Stemming from positive psychology, flourishing is a construct of total well-being that reflects one's physical, socioemotional, and adaptive functioning. There are different definitions of flourishing. The Child and Adolescent Health Measurement Initiative (2022) operationalized child flourishing as the extent to which “a child is affectionate, curious, laughs, and bounces back when faced with a challenge”.1 For older children, flourishing qualities include “personal attitudes or beliefs; positive interpersonal relationships; and task-related characteristics, such as diligence and initiative”.2 Research has shown that adolescents with greater flourishing are likely to make healthier behavioral choices and perform well in school.3 Conversely, those with lower flourishing are likely to have health-risk behaviors, mental health problems, greater adjustment difficulties, and lower prosocial behavior.4,5 Furthermore, flourishing is a significant predictor of suicidal ideation, future episodes of mental illness, and mortality.6,7 Adolescence is considered a critical period for cognitive, physical, and psychological development.8,9 Flourishing during adolescence is linked to future success in career progression and taking on civic responsibilities in adulthood.10 Therefore, understanding the factors that are associated with adolescents' flourishing and managing it early in life may be an effective strategy to prevent mental illness and mortality, and ensure future success in their careers and civic responsibilities.

There is a considerable research base that has explored the associations of adverse childhood experiences (ACE) and other individual and household demographic variables with flourishing.11, 12, 13, 14, 15 For example, studies indicate that adolescents who have experienced more adverse events in childhood are less likely to flourish, with the likelihood of flourishing decreasing as the number of such experiences increases.11,12 Individual demographic variables such as sex and race also play significant roles. Some research suggested that adolescent girls are more likely than boys to report flourishing indicators,11,14 though other study have found the opposite, with boys more likely to report flourishing.13 Additionally, flourishing varies significantly across different racial groups, with Hispanic adolescents more likely to flourish than their peers of non-Hispanic White, Black, and other race group.11,14 Household demographic factors, including income and parental education, can also significantly influence adolescent flourishing. Higher household income (as measured by the Federal Poverty Level (FPL)) is associated with an increased likelihood of flourishing in adolescents.11 Parental education serves as a critical moderator, shaping the relationship between parental support, educational aspirations, and life satisfaction, all of which are closely linked to adolescence's flourishing.15

Chronic health conditions and disabilities are associated with many aspects of adolescents' lives,16 and several studies have explored the association of different chronic health conditions and disabilities with adolescents’ flourishing.17, 18, 19, 20 For instance, research showed that adolescents with moderate-severe autism tend to have decreased flourishing.17 Similarly, Stough et al. (2015) demonstrated that adolescents with epilepsy exhibited significantly lower levels of flourishing compared to their peers without epilepsy, with epilepsy severity emerging as a key predictor of flourishing.18 Nabors et al. (2016) reported that adolescents with asthma showed lower flourishing than those without asthma.19 Parsons et al. (2024) studied the relationship between chronic pain and flourishing in adolescents, and their findings showed that adolescents living with chronic pain reported low levels of flourishing.20 These studies suggest that adolescents with a particular chronic health condition or disability tend to have a lower level of flourishing than those without such conditions.

Adolescents often experience multiple chronic health conditions and disabilities simultaneously. For example, according to the 2022 National Survey of Children's Health (NSCH), 20.8 % of children and adolescents have two or more health conditions or disabilities, slightly higher than the 19.9 % who have only one.21 Despite this, there is limited research on the association of multiple chronic health conditions or disabilities with adolescents' flourishing. Foster et al. (2023) found that adolescents with chronic pain and an additional emotional, developmental, or behavioral comorbidity had 13 times lower odds of flourishing—a significantly higher risk than the 2.33 times lower odds observed in those with only chronic pain compared to their typical peers.22 This finding seemed to suggest that the number of health conditions or disabilities might be associated with adolescents flourishing differently. To our knowledge, no studies have specifically examined the association of varying numbers of chronic health conditions and disabilities with adolescent flourishing. To address this gap, this study explored the additive associations of multiple chronic health conditions or disabilities with flourishing among adolescents in the U.S., which is estimated to be more than 1.3 million young people with chronic health conditions or disabilities.23 Specifically, the purpose of this study was to examine the associations between the number of chronic conditions or disabilities and flourishing among adolescents in the U.S.