth, offers insights into how intimacy with parents shapes psychological and emotional well-being (Bowlby et al. 1992). It emphasizes early secure attachments with caregivers as foundational for development, instilling a sense of safety and trust in future relationships (Waters et al. 2005). Securely attached individuals often develop a strong self-concept, enhancing emotional regulation and adaptability (Strahan 1995). Conversely, insecure attachments may lead to distrust and insecurity, potentially exacerbating depressive symptoms (Bettmann 2006).

Attachment theory underscores the pivotal role of intimacy with parents in providing essential emotional support, aiding stress management, and curbing the buildup of negative emotions potentially leading to depression (Duchesne and Ratelle 2014; Muris et al. 2001). In environments characterized by significant intimacy with parents and security, children’s emotional requirements are satisfied, fostering the formation of secure attachments. Such attachments lay the groundwork for the development of positive characteristics, including self-esteem, self-efficacy, and optimism, all critical in averting depression (Bohn et al. 2020). Furthermore, individuals with secure attachment styles are inclined to pursue relationships with openness and trust, extending this trust beyond familial bounds to include neighbors, friends, and colleagues, thus creating a supportive social network. This network provides emotional sustenance and resources that help alleviate stress and depressive sentiments (Bubolz 2001).

Prior research has illuminated the family as a fundamental infrastructure in the formation of attachment relationships, acting as a source, utilizer, and constructor of social trust, indispensable for the cultivation and circulation of social capital. Within this symbiotic framework of social capital generation and use, the family’s role is crucial. However, earlier studies have predominantly concentrated on children and adolescents within the context of attachment theory, overlooking adults. This gap leaves the ongoing role of familial intimacy as foundational infrastructure, as individuals mature and integrate into society, unexamined, thus highlighting a theoretical void in need of elucidation.

The evolution spurred by modernity recalibrates family interactions, leading to novel expressions of intimacy and care that transcend conventional family bounds, potentially undermining age-old familial bonds and transforming intimacy with parents dynamics (Dowds 2018; Roseneil and Budgeon 2004). These changes necessitate a critical reassessment of the traditional attachment theory and its applicability to contemporary mental health challenges, especially concerning depression (Hidaka 2012). Observations suggest that, in the contemporary context of ‘home alone,’ the familial unit may no longer constitute the cornerstone of personal infrastructure (Ronald and Hirayama 2009). The foundational security traditionally provided by parents, as Bowlby theorized, encounters obstacles from modern lifestyle preferences that elevate individualism and autonomy above familial cohesion. However, in contradiction to prevailing theoretical expectations, the significance of personal relationships is poised to escalate as the societal landscape becomes increasingly fragmented and unpredictable (Allan 2001).

Modern stressors like social isolation, economic strain, and information overload can amplify depression. Attachment theory offers insight into how intimacy and trust from parental bonds can mitigate these stressors. Despite the narrative of family decline due to ‘moral individualism’, the family still plays crucial roles in supporting individual well-being (Botterill 2014). However, the effectiveness of these familial protective mechanisms against the backdrop of modern complexities deserves closer examination, suggesting a need to adapt mental health support strategies in the changing world.

Theoretical framework

This study develops a theoretical framework (Fig. 1) that melds attachment theory with modernity’s insights, aiming to dissect the intricate relationship between familial bonds and individual psychological health amidst today’s societal shifts. This framework underscores the enduring importance of intimacy with parents, asserting their continued relevance to well-being amidst the challenges posed by modernity. It highlights how such secure bonds furnish resilience against the alienation, rapid societal pace, and fragmentation typical of contemporary life, positing that the emotional support, security, and trust from these relationships serve as vital defenses against the stressors of modern existence.

Fig. 1: Theoretical framework.
figure 1

Trust mediates the relationship between intimacy with parents and depression.

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Moreover, this framework acknowledges the evolution of attachment and family dynamics in the face of modernity. It posits that while traditional family structures and expressions of intimacy might be transforming, the fundamental role of attachment as a safeguard remains crucial. The framework examines the impact of modernity on how intimacy with parents and trust are perceived and expressed, and its implications for depression risk. This nuanced framework invites a deeper exploration into how intimacy with parents can be nurtured and maintained as societal conditions evolve, ensuring that individuals continue to benefit from the protective qualities of these bonds even in the face of modern life’s complexities.

Within this theoretical construct, intimacy with parents and trust form a unified defense against depression, substantiated by extensive empirical evidence. Intimacy with parents instills a durable sense of self-worth and emotional support, enhancing resilience to life’s adversities (Johnson and Galambos 2014), while trust stemming from this intimacy expands social support networks, bolstering communal ties and engagement—key in reducing depression risk (Yoo and Córdova 2023). Cross-cultural research further underscores that, despite cultural influences on the expression of intimacy with parents and trust, their association with identity consolidation, rather than synthesis or confusion, is consistent across diverse contexts (Sugimura et al. 2018), affirming the framework’s global relevance.

Drawing on the differential mode of interpersonal association framework in China (Fei et al. 1992), kinship underpins networks for interpersonal exchanges (Yao 2009), exemplified by the ‘acquaintance society’ and encapsulated in the proverb about recognizing a ‘near neighbor’ (Xiong and Payne 2017). Trust splits into two main types: those rooted in intimate relationships and those based on social roles. Intimacy with parents and neighbors chiefly influences trust built on emotional connections (Yang 2009), whereas trust in strangers and professional social roles such as officials is shaped by societal norms and institutional frameworks (Luo and Yeh 2012). Social cognitive theory suggests trust in various social roles is formed through observation and interaction (Castelfranchi and Falcone 2010), indicating while intimacy with parents shapes trust tendencies, its impact on complex trust forms is limited. The social capital theory posits trust as crucial in social networks, extending beyond personal interactions to reflect societal structures (Bouma et al. 2008), implying intimacy with parents’ indirect role in broader societal trust.

Intimacy with parents encapsulates the richness and depth of emotional exchange between parents and children, characterized by the sharing of sentiments, mutual understanding, and support (Clayton 2014). Trust, engendered within the foundational attachment bonds with parents, significantly enhances an individual’s sense of social connectedness and support, playing a critical role in the alleviation of depression (Weisskirch 2018). The formation of trust within the intimate sphere of parent-child relations inclines individuals towards fostering positive self-views and a reinforced feeling of being comprehended and supported (Liu 2008). Engagement in such positive emotional exchanges is key in lessening experiences of solitude and helplessness, thus diminishing the likelihood of depression. Consequently, the following hypothesis is posited:

Hypothesis 1: Intimacy with parents mitigates depression through the mediation of trust in parents.

Intimacy with parents profoundly shapes not only intrafamilial relationships but also influences broader social engagements beyond the family context. Individuals reared in environments marked by high intimacy with parents are typically skilled in developing essential interpersonal abilities, notably in maintaining relationships predicated on trust (Bubolz, 2001). These competencies extend beyond familial interactions to include relations with neighbors, enhancing the likelihood of cultivating harmonious connections and reciprocal trust within local communities (Yoo et al. 2013). This dynamic is especially pertinent in the Chinese sociocultural context, where the value placed on neighborly relations is pronounced, suggesting that neighborly trust significantly benefits individual mental health (Miao et al. 2019). Based on these insights, this study proposes:

Hypothesis 2: Intimacy with parents mitigates depression through the mediation of trust in neighbors.

Intimacy with parents influences trust within close relationships but may have limited sway over trust towards strangers. The formation of trust towards strangers hinges on an individual’s cognitive evaluation of societal dynamics and expectations of others’ behavior, embodying a commitment to social justice principles, norm compliance, and institutional integrity, alongside an anticipation of consistent behavior within the larger social milieu (Dunning et al. 2014; Foddy et al. 2009; Ho and Weigelt 2005). In contrast to the direct nurturing of trust through intimacy with parents, the development of trust towards strangers requires a more profound internalization of social frameworks and cultural values, achieved through diverse social interactions and accumulated experiences (Fei et al. 1992). Intimacy with parents lays the groundwork for pro-social behavior and a general predisposition towards trust in early development (Malti et al. 2016). However, the extension of this foundational trust to include strangers is inherently limited, influenced by a multifaceted interplay of emotional components—obligatory, authentic, and self-interested—each bearing unique traits and governing interactional norms (Yeh 2010). In light of these considerations, this study proposes:

Hypothesis 3a: Intimacy with parents mitigates depression through the mediation of trust in strangers.

Hypothesis 3b: Intimacy with parents mitigates depression not through the mediation of trust in strangers.

In scrutinizing the influence of intimacy with parents and trust in specific professional entities, such as local government officials and physicians, on depressive tendencies, the interrelation appears intricate. Trust in these professional figures is substantially predicated on macro-social underpinnings like professional ethics and institutional frameworks, transcending the familial sphere’s immediate sway (Foster and Frieden 2017; Plomp and Ballast 2010). Trust in local government officials generally mirrors an individual’s confidence in and contentment with governmental and public entities, shaped by aspects like political transparency, policy efficacy, and public service quality (Kim 2010).

Similarly, trust in physicians is tied to reliance on the healthcare infrastructure and medical institutions, contingent upon medical service quality, physician competence, and adherence to medical ethics (Kanter et al. 2019). While intimacy with parents can indirectly bolster trust in these figures through the enhancement of social capital and cognitive faculties (Hochgraf et al. 2021)—manifested in augmented social communicative abilities and heightened societal engagement fostered within a nurturing familial milieu—this impact’s magnitude and immediacy substantially diminish in comparison to trust vested in parents and neighbors. In consideration of these dynamics, this study proposes:

Hypothesis 4a: Intimacy with parents mitigates depression through the mediation of trust in local government officials.

Hypothesis 4b: Intimacy with parents mitigates depression not through the mediation of trust in local government officials.

Hypothesis 5a: Intimacy with parents mitigates depression through the mediation of trust in physicians.

Hypothesis 5b: Intimacy with parents mitigates depression not through the mediation of trust in physicians.

Methods

Data

The study leverages data from the 2018 and 2020 waves of China Family Panel Studies (CFPS), a national and comprehensive social tracking survey conducted by the Institute of Social Science Survey at Peking University. Established in 2010, the CFPS initiated a baseline survey across 25 provinces, cities, and autonomous regions within China, gathering data from 14,960 households and 42,590 individuals. The scope of the survey is longitudinal, with all individuals identified in the baseline—and their subsequently born consanguineous/adopted children—becoming gene members of CFPS and, thus, subjects of persistent biennial tracking.

CFPS has successfully administered six national surveys as of the 2020 wave, maintaining a tracking success rate that is considered exemplary on a global scale, thereby affirming its substantial value for empirical research. The survey process benefits from the expertise of a cadre of trained specialists, scholars, and professional interviewers and leverages computer-assisted personal interviewing (CAPI) technology to ensure the collection of high-quality data through face-to-face interactions.

The CFPS participants, which covers 94.5% of the population across 25 provinces, cities, and autonomous regions in China, excluding Hong Kong, Macao, and Taiwan, is considered to be nationally representative. This comprehensive coverage is paramount for generalizing findings to the wider Chinese population. The participants for CFPS were meticulously chosen using a multi-stage probability sampling method, employing implicit stratification to ensure representativeness, particularly concerning geographical diversity reflective of China’s economic disparity. Each province included its capital city as an implicit stratum, with further stratification applied to account for meaningful urban-rural differences, utilizing administrative divisions such as districts, street offices, neighborhoods (urban), and counties, towns, or villages (rural). In addition, socioeconomic status, measured continuously, was used for stratification, with variables such as local per capita GDP, the proportion of non-agricultural population, or population density serving as ranking criteria based on data availability.

Sample

For the purpose of this longitudinal analysis, the study meticulously matched participants across the 2018 and 2020 waves using the unique identifiers assigned to each individual. This facilitated an in-depth examination of the variables across time to ascertain the effect of intimacy with parents on depression. Data pertaining to the independent variable were derived from the 2018 wave, while the dependent, mediating, and control variables were extracted from the 2020 wave.

Rigorous data curation was undertaken. Regarding exclusion criteria, the 2020 CFPS survey excluded individuals whose parents had passed away in the prior six months, reducing the initial pool of 25,114 individuals to 11,816 (after excluding those with deceased mothers) and subsequently to 9132 (after excluding those with deceased fathers). In the 2018 CFPS survey, from a total of 33,097 individuals, the study excluded those for whom the research question (regarding education) was inapplicable, leaving 16,128 individuals. Further exclusions were made for individuals without any work income, narrowing the field to 8404 individuals. Additionally, individuals who responded with ‘don’t know’ or were unwilling to disclose information were excluded, resulting in a final sample of 7002 individuals. The final study cohort for subsequent analysis comprised over 3048 individuals who remained from the 2018 survey, had also participated in the 2020 survey, and had provided complete responses to all questions.

The precision of this sampling and exclusion process ensures the elimination of potential biases that could arise from non-representative samples or incomplete data. By detailing these methodological steps, the study reaffirms its commitment to reliability and validity, laying a solid foundation for the statistical analysis and subsequent findings.

Measures

Independent variable: intimacy with parents

This study evaluates the intimacy with parents using the adapted 10-item Remembered Relationship with Parents (RRP10) scale, following Denollet et al. (2007). In the 2018 CFPS, participants rated their past six-month relationships with their parents regarding intimacy. The scale had separate questions for each parent, with responses ranging from 1 (not intimate at all) to 5 (very intimate). Scores from both questions were combined to represent overall parental intimacy, with higher scores indicating greater intimacy.

Dependent variable: depression

This study assesses depression using the adapted 8-item Center for Epidemiologic Studies Depression Scale (CES-D), following Radloff (1977). In the 2020 CFPS, participants were prompted to report their depressive experiences over the preceding week with 8 different statements such as: ‘I felt downhearted and blue,’ ‘I found it difficult to get going,’ ‘My sleep was restless,’ ‘I felt sad,’ ‘I felt lonely,’ ‘I felt that life was less satisfying,’ ‘I felt I could not shake off the blues,’ and ‘I felt that I could not carry on.’ The frequency of these feelings was rated on a scale from 1 to 4, where 1 represented ‘never or rarely (less than one day),’ 2 indicated ‘sometimes (1 to 2 days),’ 3 denoted ‘often (3 to 4 days),’ and 4 signified ‘most of the time (5 to 7 days).’ The responses were aggregated to create a composite score, with a Cronbach’s alpha reliability coefficient of 0.76, suggesting a reasonably high level of internal consistency. A higher total score on this scale indicated more severe depressive symptoms.

Mediating variable: trust

In this study, trust serves as the mediating variable, operationalized through the application of the Interpersonal Trust Scale developed by Rotter (1967). This scale is designed to quantify the overarching expectation that an individual’s pledge to prospective actions is dependable, as perceived by other individuals or collectives, thereby encompassing a broad spectrum of social entities. Within the ambit of the 2020 CFPS, participants were solicited to articulate their trust levels directed towards various social figures, including parents, neighbors, strangers, local governmental officials, and physicians. The assessment employed a ten-point Likert scale for responses, which spanned from 0 (indicating no trust whatsoever) to 10 (indicating utmost trust). Accordingly, a higher tally on this scale is indicative of elevated levels of trust.

Control variable

To mitigate regression inaccuracies due to unaccounted variables, this study incorporated covariates grounded in scholarly references (Bayram and Bilgel 2008; Lorant et al. 2007) in the 2020 CFPS, with a targeted rationale for each variable’s inclusion based on its potential influence on depression. Sex (0 = ‘female,’ 1 = ‘male’) was included to account for well-documented sex differences in depression prevalence. Age, as a continuous variable, was considered due to the variable risk of depression across different life stages.

Marital status is included as a categorical variable, delineated into distinct categories: 1 = ‘Unmarried,’ 2 = ‘Married,’ 3 = ‘Cohabitating,’ 4 = ‘Divorced,’ 5 = ‘Widowed.’ The inclusion of this variable is predicated on the substantial influence that marital relationships exert on emotional and social support systems. These systems are integral to individual mental health outcomes, making the nuanced understanding of marital status critical in analyzing its psychosocial impacts.

Self-rated health (1 = ‘very bad,’ 2 = ‘relatively bad,’ 3 = ‘fair,’ 4 = ‘relatively good,’ 5 = ‘very good’) captures subjective health perceptions, closely linked to mental well-being. Smoking status (0 = ‘no,’ 1 = ‘yes’) and alcohol consumption (0 = ‘no,’ 1 = ‘yes’) were controlled for due to their association with coping mechanisms for depression. Education levels (1 = ‘illiterate/semi-literate,’ 2 = ‘never attended school but not illiterate,’ 3 = ‘primary school,’ 4 = ‘junior high school,’ 5 = ‘high school/technical secondary school/vocational high school,’ 6 = ‘junior college,’ 7 = ‘undergraduate college,’ 8 = ‘master’s degree,’ 9 = ‘doctorate’) reflect socioeconomic status and access to resources, affecting mental health risks and resilience. Household registration (0 = ‘rural’, 1 = ‘urban’) was factored in to consider the urban-rural divide in access to mental health services and societal pressures.

Employment status is incorporated as a categorical variable to systematically explore the economic aspects of depression. This variable is meticulously categorized into three distinct groups: 0 = ‘unemployed,’ indicating individuals currently without work but actively seeking employment; 1 = ‘employed,’ representing those engaged in any form of paid work; and 2 = ‘out of the labor market,’ encompassing individuals not seeking employment due to various reasons such as retirement, disability, or other personal circumstances. This classification is essential for analyzing how different employment statuses influence mental health, acknowledging the complex interplay between economic activity and psychological well-being.

Annual income is included in this study as an objective measure to directly assess the economic status of individuals, represented by the actual amount earned per year. This quantifiable metric is crucial as it provides a clear indication of financial security, a key determinant of mental health. Additionally, income self-assessment, rated on a scale from 1 = ‘very low locally’ to 5 = ‘very high locally,’ complements this objective measure by capturing individuals’ subjective perceptions of their economic standing within their local environment. This subjective assessment allows the study to explore how personal feelings of economic sufficiency or deficiency relate to mental health outcomes. Both of these financial metrics are integral to addressing the economic dimensions of depression, linking financial security with psychological health.

Moreover, the inclusion of the frequency of physical exercise further enriches the study, as physical activity is widely recognized for its beneficial effects on mental health. This variable objectively measures how often individuals engage in physical activities, providing a clear indicator of their activity levels. Each variable has been carefully selected based on its empirically evidenced or theoretically plausible impact on depression, ensuring a comprehensive analysis that considers the complex interplay between socioeconomic factors and other determinants of depression.

Analytical strategy

This study employs Stata version 16.0 for all empirical analyses, utilizing a five-stage approach to unravel the mechanisms linking intimacy with parents to depression. Initially, the study examines an in-depth description of the sample characteristics, laying the groundwork for understanding the context of the data. Following this, the Spearman correlations between key variables are assessed to identify preliminary relationships and patterns. The third stage involves the application of ordered logistic (Ologit) regression to investigate the nuanced relationship between intimacy with parents and depression, providing a framework for understanding the ordinal nature of the depression variable.

Subsequently, the study adopts Structural Equation Modeling (SEM) to dissect the indirect and direct effects mediated by five distinct dimensions of interpersonal trust, offering insights into the complex interplay between intimacy with parents, trust, and depression. The final stage comprises a robustness check, wherein intimacy with parents is disaggregated into intimacy with the father and intimacy with the mother, respectively, to ascertain the consistency and reliability of the findings. Throughout this analytical journey, p-values less than 0.05 are considered to denote statistical significance, ensuring rigor and precision in the interpretation of the results.

Results

Descriptive statistics

According to Table 1, it is noted that the dataset encompasses 3048 observations for each variable, thus providing a substantial basis for robust statistical analysis. The independent variable under scrutiny is ‘Intimacy with parents,’ which manifests a mean value of 8.57, accompanied by a standard deviation of 1.38 on a scale of 2 to 10. This indicates a strong reported bond between the participants and their parents, with limited dispersion around the mean, suggesting that a majority of the participants experience a high level of intimacy with their parents.

Table 1 Descriptive statistics.
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The dependent variable, ‘Depression,’ exhibits a mean of 13.28 with a more pronounced standard deviation of 3.63 on a scale of 8 to 32. This variation suggests a wider range in the severity of depressive symptoms experienced by the participants. Mediating variables concerning trust showcase that trust in parents is considerably high, with a mean of 9.56 and a low standard deviation of 1.01, indicating a general consensus of high trust in this domain. Contrastingly, trust in strangers has a lower mean of 2.97 and the highest standard deviation of 2.14 among the trust variables, reflecting a broad spectrum of trust levels in strangers among the study participants.

Control variables such as sex demonstrate that 56.73% of the sample consists of males, while females constitute 43.27%. The average age is reported as 31.38 years with a variability of 6.60 years, which points to a middle-aged cohort due to the sample selection criteria excluded individuals whose parents had passed away. Marital status spans across a range of categories, with the majority being married (61.98%). When considering self-rated health, the mean score stands at 3.38 with a standard deviation of 0.99, indicating a general perception of fair to good health among participants. Lifestyle variables such as smoking and alcohol consumption indicate that a majority of the participants abstain from these behaviors, with 68.90% non-smokers and 89.01% non-alcohol consumers. The educational attainment of participants varies widely across the scale from 1 (illiterate/semi-literate) to 9 (doctorate), with an average educational level of 5.28, which suggests that most participants have completed high school or vocational training.

The dataset further provides insights into socioeconomic factors such as household registration, revealing a majority rural composition of 66.60%. Current employment status suggests a high employment rate within the sample at 94.36%, and the self-assessment of income denotes a moderate perception of financial standing with a mean of 2.79. Additionally, the frequency of exercise, a variable indicative of lifestyle, presents a mean of 5.86 with a standard deviation of 2.51, suggesting a moderate to high level of physical activity among the participants.

These descriptive statistics form the foundation for a comprehensive analysis, providing a window into the demographic, psychosocial, and socioeconomic characteristics of the sample, which are essential for interpreting the interplay between intimacy with parents, trust, and depression within the surveyed population.

Correlation analysis

Table 2 presents a Spearman regression analysis, revealing several notable correlations. A significant negative correlation between intimacy with parents and depression is observed, with a correlation coefficient of −0.15, which is statistically significant at the p < 0.001 level. This suggests that higher levels of intimacy with one’s parents are associated with lower levels of depression among the participants. Similarly, the trust variables, including trust in parents, neighbors, local government officials, and physicians, show significant negative correlations with depression, with coefficients ranging from −0.11 to −0.19, all significant at the p < 0.001 level. These results imply that greater trust in these figures correlates with fewer depressive symptoms.

Table 2 Spearman regression analysis.
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Interestingly, trust in strangers is notably different, presenting a smaller negative correlation with depression (−0.10, significant at p < 0.001) and showing no significant correlation with either intimacy with parents or trust in parents, indicating a distinct dynamic in the nature of trust outside of established relationships.

Ordered logistic regression analysis

Table 3 showcases an ordered logistic (Ologit) regression analysis, which is suitable when the dependent variable in question is ordinal. In this table, various coefficients represent the log odds of the levels of depression, which are in a higher-order category given a one-unit change in the predictor variable while holding other variables constant.

Table 3 Ordered logistic (Ologit) regression analysis.
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The coefficient for intimacy with parents is −0.143, with a high level of statistical significance (p < 0.001), implying that as intimacy with parents increases, the odds of being in a higher category of depression decrease. The negative sign indicates an inverse relationship, and the significance suggests that this is unlikely due to random chance.

Other notable results include the variables of marital status, self-rated health, and education, which all show significant relationships with the dependent variable. The coefficient for being married is −0.181, which is significant at the 0.05 level, suggesting that married individuals are less likely to report higher levels of depression compared to their unmarried counterparts. Divorced individuals have a coefficient of 0.455, significant at the 0.05 level, indicating they are more likely to report higher depression levels. Self-rated health has a coefficient of −0.418, highly significant at p < 0.001, indicating that better self-rated health is strongly associated with lower depression levels. Education, with a coefficient of −0.170, also significant at p < 0.001, suggests that higher educational levels are associated with lower levels of depression.

Mechanism analysis

In Table 4, Structural Equation Modeling (SEM) is adeptly employed to examine both direct and indirect factors influencing depression, unveiling the subtle dynamics between intimacy with parents, trust across varied spheres, and their collective influence on depression levels.

Table 4 Structural equation modeling (SEM) regression analysis.
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The SEM analysis elucidates a significant direct negative relationship between intimacy with parents and depression, as evidenced by a standardized coefficient of −0.229. This finding underscores the protective effect of close parental bonds on depression, demonstrating that increased intimacy with parents is associated with reduced depression.

The investigation into indirect effects through trust in different entities further diversifies the understanding. Notably, trust in parents and neighbors significantly inversely correlates with depression, with standardized coefficients of −0.028 and −0.027, respectively, indicating their potential mediating role in mitigating depression. On the other hand, trust in local government officials, physicians, and strangers is found to have smaller and non-significant indirect effects, pointing to a more nuanced or constrained influence on depression through the modeled pathways.

Robustness check

The supplementary information provided alongside the robustness checks, specifically through Supplementary Tables S1a, b, S2a, b, fortifies the study’s findings by exploring the nuances of intimacy with parents’ impact on depression and delineating the roles of mediating factors. These robustness checks are pivotal in validating the stability and reliability of the initial outcomes, ensuring that the results hold even when adjusting for different dimensions of intimacy with parents.

On the one hand, Supplementary Table S1a, b substitute ‘intimacy with parents’ with ‘intimacy with father’ and examine both the direct effects on depression and the indirect effects mediated by trust variables. The results underscore a significant negative relationship between intimacy with the father and depression, with a notable standardized coefficient indicating that deeper bonds with the father are linked to reduced depression. The indirect effects through trust in parents and neighbors further reaffirm trust’s mediating role, enhancing the protective influence against depression. This analysis showcases the robust nature of these relationships, underscoring the importance of specifying the intimacy dimensions within familial structures.

On the other hand, Supplementary Table S2a, b proceed with a similar methodology but focus on ‘intimacy with mother.’ The findings parallel those associated with the father, revealing significant negative direct effects on depression, and highlighting trust’s mediating effects. These outcomes suggest that intimacy with the mother similarly plays a critical protective role against depression, with trust variables serving as significant mediators. The consistent significance across these supplementary tables, especially in terms of the standardized coefficients and the significance levels for both direct and indirect effects, speaks to the robustness of the study’s initial conclusions.

Discussion

Finding interpretations

Navigating the complex landscape of mental health scholarship, this study investigates the relatively unexplored interplay between intimacy with parents, trust, and depression within the rapidly evolving global milieu. It unveils the critical function of intimacy with parents in mitigating depression, accentuating the role of trust in immediate relational contexts, particularly with parents and neighbors. In contrast, trust vested in broader societal roles, such as strangers, local government officials, and physicians, is delineated as having a subordinate influence on depression.

First, this study diverges from traditional research predominantly centered on children and adolescents (Clayton 2014; Liu 2008; Weisskirch 2018) by broadening its analytical lens to encompass adults aged 18–52 years. This innovative extension unveils the sustained relevance of intimacy with parents in mitigating depression across a more expansive age continuum. Such an exploration not only reaffirms the well-documented nexus between secure family bonds and mental health (Johnson and Galambos 2014; Waters et al. 2005), but also infuses new insights by underscoring its applicability into later stages of adulthood. The observed significant negative correlation between intimacy with parents and depression within this extended age bracket implies that the salutary impacts of close parent-child relations are not confined to early developmental phases but persist, influencing mental health throughout a substantial portion of the adult life course. This novel trajectory beckons a critical reassessment of attachment theory’s breadth and its pertinence (Bowlby et al. 1992), advocating for broader inclusivity of familial environmental elements in mental health discourse and intervention strategies, extending well beyond the precincts of youth and adolescence (Yoo and Córdova 2023).

Second, this study unveils a nuanced, multilayered facet of trust within social interactions, underscoring an intriguing discovery: the mediating role of trust diminishes when considering relationships with strangers, local government officials, and physicians. This unexpected outcome necessitates a deeper exploration into the mechanisms through which individuals, drawing upon trust paradigms fostered with parents, evaluate the reliability and benevolence of others and extend such evaluations to wider social interactions (Luo and Yeh 2012).

The attenuation of trust’s mediating influence in these broader contexts can be ascribed to multiple considerations. Primarily, establishing trust with strangers and specific professional figures often demands more substantial evidence and consistent positive interactions, elements that familial trust dynamics may not directly impact (Foster and Frieden 2017; Kanter et al. 2019). Furthermore, trust in professional capacities, such as those held by local government officials and physicians, is intrinsically linked to the overarching credibility of institutions and the integrity of professional conduct, factors that surpass the foundational personal trust established within familial confines (Kim 2010; Plomp and Ballast 2010). This revelation contributes a critical, scholarly insight into the intricate interplay between established familial trust and its extension into broader societal relationships, highlighting the complex dynamics at play in trust-mediated mental health outcomes.

Third, diverging from Western theoretical frameworks (Wyn et al. 2012), this study, set against the backdrop of China’s shift from traditional to modern norms (Fei et al. 1992), reveals a labyrinthine trust propagation pattern. Trust, initially fostered within familial settings, faces significant hurdles as it extends to broader societal interactions, influenced by systemic inefficiencies and societal skepticism (Yang, 2009; Yao 2009), leading to a persistent fracture in its transmission from differential order to a more generalized form (Xiong and Payne 2017). This dichotomy necessitates a critical reassessment of how trust is formed and operates across varied social spectrums, particularly within the rapidly modernizing transitional society (El Amine 2016).

Implications

Reflecting on the findings’ broader implications reveals their substantial influence on policy-making, clinical practice, and future research directions. These insights can profoundly enrich the discourse for policymakers, clinicians, and scholars, emphasizing the integration of family dynamics into mental health strategies as a potent means to alleviate depression.

From a policy perspective, initiatives should cultivate environments that bolster family bonds and community trust, which are essential for mitigating depression risks. Family support programs offering counseling and workshops can enhance intimacy and communication between parents and adult children, reinforcing trust within these vital relationships. Furthermore, addressing the ‘sandwich generation’s’ caregiving burdens through subsidized eldercare and flexible working arrangements can alleviate pressures, fostering deeper, trust-based familial connections. The findings highlight the mediating role of trust in parents and neighbors, underscoring the need for policies that not only strengthen family ties but also enhance community solidarity. Prioritizing these intimate and communal relationships over broader social trust can significantly impact depression mitigation efforts.

In clinical practice, integrating family dynamics into mental health care is essential. Mental health professionals should assess the depth of patients’ relationships with their parents during psychiatric evaluations, using these insights to inform treatment strategies that utilize familial bonds as therapeutic assets. Additionally, there’s a need to emphasize trust-building within immediate familial and community relationships, employing interventions tailored to these dynamics. Given the findings on the mediating role of trust in parents and neighbors, but not in strangers, local government officials, or physicians, targeted therapeutic strategies should focus on these key relationships to enhance treatment efficacy for depression.

This study, highlighting the mediating role of trust in parents and neighbors in the intimacy-depression nexus, invites further nuanced research. Investigating these dynamics across diverse cultures, where societal norms shape family interactions distinctly, is essential. Longitudinal studies could elucidate the evolution and long-term mental health impacts of these relationships. Additionally, exploring the interplay between intimacy with parents and factors like genetics could offer a comprehensive depression etiology. This multifaceted approach would deepen insights into family dynamics’ mental health effects and expand research on the intricate ties between interpersonal relationships and well-being.

Limitations and future prospects

One notable limitation of this study is the younger average age of the sample, primarily due to the exclusion of individuals whose parents are deceased and the greater propensity of younger participants to engage in longitudinal studies. This selection criterion aimed to focus the analysis on the relationship dynamics between living parents and their offspring. As a result, the findings primarily reflect the nuances of intimacy and its mental health implications within these extant parental relationships, which may not fully encapsulate the experiences of broader age demographics or scenarios involving deceased parents.

This limitation underscores the imperative for future research to investigate the complexities of intimacy with parents across a wider age spectrum, including older cohorts potentially affected by parental loss. Exploring the psychological ramifications of a parent’s absence, owing to death, on individuals’ mental health and their conceptualization of intimacy could unveil profound insights into the enduring influence of parental bonds, even in their physical absence.

Additionally, subsequent investigations would be fruitful if they scrutinized the dynamics of intimacy with parents within varied cultural and social milieus, discerning how societal conventions and values shape the formation and sustenance of these bonds and their consequent mental health effects. By broadening the research ambit to encompass these facets, future studies can deepen the comprehension of the relationship between intimacy with parents and depression throughout the human lifecycle.

Conclusions

Rooted in the principles of attachment theory, this study utilizes the 2018 and 2020 CFPS datasets to examine how intimacy with parents influences depression, with a particular emphasis on the mediating function of trust. The findings indicate that intimacy with parents significantly mitigates depression, with trust in parents and neighbors serving as crucial mediators. In contrast, trust in strangers, local government officials, and physicians did not demonstrate a significant mediating effect. These results highlight the critical role of robust familial and community bonds in addressing depression and stress the need for a nuanced understanding of trust in both policymaking and clinical interventions. This approach encourages the fostering of significant connections within families and communities, vital in navigating the complexities of a rapidly modernizing societal landscape.