Associations of recent stressful life events with anxiety symptoms among Chinese adolescents with a consideration of family functioning

ABSTRACT

Background: The association between stressful life events (SLEs) and adolescent anxiety symptoms has been extensively studied, but the specific impacts of different SLEs domains remain inconclusive. Moreover, limited research has examined the role of family functioning in these associations.

Objective: This study aimed to investigate the associations between various recent SLEs and adolescent anxiety symptoms and explore the role of family functioning.

Methods: Data were obtained from the second phase of the Longitudinal Study of Adolescents’ Mental and Behavioral Well-being Research in Guangzhou, China. A total of 10,985 students (51.9% boys; mean [SD] age, 15.3 [1.5] years) from forty middle schools participated in the study in 2022 and completed a self-report questionnaire assessing anxiety symptoms, SLEs, and family functioning using the Generalized Anxiety Disorder-7 (GAD-7), Adolescent Self-rating Life Events Checklist (ASLEC; including five subscales: interpersonal stress, academic stress, punishment-related stress, loss-related stress, and adaptation-related stress), and the adapted Chinese version of the Family Assessment Device (FAD), respectively. Linear mixed-effects models were performed and the moderation role of family functioning was also examined.

Results: The fully adjusted model revealed that a 1-SD increase in the overall ASLEC score was associated with higher levels of anxiety symptoms (β = 2.23, 95%CI: 2.15–2.32). Among various SLEs domains, the academic domain shows the most significant association (β = 2.25, 95%CI: 2.17–2.33). Family functioning exerted an independent protective influence on anxiety symptoms, with each 1-SD increase in FAD scores negatively associated with anxiety symptoms (β = −2.11, 95%CI: – 2.29 to – 1.93) in the adjusted model. Moreover, family functioning significantly buffered the impacts of overall SLEs and each domain, except for adaptation-related SLEs, on anxiety symptoms.

Conclusion: Higher recent SLEs levels were associated with increased anxiety symptoms among adolescents, with academic SLEs showing the greatest association. Positive family functioning had both direct and buffering influences on anxiety symptoms.

HIGHLIGHTS

• Higher levels of recent stressful life events may increase adolescents’ anxiety symptoms.

• Academic stressful life events show the greatest association with anxiety symptoms.

• Family functioning may be a promising intervention target for adolescent anxiety symptoms.

Antecedentes: La asociación entre los acontecimientos vitales estresantes (AVEs) y los síntomas de ansiedad en adolescentes se ha estudiado ampliamente, pero los impactos específicos de los diferentes dominios de los AVEs siguen sin ser concluyentes. Además, escasas investigaciones han examinado el papel del funcionamiento familiar en estas asociaciones.

Objetivo: Este estudio tuvo como objetivo investigar las asociaciones entre varios AVEs recientes y síntomas de ansiedad adolescente y explorar el papel del funcionamiento familiar.

Método: Los datos se obtuvieron de la segunda fase del Estudio Longitudinal de Investigación sobre el Bienestar Mental y Conductual de los Adolescentes en Guangzhou, China. Un total de 10.985 estudiantes (51,9% niños varones; edad media [DE], 15,3 [1,5] años) de cuarenta escuelas intermedias participaron en el estudio en 2022 y completaron un cuestionario de autoinforme que evaluaba los síntomas de ansiedad, el LES y el funcionamiento familiar utilizando el Trastorno de ansiedad generalizada-7 (GAD-7), Lista de verificación de acontecimientos vitales de autoevaluación del adolescente (ASLEC; que incluye cinco subescalas: estrés interpersonal, estrés académico, estrés relacionado con el castigo, estrés relacionado con la pérdida y estrés relacionado con la adaptación) y la versión china adaptada del Dispositivo de Evaluación Familiar (FAD), respectivamente. Se realizaron modelos lineales de efectos mixtos y también se examinó el papel moderador del funcionamiento familiar.

Resultados: El modelo completamente ajustado reveló que un aumento de 1 DE en la puntuación ASLEC general se asoció con niveles más altos de síntomas de ansiedad (β = 2,23, IC del 95%: 2,15 a 2,32). Entre varios dominios de AVEs, el dominio académico muestra la asociación más significativa (β = 2,25, IC95%: 2,17 a 2,33). El funcionamiento familiar ejerció una influencia protectora independiente sobre los síntomas de ansiedad, y cada aumento de 1 DE en las puntuaciones FAD se asoció negativamente con los síntomas de ansiedad (β = −2,11; IC del 95%: – 2,29 a -1,93) en el modelo ajustado. Además, el funcionamiento familiar amortiguó significativamente los impactos de los AVEs generales y de cada dominio, excepto los AVEs relacionados con la adaptación, sobre los síntomas de ansiedad.

Conclusión: Los niveles más altos de AVEs recientes se asociaron con un aumento de los síntomas de ansiedad entre los adolescentes, y los AVEs académicos mostraron la asociación más importante. El funcionamiento familiar positivo tuvo influencias tanto directas como amortiguadoras sobre los síntomas de ansiedad.

KEYWORDS:

• Adolescent
• stressful life event
• anxiety
• family functioning
• stress type

PALABRAS CLAVE:

• Adolescentes
• evento de vida estresante
• ansiedad
• funcionamiento familiar
• tipo de estrés

1. Introduction

Anxiety, one of the most common mental health problems among young people, imposes significant costs on individuals, families, and society (Piao et al., 2022; Yang et al., 2021). Approximately one in five adolescents worldwide suffer from elevated anxiety symptoms during the COVID-19 pandemic (Racine et al., 2021). Addressing the issue of anxiety symptoms in youth is crucial because adolescence represents a critical transitional period for physical maturation, psychological change, and social adaptation but also a sensitive window for the onset of multiple psychological problems (Ferschmann et al., 2022; Sisk & Gee, 2022). Childhood and adolescent anxiety symptoms are widely reported to be the precursor to full-blown anxiety disorder, depression, and somatisation symptoms (Ballester et al., 2022; Lee & Vaillancourt, 2020), highlighting the necessity of early detection and intervention. Given the high prevalence and serious adverse outcomes, there is no doubt that adolescent anxiety has been a major public health issue nowadays, and continued efforts in prevention and early intervention are warranted.

Anxiety issues involve a complex interplay between genetic predisposition and environmental factors (Wehry et al., 2015). The identification of modifiable risk factors has gained increasing attention due to the continuous imposition of new social and environmental threats on adolescent health in our rapidly changing society (de Figueiredo et al., 2021; Ferschmann et al., 2022). Stressful life events (SLEs) have been recognised as critical predictors of the development of psychological problems in adolescents (Asselmann & Beesdo-Baum, 2015; Sisk & Gee, 2022). While numerous studies have demonstrated the detrimental and enduring psychological effects of early life stress, recent research suggests that exposure to stressors during early childhood and adolescence can lead to distinct neurobiological phenotypic alterations, considering adolescence as another sensitive period of development (Cohodes et al., 2021; Zhu et al., 2023). Therefore, in addition to early life adversity, recent SLEs experienced during adolescence are also of concern. Both cross-sectional and longitudinal evidence consistently link a higher number of SLEs during adolescence to elevated levels of internalising problems, including anxiety symptoms (March-Llanes et al., 2017). Apart from the cumulative impact of SLEs on anxiety symptoms, there is increasing attention on the unique influence of certain types of SLEs. Previous studies have primarily focused on interpersonal SLEs and have shown that experiencing more of these may have a more significant impact on adolescents’ anxiety symptoms compared to non-interpersonal SLEs (Levin & Liu, 2021; Owens et al., 2019; Schneider et al., 2021). It is reasonable to prioritise interpersonal stress given that adolescence is a hypersensitive period for peer interaction and negative social stimuli (Orben et al., 2020). However, it is important to note that other types of SLEs, such as adaptation and academic stress, are also prevalent in China, where society rapidly evolves, and peer pressure is particularly pronounced (Jiang et al., 2022). Understanding the unique influence of specific types of SLEs may help optimise prevention and intervention efforts, although current reports on the specific impact of different types of SLEs have yielded mixed results (Casline et al., 2021; March-Llanes et al., 2017).

As there has been an increasing demand to incorporate family-focused prevention into public health practice, the importance of the family is gaining attention in the field of adolescent mental health (Hanson et al., 2019). The family plays a crucial role in adolescent development, serving as a significant source of positive social support, but it can also contribute to long-term psychological and behavioural issues (Bogels & Brechman-Toussaint, 2006; Drake & Ginsburg, 2012). Family functioning refers to the interactions among family members and the overall functioning of the family as a unit, representing the internal dynamics of a family (Holtom-Viesel & Allan, 2014). Research suggests that dynamic family functioning may have a greater impact on mental health outcomes than stable factors like family structure (Cheng et al., 2017). Previous studies have demonstrated a negative correlation between favourable family functioning and psychological problems in adolescents (Burnett et al., 2017; Guerrero-Munoz et al., 2021; Shao et al., 2020). A family with good functioning can create a supportive environment and enhance adolescents’ psychological resilience (Shao et al., 2022). Therefore, it is hypothesised that family functioning may act as a protective factor and mitigate anxiety symptoms triggered by SLEs. However, research examining the combined effects of SLEs and family functioning on anxiety symptoms is limited, and the existing findings are inconclusive (Scully et al., 2019). Therefore, the objectives of this study are twofold: to investigate the associations between SLEs and anxiety symptoms, and to examine the potential role of family functioning in these associations. Based on existing evidence, the hypotheses to be tested in this study are as follows: (1) recent SLEs would be positively associated with higher levels of anxiety symptoms, with potential variations across different types of SLEs; (2) better family functioning would be associated with lower levels of anxiety symptoms and may act as a buffer against the impacts of SLEs.

2. Material and methods

2.1. Study design and participants

Data for the current study were obtained from the second phase of the Longitudinal Study of Adolescents’ Mental and Behavioral Well-being Research in Guangzhou, China (Registration No. ChiCTR1900022032), conducted in June and September 2022. A multi-stage stratified cluster random sampling was employed, and the following procedures were implemented (Guo et al., 2021). In the first stage, 40 middle schools were selected from all 11 districts of Guangzhou, ensuring representative sampling across the city. The selection considered school distribution across districts, data collection convenience, and past cooperation. In the second stage, three classes were randomly chosen from each of the first and second grades, specifically grade 7 (12–13 years) and grade 8 (13–14 years) in selected junior high schools, and grade 10 (15–16 years) and grade 11 (16–17 years) in selected senior high schools. Students in grade 9 and grade 12 were excluded to minimise potential bias associated with the high stress levels related to entrance exams for further education. In the final stage, all students in the selected classes were invited to participate in this study. A self-report questionnaire was utilised to collect information. Ultimately, a total of 11,178 students from 240 classes were eligible to participate. Among these, 10,985 completed the questionnaire, providing complete information regarding the dependent variable and not simultaneously having missing data on all exposure variables, resulting in a response rate of 98.3%. The study procedures were carried out in accordance with the Declaration of Helsinki. Ethical approval for this study was granted by the Sun Yat-Sen University School of Public Health Institutional Review Board (L2021079). Written informed consent was obtained from each participant and one of their legal guardians, providing an explanation of the study’s objectives, procedures, benefits, and potential risks.

2.2. Measures

2.2.1. Anxiety symptoms

Anxiety symptoms were assessed using the Generalized Anxiety Disorder-7 (GAD-7) (Spitzer et al., 2006), which has been validated for use among Chinese adolescents and has demonstrated good psychometric properties (Ip et al., 2022). The GAD-7 consists of 7 items, each rated on a 4-point Likert scale ranging from 0 (never) to 3 (nearly every day), with a total score range of 0–21. Participants with higher scores were classified as having more severe anxiety symptoms. Additionally, we applied a validated cut-off value of a GAD-7 score ≥ 7 to indicate a probable anxiety state (Ip et al., 2022).

2.2.2. Stressful life events

Stressful life events were assessed using the Adolescent Self-rating Life Events Checklist (ASLEC), originally developed by Liu et al. and validated in Chinese adolescents (Liu & Tein, 2005). The ASLEC consists of 27 items that evaluate the occurrence and intensity of SLEs over the past year. Among these items, 26 represent specific SLEs and can be categorised into five domains: ‘interpersonal stress’, ‘academic stress’, ‘punishment-related stress’, ‘loss-related stress’ and ‘adaptation-related stress’ (Xin & Yao, 2015). The ASLEC items were rated on a 6-point scale, with participants asked to rate the impact intensity of each SLE, ranging from ‘1 = no impact’ to ‘5 = extremely severe’. If an event did not occur, it was rated as ‘0’ (Xin & Yao, 2015). Higher scores indicate a greater intensity of SLEs. In this study, the score of each item of the scale (from ‘0 = did not occur’ to ‘5 = extremely severe’) was also used to represent the individual impact intensity of each specific SLE, and the presence of each SLE was identified as either absent (‘did not happen’) or present (‘mild impact’ to ‘extremely severe’). Additionally, we calculated the number of SLEs experienced (the sum of 26 items after classifying each item as absent or present, ranging from 0 = no SLEs occurred to 26 = all 26 SLEs occurred) to represent the cumulative amount of SLEs regardless of their impacts.

2.2.3. Family functioning

Family functioning was evaluated using the adapted Chinese version of the Family Assessment Device (FAD). The FAD was originally developed based on the McMaster Model of Family Functioning and later modified by Li et al., considering the cultural context in China. This adapted version has been validated in the Chinese population (Epstein et al., 1983; Li et al., 2013). This FAD comprises 30 items that are rated on a 4-point Likert scale. Participants were asked to indicate their perception of their families, with response options ranging from 1 (totally disagree) to 4 (totally agree) (Li et al., 2013). Higher FAD scores indicate better family functioning.

2.2.4. Other variables

We created a directed acyclic graph (DAG) to visually represent the potential confounding relationships (eFigure 1) and determine the necessary adjustment sets of covariates for the multivariable analyses (Krieger & Davey Smith, 2016). The DAG revealed the potential covariates encompassed sex, grade, highest parental education level (the highest education level attained by any resident parent) (Zablotsky et al., 2022), perceived household socioeconomic status (SES) (Quon & McGrath, 2014), and living arrangements at home (Perales et al., 2017).

2.3. Statistical analysis

Descriptive analyses were initially performed, and the means and standard deviations (SDs) were calculated for continuous variables, while the frequency and percentages were calculated for categorical variables. A comparison of participant characteristics based on anxiety symptoms status (defined as a probable anxiety state with GAD-7 ≥ 7) was conducted using t-tests or Mann–Whitney U tests for continuous variables or Chi-square tests for categorical variables. Linear mixed-effects models, accounting for the multilevel nature of the data, were employed to examine the associations between SLEs, family functioning, and anxiety symptoms, with the school unit treated as a random effect. The dependent variable in these models was the GAD-7 scores, with β coefficients and corresponding 95% CIs calculated, where a β coefficient > 0 indicated a positive association (Schneider et al., 2010). Univariable models were initially run, entering the overall SLEs score, scores of each SLEs domain, and the FAD score separately into the model. Potential covariates selected according to the DAG were then adjusted in the multivariable models. Due to the different dimensions of the scales used in the study, the total ASLEC and FAD raw scores, and each subscale of ASLEC scores, were standardised using z-scores (mean = 0, SD = 1) in the above models. Estimates for the unadjusted and adjusted linear mixed-effects models were interpreted as the difference in anxiety symptom scores associated with a 1-SD increase in total ASLEC or FAD scores, or each subscale of ASLEC scores (Johansson et al., 2023). Furthermore, multivariable models were run for each specific SLE (the score of each item in ASLEC, from 0 = did not occur to 5 = extremely severe) to explore their individual associations as secondary analyses. In this secondary analysis, the occurrence rate for each SLE was calculated to identify which specific SLEs were more prevalent, and the impacts of each SLE were examined by categorising each item in ASLEC as ‘0 = did not happen (absence of SLE)’ and ‘1 = no impact to extremely severe (presence of SLE)’. Additionally, the association of the number of SLEs (the sum of 26 items after classifying each item as absent or present, ranging from 0 = no SLEs occurred to 26 = all 26 SLEs occurred) experienced during the past year with anxiety symptom scores was investigated. To further explore the role of family functioning in the association between each SLEs domain and anxiety symptoms, an interaction term of FAD z-score and SLEs z-score was included in the primary multivariable models. To test the robustness of the findings, sensitivity analyses were conducted. The first sensitivity analysis utilised an alternative method to calculate the ASLEC scale. In this method, a score of 0 was assigned to ‘did not happen’ or ‘no impact’, while a score of 1–4 was assigned to ‘minor impact’ to ‘extremely severe’ (Hou et al., 2021). The second sensitivity analysis involved generating 5 imputed datasets using the multiple imputation by chained equations (MICE) method, followed by replicating the main analyses to examine the impact of missing data (White et al., 2011). All statistical analyses were conducted using Stata, version 17 (StataCorp), with a two-sided P value < .05 considered statistically significant. Bonferroni correction was applied to account for multiple testing in the association models, with a P-value < .0015 (α .05/33 exposures) considered statistically significant after correction for multiple testing (Curtin & Schulz, 1998). The correction of multiple testing was also applied in the interaction analyses, with an adjusted α set at 0.0083 for the 6 models (6 SLEs exposures’ interactions with family functioning).

3. Results

Table 1 presents the characteristics of the 10,985 eligible participants. Among them, 5698 were boys (51.9%), and the mean age was 15.3 (SD: 1.5) years. Significant differences were observed between those with GAD-7 scores equal to or greater than 7 and those with scores less than 7 in terms of grade level, sex, living arrangements at home, and perceived household SES. Participants with GAD-7 scores equal to or greater than 7 had significantly higher scores on the overall ASLEC scores as well as each subscale, compared to those with GAD-7 scores less than 7 (all P < .001). Moreover, students with a probable anxiety state had lower FAD scores than those without a probable anxiety state (GAD-7 ≥ 7 group: 84.3 [SD = 13.3] vs. GAD-7 < 7 group: 94.0 [SD = 13.3], P < .001).

Table 1. Demographic characteristics of participants, n (%).

Variables	Total, N = 10785	GAD-7 score < 7^a, N = 8338	GAD-7 score ≥ 7^a, N = 2647	P-value^c
Age, mean (SD), year	15.3 (1.5)	15.3 (1.5)	15.4 (1.5)	<.001
Grade
7th	1951 (17.8)	1539 (18.5)	412 (15.6)	<.001
8th	1827 (16.6)	1459 (17.5)	368 (13.9)
10th	4024 (36.6)	3007 (36.1)	1017 (38.4)
11th	3183 (29.0)	2333 (28.0)	850 (32.1)
Sex
Boy	5698 (51.9)	4575 (54.9)	1123 (42.4)	<.001
Girl	5287 (48.1)	3763 (45.1)	1524 (57.6)
Living arrangements at home
Living with both parents	9061 (82.5)	6937 (83.5)	2124 (80.4)	.001
Living with a single parent	1139 (10.4)	809 (9.7)	330 (12.5)
Others	755 (6.9)	567 (6.8)	188 (7.1)
Missing value	30 (0.3)
Highest parental education level
Primary or below	195 (1.8)	148 (1.9)	47 (1.9)	.740
Lower secondary	2287 (20.8)	1712 (22.1)	575 (23.1)
Senior secondary	2768 (25.2)	2094 (27.0)	674 (27.1)
Tertiary or above	4989 (45.4)	3795 (49.0)	1194 (48.0)
Missing value	746 (6.8)
Perceived household SES
Above average	3980 (36.2)	3229 (39.9)	751 (29.3)	<.001
Average	5981 (54.5)	4411 (54.5)	1570 (61.3)
Below average	694 (6.3)	452 (5.6)	242 (9.4)
Missing value	330 (3.0)
Interpersonal stress, mean (SD)^b	5.0 (4.0)	4.1 (3.5)	7.9 (4.2)	<.001
Academic stress, mean (SD)^b	6.1 (4.2)	5.1 (3.6)	9.3 (4.2)	<.001
Punishment-related stress, mean (SD)^b	2.9 (4.3)	2.3 (3.6)	5.0 (5.6)	<.001
Loss-related stress, mean (SD)^b	3.3 (4.0)	2.6 (3.4)	5.4 (4.9)	<.001
Adaptation-related stress, mean (SD)^b	3.3 (3.3)	2.5 (2.7)	5.6 (3.8)	<.001
Overall ASLEC scores, mean (SD)^b	20.5 (15.6)	16.5 (12.9)	33.2 (16.8)	<.001
FAD scores, mean (SD)^b	91.7 (13.9)	94.0 (13.3)	84.3 (13.3)	<.001
GAD-7 scores, mean (SD)	4.1 (4.4)	2.1 (2.1)	10.3 (4.1)	<.001

Notes. ASLEC: Adolescent Self-rating Life Events Checklist; FAD: Family Assessment Device; GAD-7: Generalized Anxiety Disorder scale-7 item; SES: socioeconomic status; SD: standard deviation.

^a A GAD-7 score of less than 7 was considered probable to be free of anxiety symptoms, while a GAD-7 score equal to or above 7 was considered to be of potential anxiety state.

^b ASLEC and FAD scores were presented as raw scores.

^c Chi-square tests were used to test for differences in the distribution of categorical variables between males and females, and t-tests or Mann-Whitney U tests were used to test for differences in the means of continuous variables. A P-value of less than .05 was considered statistically significant.

As presented in Table 2, both the unadjusted and adjusted models demonstrated a positive association between overall SLEs and anxiety symptoms across all domains of SLE. Moreover, a 1-SD increase in family functioning scores was found to be negatively associated with anxiety symptoms, and this association remained significant even after adjusting for covariates in model 2 (β = −2.11, 95%CI: – 2.29 to – 1.93). In the fully adjusted model 3, which controlled for grade, sex, living arrangement at home, parental education level, perceived household SES, and family functioning, a 1-SD increase in the overall intensity of SLEs was associated with higher GAD-7 scores (β = 2.23, 95%CI: 2.15–2.32). Academic SLEs exhibited the strongest association with GAD-7 scores (β = 2.25, 95%CI: 2.17–2.33). Furthermore, when family functioning was included as a covariate in the multivariable models, the strength of the associations between SLEs and anxiety symptoms was attenuated.

Table 2. Associations of stressful life events with anxiety symptoms.

Variables^a	Model 1		Model 2		Model 3
	β (95% CI)^b	P^c	β (95% CI)^b	P^c	β (95% CI)^b	P^c
Interpersonal SLEs (1-SD increase)	2.13 (2.05–2.20)	<.0001	2.07 (1.99–2.15)	<.0001	1.93 (1.85–2.01)	<.0001
Academic SLEs (1-SD increase)	2.42 (2.35–2.49)	<.0001	2.36 (2.29–2.44)	<.0001	2.25 (2.17–2.33)	<.0001
Punishment-related SLEs (1-SD increase)	1.42 (1.34–1.50)	<.0001	1.43 (1.35–1.52)	<.0001	1.25 (1.16–1.33)	<.0001
Adaptation-related SLEs (1-SD increase)	2.07 (2.00–2.15)	<.0001	2.00 (1.92–2.08)	<.0001	1.83 (1.74–1.92)	<.0001
Loss-related SLEs (1-SD increase)	1.47 (1.39–1.55)	<.0001	1.43 (1.35–1.52)	<.0001	1.25 (1.16–1.34)	<.0001
Overall ASLEC scores (1-SD increase)	2.39 (2.32–2.46)	<.0001	2.36 (2.28–2.44)	<.0001	2.23 (2.15–2.32)	<.0001
Family functioning (1-SD increase)	−2.16 (−2.00 to – 2.32)	<.0001	−2.11 (−2.29 to – 1.39)	<.0001	NA	NA

Notes. SLEs: stressful life events; SD: standard deviations; CI: confidence interval; NA: not applicable.

Model 1 was the unadjusted model.

Model 2 was adjusted for grade, sex, living arrangement, perceived family socioeconomic status, and highest parental education level.

Model 3 was adjusted for the variables in Model 2 plus family functioning.

^a ASLEC and FAD scores were standardised (mean = 0 and SD = 1);

^b β coefficient and its 95% CI were reported as unstandardised coefficients.

^c Bonferroni correction was used for multiple testing. P-values of less than .0015 were considered statistically significant.

Tables 3 and 4 display the associations of impact intensities and presences of each specific SLE with GAD-7 scores, respectively. Among the 26 specific SLEs investigated in this study, ‘failure in an exam’ and ‘heavy study load’ were the two most prominently associated with anxiety symptoms after controlling for covariates, whether using impact intensity or presence as the indicator. The three most frequently reported SLEs were ‘failure in an exam’(86.7%), ‘heavy study load’(74.3%), and ‘misunderstood or wrongly blamed by peers’(70.4%). Additionally, experiencing more overall SLEs during the past year was still positively associated with anxiety symptom scores even after controlling for covariates and family functioning (β = 0.23, 95%CI: 0.21–0.24) (Table 4).

Table 3. Associations of the impact intensities of each specific SLE with anxiety symptoms.

Stressful life events (one-score increase)^a	Model 1		Model 2
	β (95% CI)^b	P-value^c	β (95% CI)^b	P-value^c
Misunderstood/wrongly blamed by peers	1.40 (1.33–1.47)	<.0001	1.28 (1.22–1.35)	<.0001
Being discriminated against	1.23 (1.17–1.30)	<.0001	1.11 (1.04–1.17)	<.0001
Failure in an exam	1.50 (1.43–1.56)	<.0001	1.41 (1.34–1.47)	<.0001
Conflict with classmate(s)/friend(s)	1.24 (1.18–1.31)	<.0001	1.13 (1.07–1.20)	<.0001
Significant changes in lifestyle patterns	1.44 (1.37–1.51)	<.0001	1.30 (1.23–1.37)	<.0001
Unsatisfied with school	1.28 (1.21–1.35)	<.0001	1.16 (1.09–1.23)	<.0001
Trouble in a romantic relationship	0.90 (0.80–0.99)	<.0001	0.76 (0.66–0.86)	<.0001
Live apart from parents for a long time	0.79 (0.68–0.89)	<.0001	0.68 (0.58–0.78)	<.0001
Heavy study load	1.51 (1.45–1.57)	<.0001	1.43 (1.37–1.49)	<.0001
Conflict with teacher(s)	1.21 (1.11–1.30)	<.0001	1.02 (0.92–1.12)	<.0001
Serious illness/injury	0.70 (0.56–0.84)	<.0001	0.57 (0.43–0.72)	<.0001
Serious illness/injury of a family member/friend	0.63 (0.54–0.72)	<.0001	0.54 (0.45–0.64)	<.0001
Death of a family member/friend	0.44 (0.36–0.52)	<.0001	0.38 (0.30–0.46)	<.0001
Stolen or missing items	0.98 (0.90–1.06)	<.0001	0.86 (0.78–0.94)	<.0001
Disgraced in public	1.31 (1.24–1.37)	<.0001	1.18 (1.12–1.25)	<.0001
Family financial hardship	1.09 (1.00–1.18)	<.0001	0.93 (0.83–1.02)	<.0001
Within-family conflict	1.13 (1.07–1.20)	<.0001	0.97 (0.90–1.04)	<.0001
Not chosen as expected (e.g. honour roll)	1.09 (1.00–1.17)	<.0001	0.98 (0.89–1.06)	<.0001
Criticized/punished in school	0.99 (0.92–1.07)	<.0001	0.88 (0.80–0.96)	<.0001
Transferred to a new school/suspended	0.70 (0.58–0.81)	<.0001	0.56 (0.45–0.68)	<.0001
Penalized	0.72 (0.59–0.85)	<.0001	0.57 (0.44–0.70)	<.0001
Pressure to progress to higher education	1.11 (1.05–1.17)	<.0001	1.05 (0.99–1.11)	<.0001
Physical fights with peers	0.94 (0.82–1.07)	<.0001	0.78 (0.65–0.90)	<.0001
Beaten or scolded by parents	1.16 (1.09–1.23)	<.0001	0.98 (0.91–1.06)	<.0001
Expected/pushed too much by parents	1.27 (1.21–1.33)	<.0001	1.15 (1.09–1.22)	<.0001
Unexpected shock (e.g. in an accident)	1.20 (1.10–1.30)	<.0001	1.05 (0.95–1.15)	<.0001

Notes. SLEs: stressful life events; NA: not applicable.

Model 1 was a multivariable model, adjusting for grade, sex, living arrangements at home, perceived family socioeconomic status, and highest parental education level.

Model 2 was adjusted for the variables in Model 1 plus family functioning.

^a The raw scores of each ASLEC item were used in the analyses.

^b β coefficient and its 95% CI were reported as unstandardised coefficients.

^c Bonferroni correction was used for multiple testing. P-values of less than .0015 were considered statistically significant.

Table 4. Associations of the presence of specific SLEs with anxiety symptoms.

Stressful life events (ref = absence of SLE)^a	Occurrence rate, %	Model 1		Model 2
		β (95% CI)^c	P-value^d	β (95% CI)^c	P-value^d
Cumulative SLEs (Each additional SLE occurs)^b	NA	0.29 (0.28–0.30)	<.0001	0.23 (0.21–0.24)	<.0001
Misunderstood/wrongly blamed by peers	7843 (70.5)	2.33 (2.15–2.52)	<.0001	1.77 (1.58–1.95)	<.0001
Being discriminated against	4885 (43.9)	2.38 (2.21–2.55)	<.0001	1.77 (1.59–1.94)	<.0001
Failure in an exam	9652 (86.7)	2.54 (2.29–2.80)	<.0001	2.04 (1.79–2.29)	<.0001
Conflict with classmate(s)/friend(s)	7581 (68.3)	2.12 (1.94–2.30)	<.0001	1.61 (1.43–1.79)	<.0001
Significant changes in lifestyle patterns	6565 (59.0)	2.50 (2.33–2.67)	<.0001	1.93 (1.75–2.10)	<.0001
Unsatisfied with school	5408 (48.7)	2.55 (2.38–2.72)	<.0001	1.94 (1.77–2.12)	<.0001
Trouble in a romantic relationship	1634 (14.7)	1.82 (1.58–2.06)	<.0001	1.21 (0.97–1.45)	<.0001
Live apart from parents for a long time	2503 (22.5)	1.41 (1.19–1.62)	<.0001	0.90 (0.69–1.11)	<.0001
Heavy study load	8258 (74.3)	2.91 (2.72–3.11)	<.0001	2.44 (2.25–2.64)	<.0001
Conflict with teacher(s)	2984 (26.9)	2.05 (1.86–2.24)	<.0001	1.39 (1.20–1.58)	<.0001
Serious illness/injury	830 (7.4)	1.43 (1.10–1.76)	<.0001	0.79 (0.47–1.12)	<.0001
Serious illness/injury of a family member/friend	1689 (15.2)	1.28 (1.05–1.52)	<.0001	0.79 (0.56–1.03)	<.0001
Death of a family member/friend	2089 (18.8)	0.89 (0.67–1.10)	<.0001	0.52 (0.30–0.73)	<.0001
Stolen or missing items	4598 (41.3)	1.68 (1.50–1.85)	<.0001	1.26 (1.09–1.43)	<.0001
Disgraced in public	6569 (59.0)	2.36 (2.19–2.53)	<.0001	1.81 (1.64–1.99)	<.0001
Family financial hardship	3253 (29.3)	2.10 (1.89–2.30)	<.0001	1.43 (1.22–1.63)	<.0001
Within-family conflict	5006 (45.2)	2.22 (2.05–2.39)	<.0001	1.37 (1.19–1.55)	<.0001
Not chosen as expected (e.g. honour roll)	4405 (39.5)	1.54 (1.36–1.71)	<.0001	1.11 (0.94–1.28)	<.0001
Criticized/punished in school	3612 (32.5)	1.64 (1.45–1.82)	<.0001	1.16 (0.98–1.35)	<.0001
Transferred to a new school/suspended	945 (8.5)	1.39 (1.08–1.70)	<.0001	0.74 (0.44–1.05)	<.0001
Penalized	949 (8.5)	1.24 (0.93–1.55)	<.0001	0.65 (0.34–0.96)	<.0001
Pressure to progress to higher education	5691 (51.2)	2.08 (1.91–2.25)	<.0001	1.72 (1.55–1.89)	<.0001
Physical fights with peers	1382 (12.4)	1.75 (1.48–2.01)	<.0001	1.11 (0.85–1.38)	<.0001
Beaten or scolded by parents	3383 (30.5)	2.21 (2.03–2.39)	<.0001	1.37 (1.18–1.57)	<.0001
Expected/pushed too much by parents	5228 (47.1)	2.45 (2.27–2.62)	<.0001	1.76 (1.59–1.93)	<.0001
Unexpected shock (e.g. in an accident)	2016 (18.1)	2.25 (2.03–2.47)	<.0001	1.69 (1.47–1.91)	<.0001

Notes. SLEs: stressful life events; NA: not applicable.

Model 1 was a multivariable model, adjusting for grade, sex, living arrangements at home, perceived family socioeconomic status, and highest parental education level.

Model 2 was adjusted for the variables in Model 1 plus family functioning.

^a We categorised each item of ASLEC as 0 (did not happen, indicating the absence of SLE) and 1 (no impact to extremely severe, indicating the presence of SLE), and the absences of SLE (coded as 0) were used as references in the models.

^b The cumulative SLEs indicate the number of SLEs experienced. To be more specific, after categorising each item as 0 (did not happen) and 1 (no impact to extremely severe), the sum score of the 26 items was used (ranging from 0 to 26).

^c β coefficient and its 95% CI were reported as unstandardised coefficients.

^d Bonferroni correction was used for multiple testing. P-values of less than .0015 were considered statistically significant.

Table 5 presents the results of the interaction terms between the domains of SLEs and family functioning. Except for adaptation-related stress (P-value = .071), all other interaction terms were found to be significant (all P-values for the interaction terms < .0083), with all the β coefficients for the interaction items being less than 0.

Table 5. The interactions between stressful life events and family functioning.

Interaction terms^a	β (95% CI)^b	P-value for interaction^c
Interpersonal SLEs × Family functioning	−0.25 (−0.33 to – 0.18)	<.001
Academic SLEs × Family functioning	−0.26 (−0.33 to – 0.19)	<.001
Punishment-related SLEs × Family functioning	−0.17 (−0.25 to – 0.09)	<.001
Adaptation-related SLEs × Family functioning	−0.07 (−0.15 to 0.01)	.071
Loss-related SLEs × Family functioning	−0.20 (−0.28 to – 0.11)	.001
Overall SLEs × Family functioning	−0.17 (−0.25 to – 0.10)	<.001

Notes. SLEs: stressful life events; CI: confidence interval.

All models were adjusted for grade, sex, living arrangements, perceived family socioeconomic status, and highest parental education level

^a ASLEC and FAD scores were standardised (mean = 0 and SD = 1).

^b β coefficient and its 95% CI were reported as unstandardised coefficients.

^c Bonferroni correction was used for multiple testing. P-values of less than .0083 were considered statistically significant.

Sensitivity analyses using another ASLEC calculation method yielded similar results to the primary analyses, except the interaction between overall SLEs and family functioning was insignificant after correction of multiple testing (P-value = 0.046 > .0083). Additionally, sensitivity analyses after imputing missing covariates showed robust results. Details were shown in eTables 1–4 in the supplementary materials.

4. Discussion

In this study of Chinese adolescents, both the total SLE score and all the specific SLE domains examined were significantly associated with higher levels of anxiety symptoms. Notably, the academic domain exhibited the strongest associations. Additionally, we observed that better family functioning was negatively associated with anxiety symptoms and appeared to mitigate the impact of SLEs on anxiety symptoms.

Our findings are consistent with numerous previous studies that have demonstrated the associations between SLEs and anxiety problems in adolescents (March-Llanes et al., 2017; Steeger et al., 2017). SLEs can potentially increase anxiety symptoms through various physiological and psychological mechanisms (McLaughlin & Hatzenbuehler, 2009; Zorn et al., 2017). The hypothalamic – pituitary – adrenal (HPA) axis, a major stress response system in the body, is among the most prevalent mechanisms in anxiety research (Zorn et al., 2017). When exposed to SLEs that exceed the regulation capacity of the HPA axis, the stress response system can become disrupted, leading to either blunted or heightened cortisol responses. This disruption may interfere with emotional regulation and increase the risk of anxiety problems (Zorn et al., 2017). Additionally, previous evidence has also identified psychological mechanisms such as emotional dysregulation, rumination, and maladaptive coping that link SLEs and adolescent mental health problems (McLaughlin & Hatzenbuehler, 2009; Meng et al., 2011; Michl et al., 2013). SLEs may disrupt the adaptive regulation of emotions, increase engagement in rumination or maladaptive coping, and thereby increase the risk of anxiety problems (McLaughlin & Hatzenbuehler, 2009; Meng et al., 2011; Michl et al., 2013). While there is extensive evidence linking early life stress, such as childhood trauma and traumatic life events to HPA axis dysfunction and mental disorders, recent non-traumatic SLEs experienced during puberty can also heighten the risk of anxiety and other mental health problems. This is because adolescence represents another critical developmental window during which the HPA axis exhibits increased plasticity, thereby heightening sensitivity to stress (Marques-Feixa et al., 2023; Sisk & Gee, 2022). The recent SLEs investigated in our study mainly encompass common non-traumatic events, such as interpersonal conflicts, family-related problems, academic problems, and adaptation-related problems. These events may occur more frequently than more severe forms of SLEs. Our findings are consistent with previous studies suggesting that, in addition to traumatic experiences, exposure to a wide variety of stressors during puberty can also increase the risk of internalising problems induced by SLEs (Jenness et al., 2019; Steeger et al., 2017; Willard et al., 2016). For example, one study demonstrated that higher levels of common family-related SLEs, such as moving or changing residence, were associated with greater internalising problems in adolescents, including anxiety symptoms. The impact of these SLEs was found to be moderated by cortisol reactivity levels (Steeger et al., 2017). Another study examined the differential impact of potentially traumatic events and other common SLEs (e.g. peer or school problems) on children’s psychological functioning. The findings indicated that the relationship between cumulative SLEs and psychological distress was primarily driven by common SLEs, even among those with a history of illness (Willard et al., 2016). Further research is needed to explore the implication of recent SLEs and other non-traumatic common SLEs on adolescent psychological health in order to better understand the complex relationships involved.

While the global measure of SLEs level (e.g. the aggregated number or intensity of SLEs) can be viewed as a general risk factor for a subsequent broad range of mental health problems, distinguishing between different types of SLEs may offer a more intuitive understanding of the link between SLEs and specific mental health problems. This distinction can provide a basis for decision-makers to optimise intervention (March-Llanes et al., 2017). Prior evidence has suggested that different types of early life stress may have differential effects on an individual’s neurobiological development through distinct pathways, resulting in unique psychological outcomes (Cohodes et al., 2021; Sisk & Gee, 2022). Adolescence represents another important transitional and developmental stage. The common stressors experienced during adolescence can be quite different from those in childhood and may have distinct and long-lasting impacts on neurological development (Sisk & Gee, 2022). In our study, the most frequently reported SLEs in the past year included ‘failure in an exam’, ‘heavy study load’, and ‘misunderstood or wrongly blamed by peers’, suggesting that academic and interpersonal problems were major concerns for the adolescents in our sample. An unexpected finding of this study is that among the five domains of SLEs examined, the academic domain demonstrates the strongest association with anxiety symptoms, whereas previous research on adolescent mental health has emphasised interpersonal stress, such as peer victimisation (Quinlan et al., 2020). Although our study did not include third graders who experience greater academic pressure, the association between overall SLEs and anxiety symptoms appears to be primarily driven by academic SLEs. These findings may be attributed to the constant academic stress adolescents face from parents, teachers, and society throughout puberty in China, where academic excellence is strongly emphasised (Shek & Siu, 2019). Some studies have reported that interpersonal SLEs are more strongly associated with higher anxiety symptoms than achievement-oriented SLEs or other non-interpersonal SLEs (Levin & Liu, 2021; Zou et al., 2018). For example, a longitudinal study conducted among children aged 6–12 found that interpersonal stress, rather than non-interpersonal stress, predicted greater anxiety and depression symptoms (Levin & Liu, 2021). Another study on Chinese college students also found that interpersonal and adaptation-related SLEs were more strongly associated with anxiety symptoms (Zou et al., 2018). These discrepancies in findings suggest that the major concerns of adolescents and the links between SLEs and anxiety symptoms may vary among different populations and cultural contexts. Despite the significant importance of interpersonal relationships in adolescent development, it may not be sufficient to focus solely on interpersonal SLEs. The influence of academic factors may also be a crucial aspect that needs to be considered in research on adolescent anxiety, especially in China or other regions where academic achievements are strongly emphasised.

According to the social support models proposed by Cohen and Wills, good social support can directly or indirectly mitigate the negative impacts of stressful events (Cohen & Wills, 1985). The influence of social support may vary depending on whether it focuses on structural aspects (such as the existence or density of social networks) or functional aspects (perceived supports that address the needs arising from stressful events) (Cohen & Wills, 1985). In this study, we expanded beyond the structural family factors, such as family composition, and explored the potential protective role of family functioning. Family functioning can be considered as functional support provided by the family environment. Our finding revealed that family functioning independently had a protective influence on adolescent anxiety symptoms, which is consistent with numerous previous findings indicating a negative association between positive family functioning and adolescent psychological problems (Burnett et al., 2017; Guerrero-Munoz et al., 2021; Song et al., 2019). It is possible that better family functioning, characterised by active communication, positive affective involvement, and effective problem-solving abilities, enhances adolescents’ psychological resilience and provides adequate resources for addressing SLEs (Shao et al., 2022). Furthermore, we observed that family functioning also buffered the impacts of most domains of SLEs, except for adaptation-related events. Similarly, Manczak et al. found that a supportive family environment could interact with disruptive life events and protect at-risk individuals from depressive symptoms (Manczak et al., 2018). However, a longitudinal study conducted in the United States by Sheidow et al. did not find a buffering effect of stress exposure on subsequent internalising outcomes (Sheidow et al., 2014). These inconsistent findings may be partially explained by cultural context differences. In Western countries, families often prioritise individual autonomy and independence, whereas in China or other regions influenced by collectivism and Confucianism, family members tend to be interdependent, and families revolve around the needs of children (Greenberger et al., 2000). Consequently, Chinese parents may be more involved when their children face life events. Our findings support both the direct and buffering effects of family functioning, underscoring the importance of cultivating a positive family environment and fostering strong relationships among family members. However, existing research is limited, and further studies are needed to examine the specific beneficial components of family functioning.

There are several limitations in the current study. First, the cross-sectional nature of the data restricts our ability to draw causal inferences. Anxious students may perceive their SLEs as more severe and rate their family functioning poorly, thus leading to the strong associations observed. However, our results indicated that an increase in the number of SLEs experienced, regardless of their intensity, was still positively associated with anxiety symptoms, suggesting some reliability in our conclusion. Additionally, this study consider the combined influences of both SLEs and family functioning, providing preliminary evidence for their associations with anxiety symptoms among adolescents and highlighting the protective role of family functioning. Second, although self-report questionnaires are widely accepted in related studies, reliance on such data may introduce recall bias. Third, although the stressful life event checklist employed in this study is widely used among the Chinese adolescent population, it may not encompass all potential SLEs that participants may have experienced. Future studies should aim to incorporate a more comprehensive range of stressors, including different types and chronologies. Fourth, early life stress was not measured in this study, despite some evidence indicating that adolescents with early life stress may be more vulnerable to recent SLEs through dysregulated HPA-axis function or other mechanisms (Stroud, 2020). We would like to collect information on early life stress and account for its influence in future studies.

5. Conclusions

Although the general link between stress and anxiety symptoms in adolescents has been extensively studied, there is still uncertainty regarding the impacts of recent SLEs and the specific influences of certain SLEs domains. Our study not only replicated most of the previous findings but also revealed that, in addition to interpersonal problems, academic SLEs emerged as another significant factor contributing to the association between overall SLEs and anxiety symptoms. The issue of academic stress among Chinese adolescents remains a pressing concern that requires prompt attention. Furthermore, our study expanded upon previous research by examining the role of family functioning and identified both direct and buffering effects of family functioning on the association between SLEs and anxiety symptoms in adolescents. These findings contribute to the existing literature on the protective influence of a supportive family environment. Identifying the key beneficial components of family functioning may inform targeted intervention strategies and should be the focus of further research.

Ethical approval

The study procedures were carried out in accordance with the Declaration of Helsinki. Ethical approval for this study was granted by the Sun Yat-Sen University School of Public Health Institutional Review Board (L2021079).

Acknowledgments

We wish to give particular thanks to all participating schools and students who have made the study possible.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability

Derived data supporting the findings of this study are available from the corresponding author on request.

Additional information

Funding

This work was supported by the Natural Science Foundation of Guangdong Province (grant number 2022A1515012333). The funder had no role in the design, analysis, write-up, or decision to submit for publication