2. Materials and Methods
2.1. Study Design, Setting, and Participants
The empirical psychometric validation—both descriptive and exploratory—study was conducted from April to May 2023 and was organized by the School of Pedagogical and Technological Education (ASPETE), a Greek university specializing in training secondary school teachers, in collaboration with the University of West Attica and the UNESCO Chair on Adolescent Health Care. The study was approved by the ethics and conduct committee of ASPETE (Protocol no: 23-4/4/23).
The initial study sample comprised 170 secondary school students from various regions of Greece. To be eligible for participation, students had to be enrolled in a Greek lyceum (upper secondary school for students aged 15–18) in either the first, second, or third year and possess the ability to read, write, and understand Greek. Students who did not attend a Greek lyceum were excluded from the study.
Participants were recruited through an open invitation issued by the study organizers to parents of upper secondary students in Greece via parents’ associations and the Hellenic Federation of the Teachers of Tutoring Centers (OΕΦΕ). The online invitation outlined the study’s objectives and described the measures taken to ensure participant anonymity. Parents who consented to their child’s voluntary participation were provided with a link to the study questionnaire. Their children would be able to complete the questionnaire at home and download stress management instructions and techniques for teenagers upon completion. On the opening page, the students were informed about the organizers and the scope of the study, and the completion of the questionnaire would take approximately 15 min.
2.2. Measures
The study questionnaire, besides questions regarding demographic data (sex, age, region, etc.), school data (grade, general or vocational lyceum, general or special education, etc.), socioeconomic data (perceived family’s socioeconomic status, parents’ level of studies, parents’ profession, etc.), and data concerning daily habits (following routines, having breakfast, type of diet, etc.), included the 10-item Perceived Stress Scale (PSS-10), as well as the Adolescent Stress Questionnaire, the Greek version of which had already been determined to have sound psychometric abilities (
Darviri et al. 2014).
The 10-item version of the Perceived Stress Scale (PSS-10) (
Cohen 1988) is a self-report tool originally developed in a 14-item form (
Cohen et al. 1983) and is designed to measure the degree to which situations of the latest month in one’s life are appraised as stressful. It consists of 10 items rated on a 5-point Likert-type scale, with answers ranging from 0 = never to 4 = very often. Higher scores indicate greater levels of stress. The two-factor structure of the PSS-10 shows one factor that is formed by the negative wording of items (non-reverse-worded scoring) and a second one that is formed by the positive wording of items (reverse-worded scoring) (
Perera et al. 2017). Although it has been translated into 28 different languages and used mostly in adult populations within both general and clinical settings (
Townsend and Medvedev 2022), during the last decade, the PSS-10 was also validated for use in adolescents in Russian (
Marakshina et al. 2024), Chinese (
Chen et al. 2024), and Danish (
Lindholdt et al. 2022) populations. Additionally, it has been used to investigate perceived stress in relation to suicidal behaviors in early adolescents (
Chen and Kuo 2020), future mental disorders (
Lindholdt et al. 2022), gaming addiction among Saudi adolescents (
Rajab et al. 2020), girls with polycystic ovary syndrome (
Khafagy et al. 2020), etc.
The Adolescent Stress Questionnaire (ASQ) consists of 58 items that evaluate the following 10 domains which depict stress-inducing situations: (i) family living conditions, (ii) academic performance, (iii) school attendance, (iv) romantic relationships, (v) peer pressure, (vi) teacher interaction, (vii) uncertainty regarding the future, (viii) conflict within the school/leisure environment, (ix) financial pressure, and (x) emerging adult responsibility. The tool is rated on a 5-point Likert-type scale, with answers ranging from 1 = not at all stressful to 5 = very stressful. Higher scores indicate greater levels of stress in each life domain (
Byrne et al. 2007).
2.3. Linguistic Validation
Before the present validation study, PSS-10 had already been translated and validated in Greek, as previously mentioned, but only for use in adults (
Andreou et al. 2011;
Katsarou et al. 2012). We obtained permission from Mapi Research Trust to adapt PSS-10 into a more adolescent-friendly version in Greek, as opposed to the one with the more formal (use of plural of nobility) and sophisticated language that already existed for use with adults (
Andreou et al. 2011;
Katsarou et al. 2012), to ensure clarity and accessibility, even for students who are not highly proficient in the language.
For the translation process, taking into consideration how language and cultural contexts may affect adolescents’ interpretation of the items, we followed the cross-cultural translation guidelines recommended by the International Quality of Life Assessment Project (
Bullinger et al. 1998). The forward translation was independently carried out by bilingual translators, and minor discrepancies were resolved by the research team. The translated version was then backtranslated by additional bilingual translators. Finally, the tool was administered to 10 Greek adolescents, who were asked to identify any difficulties related to the comprehension, layout, and style of the e-tool, as well as to provide feedback and suggestions on wording (
Kyriazos 2017).
2.4. Statistical Analysis
Quantitative variables were expressed as mean values (SD), while qualitative variables were expressed as absolute and relative frequencies.
A confirmatory factor analysis (CFA) with the maximum likelihood procedure was conducted to test how well the two-factor PSS-10 original structure fits the data. The variance of the latent constructs was fixed at one during parameter estimation, and the factors were allowed to be correlated. The fit of the CFA model was assessed using the chi square (χ
2) method, the comparative fit index (CFI), the goodness of fit index (GFI), SRMR (Standardized Root Mean Squared Error), and the root mean square error of approximation (RMSEA) (
Mueller 2000). There are several guidelines for interpreting the fit of a model based on these indicators (
Bentler 1992;
Greenspoon and Saklofske 1998;
Hu and Bentler 1999). For the CFI and GFI indices, values close to or greater than 0.95 are taken to reflect a good fit to the data. RMSEA values of less than 0.05 indicate a good fit, and values as high as 0.08 indicate a reasonable fit. SRMR values of less than 0.08 indicate a good fit.
Since the original structure was not satisfactory, exploratory factor analysis (EFA) was carried out to evaluate construct validity, disclose underlying structures, and reduce the number of variables. Principal component analysis (PCA) was chosen as the extraction method using Varimax rotation. The Kaiser–Meyer–Olkin procedure for measuring sample adequacy was applied. The cut-off point for factor loadings was 0.40, and for Eigenvalues, it was 1.00. Internal consistency reliability was determined through the calculation of Cronbach’s alpha coefficient. Scales with reliabilities equal to or greater than 0.70 were considered acceptable. Convergent validity was tested through intercorrelations (via Pearson’s r) among the scales belonging to the PSS-10 as well as through the correlations (via Pearson’s r) between ASQ and PSS-10 scales. Discriminant construct validity was evaluated by analyzing the association between the PSS-10 scales and gender, grade, diploma grade, and systematically following a program in everyday life using Student’s t-tests or analysis of variance (ANOVA).
All reported p-values are two-tailed. Statistical significance was set at p < 0.05, and analyses were conducted using the SPSS statistical software (version 26.0) and STATA (version 15).
4. Discussion
This is the first validation study of PSS-10 in a Greek population of middle adolescent students. The findings indicate that the validated Greek version of the PSS-10 (adolescent form) can be used as a rapid sound measure in future studies in Greek adolescent populations. However, this study’s confirmatory factor analysis (CFA) did not find the original two-factor structure of the scale satisfactory, so exploratory factor analysis (EFA) was used. Other researchers have also used exploratory factor analysis and revealed a two-factor structure for the PSS-10 (e.g.,
Chen et al. 2021). The original scale’s two factors which are interpreted by researchers as “Perceived Helplessness or Distress” (negatively phrased items) and “Perceived Self-Efficacy or Coping” (positively phrased items) have been revealed in previous validation studies in adolescents (e.g.,
Chen et al. 2024;
Liu et al. 2020;
Marakshina et al. 2024). Still, the scale’s dimensionality remains a topic of ongoing debate in the literature (
Pretorius 2023); Cohen and Williamson suggested the unidimensionality of the PSS-10 as a measure of perceived stress comprising dimensions of positive and negative items (1988), while other researchers reported a two-factor structure (e.g.,
Ruisoto et al. 2020), a three-factor structure (e.g.,
Bradbury 2013), and a bifactor structure consisting of a total scale and two subscales (e.g.,
Denovan et al. 2019). Regarding the factor structure analysis used for PSS-10, most studies have relied on the perspective of classical test theory (CTT), specifically exploratory factor analysis and confirmatory factor analysis (
Pretorius 2023). Our study’s exploratory factor analysis results showed that the structure of the Greek adolescent version of the scale comprises two factors, one concerning the perception of coping and the other concerning the perception of control. An inability to cope and a loss of control are often the sources of stress and vulnerability of adolescents, as AAP states (
American Academy of Pediatrics 2025), and the relationship between coping and psychological wellbeing has been shown to be mediated by the extent of perceived sense of control; strategies reflecting more engaged coping have been associated with more sense of control (
Dijkstra and Homan 2016). Additionally, concerning Greece, coping strategies and locus of control have been shown to affect adaptation in the face of difficulties in Greek students (
Leontopoulou 2006). From this perspective, Greek adolescents may perceive stress not as perceived helplessness and perceived efficacy, but as perceived lack of coping and perceived lack of control. Indeed, cultural differences have been found to affect PSS scoring in studies investigating perceived stress in various populations (e.g.,
Gamonal-Limcaoco et al. 2022;
Vallejo et al. 2018).
This study’s results support the adequate internal consistency of the Greek version of PSS-10 in assessing perceived stress of adolescents, as found by researchers in other countries (e.g.,
Liu et al. 2020;
Marakshina et al. 2024). Additionally, the significant correlations found between ASQ and PSS-10 scores show the tool’s acceptable convergent validity for stress-inducing situations, a finding also similar to that of other researchers who have tested it for stressful life events (e.g.,
Liu et al. 2020). According to our convergent validity analysis, the sample students felt more stressed due to their romantic relationships, financial issues, home life, and peer relationships regarding their perception of coping and due to peer pressure and teacher interactions regarding their perception of control.
Concerning the scale’s discriminant validity, this study’s results showed no significant differences in perceived stress between boys and girls, as also reported by
Varsha and Jain (
2023) regarding adolescents in India. Nevertheless, girls were found to have higher levels of perceived stress by
Hampel and Petermann (
2006) in Austria,
Thorsén et al. (
2022) in Sweden and Bulgaria, and
Kaczmarek and Trambacz-Oleszak (
2021) in Poland, while
Thaker and Verma (
2014) in India found that boys have higher perceived stress. Our finding, however, could be impacted by the fact that the majority of our sample, namely 73.4%, consisted of females. Our study’s results showed no significant difference regarding the grade students attended or their diploma grade, as well. Nevertheless, the study identified the importance of routines as a buffering effect, showing that students who stick to a consistent time schedule for their daily program appear to have a reduced perception of stress. This finding corroborates those of other researchers that have shown the positive effect of routines in adolescents, such as those regarding sleep (
Buxton et al. 2015), mental health (
Koome et al. 2012), academic success (
Roche and Ghazarian 2012), and development in young adulthood (
Barton et al. 2019). The predictability of a routine seems to help soothe adolescents’ mind, offering a sense of security and stability during times of crises, as shown in studies conducted during the COVID-19 pandemic (e.g.,
Ren et al. 2021). There is also a biological explanation for this phenomenon, as daily activity, the timing of meals, and sleep onset and ending are strongly coupled to the circadian biological clock, with uncoupling being a major stressor on its own (
Agorastos et al. 2020;
Nader et al. 2010;
Nicolaides et al. 2017).
Moreover, the findings of this study indicate that Greek adolescents who face stressful life events experience high levels of perceived stress. Stressful events regarding home life, romantic relationships, and teacher interaction seem to be among the most stressful events for Greek adolescents, leading to a greater sense of helplessness and a lack of self-esteem against these stressors. Previous studies agree that adolescents’ perceived stress is significantly influenced by their family environment and financial conditions. Supportive family relationships are associated with lower stress levels, whereas family conflicts, economic hardships, and a lack of parental support can exacerbate stress (
Conger et al. 2010). Adolescents from economically disadvantaged backgrounds often experience heightened stress due to concerns about family financial stability and their future financial independence (
Mistry et al. 2009). Research also highlights that uncertainty regarding future career prospects, education, and societal expectations contributes to stress, with many adolescents expressing anxiety over their ability to meet future responsibilities (
Arnett et al. 2014). These stressors can lead to adverse psychological outcomes, including anxiety and depressive symptoms, particularly among those with fewer coping resources (
Hampel and Petermann 2006).
Finally, social and interpersonal relationships also provide several stressors and significantly impact adolescents’ perceived stress. Peer pressure to conform to social norms, engage in risky behaviors, or maintain a certain social image can lead to psychological distress (
Santor et al. 2000). Romantic relationships, while a source of emotional support, can also introduce stress due to conflicts, breakups, and a fear of rejection (
Zimmer-Gembeck et al. 2001).