Health-related quality of life of adolescents: Relations with positive and negative psychological dimensions

Abstract This study aims to analyse: the relationship between socio-demographic variables and overall HRQoL and its domains; the predictor role of negative psychological dimensions (anxiety, depression and stress) and positive ones (subjective happiness, self-esteem and life satisfaction) on overall HRQoL and its domains. The sample consisted of 465 Portuguese students (53.5% girls), aged 13–18 years (M = 15.20, SD = 1.16). The students answered to the following measures: Kidscreen-27, Subjective Happiness Scale, Students’ Life Satisfaction Scale, Self-Esteem Rosenberg Scale and Depression, Anxiety and Stress Scale-Children. Gender, age and chronic disease predicted perceptions of some HRQoL domains. The results showed that both negative and positive psychological dimensions predicted HRQoL and its domains. Depressive symptoms were a negative predictor and self-esteem a positive predictor of overall HRQoL and all of its domains. These results create opportunities for new insights into health and optimal functioning of adolescents from an ecological perspective.


Quality of life and health-related quality of life
suggested that HRQoL is associated with physical (e.g. health), individual (e.g. self-esteem, positive and negative emotions, stress) and social (e.g. satisfaction with social support, relations with family and peer group) dimensions (Gaspar, Matos, Pais Ribeiro, Leal, & Ferreira, 2009;Harding, 2001;Soares et al., 2011). Therefore, the promotion of HRQoL in adolescents requires the adoption of an ecological perspective (Bronfenbrenner, 2005), since it is influenced by individual and contextual factors. In fact, adolescents live in several systems, which may have influence on their values, beliefs and attitudes and, subsequently, on their QoL (Schalock, 2004).

HRQoL in adolescence and gender, age and chronic disease
It becomes pertinent to know what factors contribute to adolescents' health and well-being in order to promote adolescents' positive development (Park, 2004). This positive approach considers that adolescents are 'producers of their own development' and, therefore, it is more than solve or prevent problems (Seiffge-Krenke, Kiuru, & Nurmi, 2010). This is particularly important in this developmental phase, because adolescence is a crucial period in life span, characterized by concomitant changes, at biological, psychological, social and cognitive levels (Proctor, Linley, & Maltby, 2009;Salmela-Aro & Tuominen-Soini, 2010) that might influence the adolescents' perception of HRQoL (Gaspar et al., 2010). Also, in this phase, adolescents begin to take autonomy to make their own lifestyle choices (Lenz, 2004) and these might have impact on their long-term health and well-being (Simões, Matos, & Batista-Foguet, 2008;World Health Organization (WHO, 2016). For example, WHO (2012) suggested that substance use (tobacco/alcohol/drug) is one of the risks in adolescence, also encouraged by peer pressure. In fact, Meade and Dowswell (2016) found that only social support and peers dimension of HRQoL changed over time (three years), in adolescents.
There seems to exist gender differences in children and adolescents' quality of life. Studies showed that boys reported higher levels of HRQoL, namely physical and psychological well-being, and parents' relation and autonomy, than girls (Meade & Dowswell, 2016;Ravens-Sieberer et al., 2007). In the same sense, another study revealed that girls, aged between 10 and 16, reported worse QoL in all the domains of HRQoL -physical and psychological well-being, moods and emotions, self-perception, autonomy, parent relation and home life and social acceptance -with the exception of the domain of school environment, when compared with boys (Gaspar et al., 2010). In addition, gender differences in the domains of financial resources and social support and peers were not found. On the other hand, the WHO International Report (2016) found that girls are more likely to report higher levels of peers' social support in almost all countries and at every age.
Concerning age differences, children, aged 8-11 years, showed higher levels of HRQoL, namely on physical and psychological well-being, than adolescents aged 12-18 years . In the same way, the adolescents attending the 7th school grade reported worse HRQoL in all the domains -physical and psychological well-being, moods and emotions, self-perception, autonomy, parent relation and home life, social support and peers, school environment -with the exception of the domains of financial resources and social acceptance (Gaspar et al., 2010). Older adolescents also showed worse quality of relationship with parents, than younger ones (Branje, Hale, Frijns, & Meeus, 2010). Indeed, the WHO International Report (2016) suggested that, in general, the percentage of adolescents who reported that their families are highly supportive decreased with increasing age, just like the percentage of adolescents who reported liking school.
Finally, students who reported to have a chronic disease showed lower QoL in all domains of HRQoL with the exception of school environment, where there were no significant differences (Gaspar et al., 2010).

HRQoL and positive psychological dimensions (subjective happiness, life satisfaction and self-esteem)
Some authors suggest the existence of a close relationship between the HRQoL of children and adolescents and their mental health and other positive psychological dimensions such as happiness or subjective well-being (Gaspar, Pais Ribeiro, Matos, & Leal, 2008). Actually, Zullig, Valois, and Drane (2005a) found that, in high school students, both physical and mental health contribute to the perception of quality of life. Notwithstanding, mental health seems to have a greater contribution to QoL (Zullig et al., 2005a). A Portuguese study also emphasized the strong influence of psychological factors, both direct and indirect, in the HRQoL of children and adolescents (Gaspar, Pais Ribeiro, Matos, & Leal, 2011).
Several studies have suggested that greater happiness and life satisfaction were associated with better physical and mental health (Huebner, 2004;Park, 2004, for a review;Simões et al., 2008). In particular, a study found that adolescents, aged 13-18 years, who declared to have more days of poor physical or mental health in the past 30 days, showed more dissatisfaction with their lives, independently of gender (Zullig, Valois, Huebner, & Drane, 2005b). Moreover, greater happiness and life satisfaction were associated with higher general QoL, as well as higher physical, psychological, social and environmental QoL (Abdel-Khalek, 2010). Self-esteem was also positively associated with all the domains of HRQoLphysical well-being, psychological well-being, moods and emotions, self-perception, autonomy, parent relation and home life, financial resources, social support and peers, school environment and social acceptance (Gaspar et al., 2009).
In particular, family relations and social support are reported by children and adolescents as important to their psychological well-being (Gaspar et al., 2011). Indeed, an association between parenting styles and adolescents' well-being has been suggested (Milevsky, Schlechter, Netter, & Keehn, 2007). Adolescents who consider the parenting style as authoritative (parents are both demanding and responsive) or permissive (parents are responsive but not demanding) showed higher levels of self-esteem and life satisfaction, when compared with those that consider parents as authoritarian (parents are demanding but unresponsive) (Raboteg-Saric & Sakic, 2014). In the same sense, it was found that, in high school adolescents, an authoritative parenting style was associated with higher self-esteem and life satisfaction (Milevsky et al., 2007). On the other hand, concerning adolescents' relationships with peers, adolescents who reported higher quality of friendship showed higher levels of satisfaction with life, subjective happiness and self-esteem, than those who reported lower quality of friendship (Raboteg-Saric & Sakic, 2014). Moreover, the experience of higher distress at school was strongly associated with lower happiness (Natvig, Albrektsen, & Qvarnstrøm, 2003).

HRQoL and negative psychological dimensions (anxiety, depression and stress)
HRQoL is not only associated with positive psychological dimensions, but also with negative psychological dimensions. Indeed, adolescence is a transitional period characterized by emotional demands, which may lead to the development of internalizing problems such as anxiety, depressive and stress symptoms (Phillips & Power, 2011;WHO, 2012). These symptoms, although not clinically significant, might have a negative impact on normative adolescents' HRQoL (Gaspar et al., 2010). A Portuguese study found that students, aged 10-17 years, that have comorbidity of anxiety and depressive symptoms reported poorer health and poor relationships with their peers, than those who have only anxiety or depressive symptoms (Matos, Barrett, Dadds, & Shortt, 2003).
Literature has been suggesting that severe anxiety symptoms were associated with worse QoL in the domains of family, residential environment, personal competence, social relationships, physical appearance, psychological well-being, and pain, even after controlling the socio-demographic variables (Yen et al., 2011). It was also found a negative association of social support with stress and depressive symptoms, in university students (Wang, Cai, Qian, & Peng, 2014); and between depressive symptoms and quality of adolescents' relationship with parents (Branje et al., 2010;Cheng & Furnham, 2003). Besides, Van der Giessen, Branje, and Meeus (2014) revealed that adolescents who feel that their parents do not support their autonomy (e.g. their thoughts, feelings, choices) showed higher levels of depressive symptoms over time. On the contrary, an association between an authoritative parenting style and lower levels of depression was found (Milevsky et al., 2007).

Current study
Considering the relationship between both positive and negative psychological dimensions and HRQoL, this study aims to analyse: (i) the relationship between gender, age and the presence of chronic disease, and overall HRQoL and its specific domains (physical well-being, psychological well-being, autonomy and parents relation, peers and social support, and school environment); (ii) the relationship between overall HRQoL and its specific domains and subjective happiness, self-esteem, life satisfaction, anxiety, depression and stress; (iii) the predictor role of anxiety, depression and stress, as negative psychological dimensions, and subjective happiness, self-esteem and life satisfaction, as positive psychological dimensions, on overall HRQoL and its specific domains.
Considering the previous aims and literature, it was expected that: (1) boys, younger adolescents and those who reported to have no chronic disease would present higher HRQoL in general and in specific domains; (2) overall HRQoL and its domains would be positively associated with subjective happiness, life satisfaction and self-esteem; and, on the contrary, negatively associated with anxiety, depression and stress; (3) anxiety, depression and stress would be negative predictors of overall HRQoL and its domains; whereas subjective happiness, life satisfaction and self-esteem would be positive predictors of HRQoL and its domains.

Participants
The sample consisted of 465 Portuguese students, of which 53.5% were girls. Students' age varied between 13 and 18 years (M = 15.20, SD = 1.16). Subsequently 34.0% attended the 9th grade, 24.3% 10th grade, 23.2% the 11th and 18.5% the 12th. Concerning students' health, the majority of the students (85.2%) reported to not have a chronic condition or disease.
Regarding professional situation of parents, 89.9% of the students' fathers and 81.6% of the mothers were professionally active, whereas 10.1% of the fathers and 18.4% of the mothers were not professionally active.

Socio-demographic questionnaire
It is composed by questions to characterize the sample in terms of gender, age and the presence of chronic disease. Robitail et al., 2007; Portuguese Version of . Kidscreen-27 is a reduced version of Kidscreen-52 instrument and evaluates the QoL related to health and chronic disease in children and adolescents aged 8-18 years. It consists of 27 items organized into five domains: (i) physical well-being that assesses the level of physical activity, energy and resistance, as well as the perception of the child/adolescent about their health; (ii) psychological well-being that explores the positive emotions, life satisfaction, as well as feelings of sadness and loneliness;

Kidscreen-27. (Original Version of
(iii) autonomy and relationship with parents that measures the quality of interaction between the child/ adolescent and their parents and how they feel loved and supported by the family, and it also examines the perception of the level of autonomy and quality of economic resources; (iv) social support and peer group that considers social relations and friends, evaluating the quality of the interactions between the child/adolescent and the peer group and the perceived support; and (v) the school environment that explores the perception of the children/adolescents regarding their cognitive abilities, learning and concentration, as well as their feelings regarding the school, also evaluating their perception of the relationship with teachers. Higher scores indicate better QoL and well-being of children and adolescents in the respective dimension. In the study that assesses Kidscreen structural and cross-cultural validity, the Cronbach alphas ranged from .78 to .84 in different domains (Robitail et al., 2007). In the Portuguese version, the alpha obtained for the total scale was .89 . The alphas in this sample are presented in Table 1. Lyubomirsky & Lepper, 1999; Portuguese version of Freire, Vilas Boas, & Teixeira, 2016). This scale has four items that assess the overall subjective happiness. The answers are given in a visual analogue scale with 7 positions, where 1 corresponds to the lowest level of happiness and 7 to the highest level of happiness. The total score is obtained through the mean of responses in the four items (the fourth was reversed). Higher scores indicate greater subjective happiness. The alpha in this sample is presented in Table 1.  , 2007). The SLSS consists of seven items that assess satisfaction with the overall life in children and adolescents aged 8-18 years. The response scale ranges from 1 (strongly disagree) to 6 (strongly agree), therefore, higher scores indicate higher levels of life satisfaction. The Portuguese validation of SLSS obtained a Cronbach alpha of .89 for the total scale (Marques et al., 2007).

Subjective happiness scale. (Original version of
The alpha in this sample is presented in Table 1. Rosenberg, 1965; Portuguese version of Santos & Maia, 2003). This scale has 10 items and evaluates self-esteem. The answers are given in a Likert scale ranging from 1 (strongly disagree) to 4 (strongly agree), where higher levels correspond to higher self-esteem. The Portuguese validation found a Cronbach alpha of .86. The alpha in this sample is presented in Table 1.  . The alphas in this sample are presented in Table 1.

Procedure
This study used a cross-sectional design, since the assessment occurred in one single moment. Data were collected in the school context, after the approval of the School Executive Staff. Parents were also asked about their consent for the students' participation. The adolescents' participation was voluntary and informed consent was applied. Under the supervision of the research team, teachers administered the battery of questionnaires during class time.

Data analysis
Frequencies, means and standard deviations were calculated in order to characterize the sample in terms of socio-demographic and psychological variables. To analyse the relationship between the variables at study, a Pearson's Correlation Coefficient was calculated. Independently sample T-tests and MANOVAs were performed to examine the differences in psychological variables according to gender.
To explore the predictors of overall HRQoL and its domains, hierarchical regressions were conducted (method enter). In the first step were included the socio-demographic variables associated with the dependent variable; in the second step the negative psychological variables; and in the third step the positive psychological variables.

Preliminary analyses
Descriptive measures of the psychological variables were calculated (Table 1). On average, this sample of students reported perceptions of high levels of physical and psychological well-being, autonomy and parents relation, peers and social support, school environment and overall HRQoL; subjective happiness, satisfaction with life and self-esteem, as well as low levels of anxiety, depression and stress symptoms (high or low, meaning above or below average values). Results of Pearson's Correlation Coefficient between psychological variables (Table 2) revealed that perceptions of higher overall HRQoL, higher physical and psychological well-being, higher autonomy Table 2. results of Pearson's coefficient correlation between psychological variables. ***p < .001. Variables and parents relation, better peers and social support, and better school environment were associated with greater subjective happiness, life satisfaction and self-esteem, as well as lower levels of anxiety, depression and stress symptoms. There were significant differences on psychological variables according to gender. Boys showed perceptions of higher levels of overall HRQoL (t (438) = -5.08, p < .001), physical (F (1, 438) = 80.47, p < .001) and psychological well-being (F (1, 438) = 15.93, p < .001), and autonomy and parents relation (F (1, 438) = 11.41, p = .001), than girls. However, there were no gender differences on peers and social support (F (1, 438) = 1.40, p = .24) and school environment (F (1, 438) = 1.24, p = .27).
The presence of a chronic disease or physical condition (students were asked if they have a chronic disease or physical condition) was significantly associated with the perception of lower physical wellbeing (r = -.16, p < .001).
The socio-demographic variables significantly associated with overall HRQoL and its domains were included in the respective regression analysis.

Predictors of overall HRQoL
The results of the hierarchical regression revealed that gender, age, depressive symptoms, subjective happiness, life satisfaction and self-esteem were significant predictors of overall HRQoL perceptions (Table 3). Thus, being boy, younger, with greater subjective happiness, life satisfaction and self-esteem, as well as lower levels of depressive symptoms predicted perceptions of better HRQoL. The final model explained 63% of the variance.

Predictors of physical well-being
The hierarchical regression revealed that gender, age, chronic disease, depressive symptoms, subjective happiness and self-esteem were predictors of physical well-being (Table 3). Thus, being boy, younger, having no chronic disease or physical condition, showing higher levels of subjective happiness and self-esteem, as well as lower levels of depressive symptoms, predicted perceptions of better physical well-being. Interestingly, depressive symptoms lost their predictive value (β = .04, t = .57, p = .57) in the presence of positive psychological dimensions in step 3. The final model explained 40% of the variance.

Predictors of psychological well-being
The results showed that gender, age, depressive symptoms, subjective happiness, life satisfaction and self-esteem were predictors of psychological well-being (Table 3). Thus, being boy, younger, with lower levels of depressive symptoms, as well as greater subjective happiness, satisfaction with life and self-esteem predicted perceptions of better psychological well-being. Interestingly, gender was a predictor of the perception of psychological well-being only in step 1, losing its predictive value in the presence of negative psychological dimensions in step 2 (β = .06, t = 1.57, p = .12), and positive psychological dimensions in step 3 (β = .04, t = 1.15, p = .25). The final model explained 65% of the variance.

Predictors of autonomy and parents relation
The results of the hierarchical regression revealed that gender, depressive and stress symptoms, as well as life satisfaction and self-esteem were predictors of the students' perception of autonomy and parents relation (Table 4). Thus, being boy, lower levels of depressive and stress symptoms, as well as greater satisfaction with life and self-esteem predicted perceptions of better autonomy and parents relation. Interestingly, gender lost its predictive value in the presence of the negative psychological dimensions in step 2 (β = .08, t = 1.68, p = .09), and positive psychological dimensions in step 3 (β = .04, t = .93, p = .35); while depressive (β = -.01, t = -.20, p = .84) and stress (β = -.12, t = -1.94, p = .054) symptoms lost their predictive value in the presence of positive psychological dimensions, in step 3. The final model explained 32% of the variance.

Predictors of peers and social support
The results showed that age, depressive symptoms, subjective happiness and self-esteem were significant predictors of the students' perception of peers and social support (Table 4). Therefore, being younger, lower levels of depressive symptoms, as well as greater subjective happiness and self-esteem predicted perceptions of better peers and social support. Interestingly, age lost its predictive value in the presence of negative psychological dimensions in step 2 (β = -.09, t = -1.86, p = .06) and positive psychological dimensions in step 3 (β = -.06, t = -1.38, p = .17); as depressive symptoms lost it in the presence of positive psychological dimensions in step 3 (β = -.01, t = -.19, p = .85). The final model explained 22% of the variance.

Predictors of school environment
The results revealed that depressive symptoms, life satisfaction and self-esteem were predictors of school environment perceptions' (Table 4). Thus, lower levels of depressive symptoms, as well as greater satisfaction with life and self-esteem predicted better school environment perceptions. The final model explained 20% of the variance.

Discussion
This study examined the relationship between the perceptions of HRQoL and related specific domains (physical well-being, psychological well-being, autonomy and parents' relation, peers and social support, and school environment) with age, gender, and the presence of chronic disease; and also with some negative and positive dimensions of psychological functioning. Moreover, it investigated the predictor role of those negative psychological dimensions (anxiety, depression and stress) and of positive ones (subjective happiness, self-esteem and life satisfaction) on overall as well as specific domains of HRQoL.
To know how these aspects revealed adolescents' patterns of psychological functioning was a main contribution of this study. According to our results, it was found that boys showed perceptions of higher overall HRQoL, physical and psychological well-being, and autonomy and parents' relation, than girls. In fact, being boy predicted perceptions of better overall HRQoL, physical and psychological well-being, and autonomy and parents relation, as expected. Indeed, these findings reinforce the role of gender as a main variable in terms of HRQoL. Similar to the results of previous studies (Branje et al., 2010;Gaspar et al., 2010;Ravens-Sieberer et al., 2007), being younger predicted better overall HRQoL, physical and psychological well-being, and peers and social support perceptions.
Interestingly, gender lost its predictive value for psychological well-being and for autonomy and parents' relation in the presence of both negative and positive psychological dimensions. Also age lost its predictive value in the presence of both negative and positive psychological dimensions. Therefore, psychological dimensions seemed to contribute more for these specific domains of HRQoL, than gender or age. One possible explanation may be related with the perception of HRQoL in itself, since it is defined as optimum levels of mental, physical, role and social functioning, including relationships, and perceptions of health, fitness, life satisfaction and well-being (Theofilou, 2013, p. 156). Also Gaspar et al. (2009) claimed for the importance of psychosocial variables on HRQoL.
Like what was expected (Gaspar et al., 2010), the students' perception of having no chronic disease or physical condition predicted perceptions of better physical well-being. Indeed, the presence of a chronic disease may be associated to the experience of physical symptoms (e.g. pain, fatigue) and to the need of complex daily treatments, which influence adolescents' physical well-being (Barlow & Ellard, 2006;Soares et al., 2011).
The present results show the relevance of both negative and positive psychological dimensions to HRQoL and its specific domains. Our findings highlighted that adolescents' overall HRQoL and all of its domains were predicted by lower depressive symptoms and higher self-esteem. Their perceptions on autonomy and parents' relation were also predicted by stress symptoms. Concerning the other positive psychological dimensions, overall HRQoL, physical and psychological well-being, autonomy and parents' relation, peers and social support and school environment were predicted by subjective happiness and life satisfaction.
Interestingly, the results revealed that, in the presence of positive psychological dimensions, negative psychological dimensions lost their predictive value when predicting HRQoL domains, showing that positive psychological dimensions might play a buffer role for negative psychological dimensions in adolescents and, then, should be promoted. In addition, this study showed the importance of the relation between positive and negative psychological dimensions, as they appear as independent but at the same time interrelated dimensions, being both relevant for a healthy physical, mental, familiar and social functioning.
Our findings about the specific domains of the HRQoL, make relevant a distinction between perceptions of HRQoL more related to intrapersonal/internal domains (e.g. physical well-being, psychological well-being) and to interpersonal/external domains (e.g. peers and social support, school environment). Indeed, the contribution/impact of the variables of the present study (gender, age, chronic disease and both positive and negative psychological dimensions) for intrapersonal/internal HRQoL domains was higher (in terms of the percentage of explained variance) than for interpersonal/external HRQoL domains. According to this, it seems that other variables, different from those included in this study, can play a significant role in the interpersonal/external domains of HRQoL that are more related to the characteristics of the contexts where adolescents are living. This is in line with the positive and ecological developmental perspective that highlights the importance of the several daily life contexts where adolescents live and related influence on their emergent values and meanings and, therefore, their perceptions of HRQoL. Knowing that this developmental phase is characterized by the increase of the autonomy, it becomes crucial regarding lifestyle choices, because they might have impact on adolescents' health and well-being, in adulthood. So, it is important to promote adolescents' health and well-being and, consequently, their positive development.
However, this study has some limitations that need to be addressed and oriented to future studies: (i) the sample should be extended in future studies in order to discuss regular patterns of relation between HRQoL, socio-demographic variables and positive and negative psychological dimensions; (ii) to move from a cross-sectional design, which does not allow to establish causality about predictors along age, to longitudinal designs testing the role of developmental trajectories.
Despite these limitations, this study points out considerable contributions for intervention and prevention on HRQoL. Particularly, our findings suggested that depressive symptoms and self-esteem need to be assessed and monitored, as well as defined as a target of intervention, in order to promote students perceptions' of a better HRQoL and well-being. Moreover, the intervention in negative psychological dimensions (anxiety, depression and stress) can possibly be done through the promotion of positive dimensions, like self-esteem, life satisfaction and subjective happiness. This hypothesis should be pursued in future studies. The distinction between positive and negative psychological dimensions and the buffer role of the former, make relevant the distinction between positive functioning and psychological distress. According to our results, self-esteem, life satisfaction and subjective happiness may be associated to positive functioning that could buffer the onset of psychological distress. The relation between positive functioning and psychological distress, considering the variables of this study or new ones, should be explored in future studies, along with the concept of optimal functioning. Besides, our study contributed to relevant findings about HRQoL, highlighting new directions for future research about the role of different variables affecting perceptions of HRQOL when considering intrapersonal/internal and interpersonal/external domains. Also to go a step forward, gender needs to be deeply understood to provide knowledge on gender differences in HRQoL and to support efficient interventions when working on QoL promotion for both male and female adolescents. Indeed, whether it is a question of individual traits or socialization processes is still an actual issue in this research field.
In sum, our study tried to analyse overall HRQoL, but also its specific domains, which is not very usual in the research of quality of life. Besides, the different kinds of results according to these domains open new lines of research in adolescence, creating opportunities for new insights into health, well-being and optimal functioning of adolescents from an ecological perspective.

Disclosure statement
No potential conflict of interest was reported by the authors.

Funding
This study was conducted at Psychology Research Centre [grant number UID/PSI/01662/2013], University of Minho, and supported by the Portuguese Foundation for Science and Technology and the Portuguese Ministry of Science, Technology and Higher Education through national funds and co-financed by FEDER through COMPETE2020 under the PT2020 Partnership Agreement [grant number POCI-01-0145-FEDER-007653].

Notes on contributors
Teresa Freire is assistant professor in the School of Psychology, in the University of Minho being member of the Psychology Research Center. She is the coordinator of the Research Team on Positive Development and Optimal Functioning, and supervises several PHD and Master research projects. She is author of psychological intervention programmes for promoting youth positive development, implemented in the community. She is editor of international books, author of several book chapters and articles.
Gabriela Ferreira is a research fellow at the Psychology Research Center, in the University of Minho, Portugal. She has a Masters in Health Psychology and belongs to a research team that studies the optimal functioning in several populations and contexts. She is interested in the study of subjective happiness, quality of life, and relations with positive development in children and adolescents.