Nipah virus destroyed my personal, family, and social life: stories of the hardship faced by Nipah survivors in Bangladesh.

Internalizing problems, such as depression and anxiety, are highly prevalent in pediatric populations and significantly contribute to difficulties in functioning across multiple domains (e.g., adaptive, interpersonal, academic) and settings (e.g., home, school, community) [–]. In children and youth, functioning refers to the capacity to adapt to the demands of home, school, and community life [, ], and emphasizes the ability to meet age- and culturally specific expectations in different domains, including academic achievement, peer relationships, leisure, family functioning, and adaptive skills (e.g., communication, health and safety, self-care). Within each domain, functioning exists along a continuum, where competency or capacity are represented at one end, and impairment at the other []. For internalizing problems (i.e., depression, anxiety), symptoms and functioning are closely related. Symptoms, such as anhedonia, low mood, or excessive worrying, can negatively impact a child’s capacity to adapt to their demands, which may manifest as poor academic performance, interpersonal conflict, or reduced engagement in leisure activities. Functional impairment associated with mental health challenges is a key diagnostic criterion (i.e., DSM-5-TR; ICD-11) for internalizing disorders, and carries long-term risks that can persist into adulthood, including further mental health complications, physical health challenges, social drift, delinquency, homelessness, and suicide [–]. Youth with more severe functional impairments are also more likely to access outpatient mental health services as compared to those with less severe or no functioning difficulties []. In the context of mental health research with children and adolescents, functioning is often not examined as a primary outcome []. For example, a systematic review of outcomes measured in adolescent depression studies indicated 94% of studies measured symptom severity while only 52% measured functioning []. There is often an assumption that symptom reduction will directly lead to improved functioning, yet the magnitude of association between the symptoms and functioning is only moderate [, ], suggesting functioning can fluctuate independent from symptom severity, and vice versa. Prioritizing symptom reduction over functional improvement as the primary outcome in the treatment of pediatric depression and anxiety can obscure the true impact of interventions, with potential consequences for meeting patient needs and effectively allocating resources [, ]. Further, stakeholder consensus projects, including those conducted by the International Consortium for Health Outcomes Measurement (ICHOM), have shown that adolescents place high importance on functional improvements [, ], and treatments that target improvements in daily functioning over symptom alleviation are more appealing to adolescents [], underscoring the need for treatments that address more than just symptom severity. While pharmacologic and psychotherapeutic interventions can be effective in reducing symptom severity [, ], it is less clear whether treatment may also support improvements in functioning. Determining treatment efficacy based solely on symptom reduction potentially limits the acceptability and relevance of mental health interventions that are evaluated for use with youth. To fully understand treatment effectiveness, research evaluating mental health interventions for children and youth should assess both internalizing symptom severity and functioning. Based on this gap, the following protocol proposes a systematic review and meta-analysis aimed at addressing the following question: In children and adolescents with depressive or anxious symptoms, how do psychotherapeutic or pharmacologic interventions, compared to any control group, affect symptom severity and functioning? The protocol follows the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) guidelines (supplementary material; Table S1). While similar reviews have been conducted, these studies have primarily focused on non-pediatric samples [, –], lacked quantitative meta-analyses [, , ], or did not evaluate both functioning and symptoms [, , , , ]. In addition, while traditional meta-analyses primarily focus on comparing mean differences between groups, they often overlook the variability within outcomes []. This is a critical limitation because the distribution of treatment effects can reveal important insights that mean differences alone cannot provide. Thus, this study will add to existing literature by updating prior reviews, while addressing this gap by conducting a systematic review and meta-analysis of pediatric samples with internalizing symptoms, in which both symptom severity and functioning were measured.