Peer victimization is recognized as a pressing public health issue, affecting ∼1 in 5 youth. Although extensive research demonstrates the negative effects of peer victimization on youth mental health, considerably less is known about if and how peer victimization adversely impacts physical health. Focusing on studies published in the past 5 years, this state-of-the-art review synthesizes recent research examining the relationship between peer victimization and physical health outcomes among children and adolescents. In addition to reviewing evidence for associations between peer victimization and global subjective health indices (eg, somatic symptoms), I highlight several biological sequelae of victimization (eg, cortisol dysregulation, inflammation) that may increase long-term risk for illness and disease. I conclude by considering strengths and limitations of existing work and suggesting several key directions for future research. I also discuss implications for practitioners and the role primary care providers can play in promoting health among peer victimized youth.
Approximately 1 in 5 school-aged youth have been victimized by their peers.1 Several decades of research have established that peer-victimized youth experience elevated risk for a range of negative outcomes, including academic problems, interpersonal difficulties, and psychopathology.1,2 In turn, both the American Medical Association3 and the National Academies of Sciences, Engineering, and Medicine4 recognize bullying as a serious threat to children’s healthy development.
As peer relationships become more developmentally significant across childhood and into adolescence,5 being the target of peer abuse can take a significant toll on youth’s well-being. With researchers building on previous work that documents deleterious effects of peer victimization on children’s and adolescents’ mental health,6 the past decade has seen growing interest in the effects of peer victimization on youth physical health, both in terms of self-reported (eg, somatic symptoms)7,8 and biological9–11 (eg, telomere length) outcomes. Despite recent accelerations in research on the physical health toll of peer victimization, this contemporary body of work has yet to be holistically synthesized.
Rather than providing a scoping review12–14 or theoretical narrative,15 in this state-of-the-art review, I provide an up-to-date account of research on peer victimization and physical health from the past 5 years. In this review, peer victimization is defined broadly as being the target of direct (eg, physical or verbal attacks) or indirect (eg, rumor-spreading, exclusion) peer aggression. Although bullying, which involves repeated, intentional aggression characterized by a power imbalance, is specifically examined in some reviewed studies, I use the term “peer victimization” to broadly encompass bullying and other forms of peer abuse. Specifically, I synthesize findings from recent studies examining links between peer victimization and (a) subjective health symptoms, (b) stress physiology, and (c) inflammatory and genetic biomarkers during childhood and adolescence. Key strengths and limitations from existing work are then discussed, followed by suggestions for future research and implications for pediatric practitioners.
Peer Victimization and Physical Health
Recent research provides mounting evidence that peer victimized children and adolescents experience risk for a range of physical health problems. Some problems can be perceived and reported on directly by youth (eg, headaches, stomachaches); others can only be identified through biological sampling (eg, inflammation). I start by reviewing studies examining associations between peer victimization and subjective health and then turn to research investigating biological sequelae of peer victimization.
Subjective Health Symptoms
Research from the past 5 years has been dominated by a focus on subjective (ie, self-reported) global health symptoms, with most studies relying on adolescent samples and demonstrating that peer-victimized youth report elevated concurrent16–24 and long-term24–29 somatic symptoms (eg, nausea, pain), even when accounting for previous health.20,24,30 In studies focusing on specific types of subjective health problems, sleep has received the most attention. Mounting evidence suggests that victims report worse sleep quality concurrently31–34 and over time.35,36 However, these effects appear less robust at the daily level,37 and poor sleep quality can also confer risk for later peer victimization.38 Sleep duration patterns have been mixed, with studies reporting peer victimized youth getting both reduced26,33,34,39 and prolonged sleep.26,27
When distinguishing between types of peer victimization, more pronounced health problems have been documented among targets of social or relational victimization (eg, rumor-spreading, exclusion), compared with physical victimization (eg, punching, shoving).20,31,40,41 These findings parallel previous research revealing greater negative psychological effects of indirect, covert forms of victimization.42 Among studies considering online victimization, some findings indicate a significant association between cybervictimization and adolescent somatic symptoms,26 including compromised sleep,31,43,44 whereas others show that traditional victimization, but not cybervictimization, predicts physical distress.45
New evidence also highlights heterogeneity in the effects of peer victimization on subjective health. For example, victimized adolescents report more somatic complaints if their classmates19 or friends17 are not victimized by peers, results consistent with a “healthy context paradox,”46,47 wherein victimized youth experience more distress in settings where bullying is less common (ie, “it must be my fault”). Other research documents fewer sleep problems among victimized children perceiving high social support.32,48 Studies testing mediation, in turn, implicate internalizing symptoms,16,26 ruminative coping,43 and young adult workplace revictimization25 as putative mechanisms linking adolescent peer victimization to physical health symptoms.
In summary, corroborating previous work,7,8,22 recent studies document impaired subjective health among peer-victimized youth, and new findings suggest that victimization type and broader social-contextual factors can alter such associations. Longitudinal studies have also highlighted transactional links between youth’s social experiences, psychological well-being, and health over time.
Stress Physiology
There has been a growth in research investigating whether peer victimization “gets under the skin” to alter youth’s physiologic functioning.49 Extending from biological embedding models,50–52 peer victimization is thought to alter underlying stress-sensitive physiologic systems, with accumulation of biological wear-and-tear increasing long-term risk for disease.53
Research on peer victimization and stress physiology has mainly been focused on the hypothalamic-pituitary-adrenal axis, a critical part of the stress response system, and cortisol. Cortisol is a biological marker of stress that exhibits a diurnal secretion pattern. As demonstrated in a 2019 systematic review, effects of peer victimization on salivary cortisol have been inconsistent54 ; data from recent studies show that victimized youth exhibit both elevated55,56 and blunted57 cortisol activity. Such differences may partially be driven by pubertal status, with blunted patterns being more common among (postpubertal) adolescents than children.54 Additionally, in new work examining links between peer victimization and hair cortisol over approximately a decade, hair cortisol concentrations at age 17 varied depending on the chronicity and severity of peer victimization across childhood and adolescence.58 Because most investigations have relied on single time point designs, heterogeneity in developmental history may also elucidate seemingly inconsistent findings.
Although little research has been conducted to explore possible links between peer victimization and autonomic functioning, one recent study examined associations between adolescent peer victimization and respiratory sinus arrhythmia (RSA; parasympathetic indicator) as well as skin conductance level (SCL; sympathetic indicator) at rest and in response to a laboratory-based exclusion task.59 Adolescents reporting higher levels of peer victimization exhibited lower resting RSA but did not differ from nonvictimized youth on resting SCL or autonomic reactivity. In another study, relational victimization was associated with lower heart rate variability (ie, attenuated autonomic flexibility) but was unrelated to resting heart rate among children.60
It is also worth noting that certain physiologic patterns moderate the effects of peer victimization. For example, peer victimization is more strongly associated with depressive symptoms among youth exhibiting blunted RSA59 and SCL61 reactivity and heightened morning cortisol secretion,62 suggesting that individual differences in biological sensitivity to context influence the health toll of peer victimization. In sum, despite evidence for connections between peer victimization and autonomic functioning, further investigations are needed to elucidate discrepancies across different outcomes, study settings, and modeling approaches.
Inflammatory and Genetic Biomarkers
Studies have also examined peer victimization–related variations in inflammatory and genetic biomarkers. Extending from earlier evidence that childhood peer victimization predicts heightened inflammation in adulthood,9 researchers in several recent studies investigated similar links, with findings varying by victimization type, biomarker, and time frame. In a cross-sectional study of adolescents, physical victimization was associated with lower levels of C-reactive protein (CRP) and interleukin-6, whereas social victimization was associated with higher CRP and unrelated to interleukin-6.40 Additionally, a 50-year prospective longitudinal study showed that childhood peer victimization predicted higher CRP in adulthood, even after accounting for other risk factors (eg, childhood health, adult social class).63 Links between victimization and inflammation can also vary across youth, such that peer victimization predicts greater inflammatory reactivity among cognitively vulnerable adolescents (eg, high hopelessness, self-blame).64
Some researchers have also considered whether peer victimization alters genetic expression, specifically telomere length. A shorter telomere indicates more biological aging, and this can vary depending on stress exposure. In two recent studies, adolescent targets of social or relational, but not physical, victimization had shorter telomeres,41,65 suggesting that experiencing exclusion and reputational harm can increase vulnerability to later health problems (eg, diabetes66 ; cardiovascular disease67 ) via changes to genetic factors. However, both studies assessed victimization and telomere length concurrently, leaving uncertainty about directionality or causality. Indeed, genetic factors can also increase youth’s vulnerability to peer victimization initially68 or amplify the health ramifications of victimization.69,70 Longitudinal studies tracking the coevolution of social stress and genetic expression over time will be critical for disentangling temporal sequencing.
Key Limitations and Future Directions
This review highlights considerable advances in the study of peer victimization and health over the past 5 years. Recent research suggests that peer victimization predicts worse subjective health in the short- and long-term and, by incorporating cutting-edge methodologies and interdisciplinary theoretical frameworks, identifies biophysiological correlates of peer victimization across childhood and adolescence. Nevertheless, several consistent limitations and corresponding opportunities for future research warrant discussion.
Despite increased use of “objective” health indicators (eg, salivary sampling, blood draws), recent studies still heavily rely on self-reported health. It is increasingly feasible to collect active and passive data from youth as they navigate their everyday lives.71,72 Supplementing one-time self-reports with brief, repeated mobile assessments, biomarker sampling (eg, daily cortisol), and passive physiologic monitoring (eg, heart monitor, actigraphy watches73 ) provides novel opportunities to improve ecological validity by capturing youth peer experiences and health in vivo. For researchers collecting ambulatory or laboratory-based biological data, extreme care should be taken in applying appropriate sampling and statistical procedures.74 Wide variations in methodologic and analytic decisions (eg, artifact detection; covariate inclusion) likely account for some discrepancies in the findings previously discussed.
Our understanding of contexts that promote versus undermine the health of peer victimized youth also remains sparse; there is now a critical need to identify how and for whom peer victimization gets under the skin. For example, surprisingly few studies examine victimization-related health among youth with chronic illness.21,23 Studying the experiences of those already at heightened risk for bullying and health problems, such as youth with asthma or chronic pain,75,76 could offer novel treatment insights. More generally, consideration of risk and protective factors in youth’s school, family, and community settings can facilitate the development of contextually informed interventions.
Finally, much of the reviewed research was cross-sectional. Increased reliance on longitudinal data will shed further light on how peer victimization prospectively shapes health25,28,63 and whether peer victimization is more detrimental for health during certain developmental periods.58 Indeed, most of the studies reviewed here focused on the adolescent years, leaving open questions about the role of early experiences. Longitudinal studies of peer victimization can also provide rigorous tests of biological embedding by accounting for important historical factors, including youth’s earlier health,29,31 adversity exposure (eg, family aggression),25 and victimization chronicity.28
Implications for Practitioners
Peer-victimized youth experience elevated vulnerability for health problems, and early detection is essential to reduce health risks. Practitioners are well-positioned to consider if and how peer victimization contributes to young patients’ symptomology. For example, if a child complains of nausea and sleeping troubles without a clear medical origin, pediatricians may gain insight by asking youth about their peer relationships and experiences at school or online. Given that being the target of social manipulation (eg, rumor-spreading) appears particularly consequential for health, practitioners should screen for covert forms of peer abuse in addition to considering youth’s experiences with verbal or physical peer aggression. Additionally, insofar as positive relationships appear to mitigate the health toll of victimization, pediatricians can evaluate children’s and adolescents’ access to social supports at home and school.
Pediatricians should also communicate with parents about the ways that peer victimization could interfere with their children’s health. Some parents may view bullying as a harmless rite of passage, and practitioners play a critical role in raising awareness of its serious health consequences. Encouraging parents to create open channels of communication with their children could facilitate earlier detection of social problems and corresponding intervention (eg, offering support to child; contacting school). Thus, parents, practitioners, and other adults may have opportunities to positively shape youth’s everyday environments in ways that prevent long-term health risks.
Acknowledgments
Thank you to Faizun Bakth, Alexandra Ehrhardt, and Leah Lessard for providing feedback on an earlier draft of this article.
Dr Schacter conceptualized, wrote, and revised the manuscript; the author approved the final manuscript as submitted and agrees to be accountable for all aspects of the work.
FUNDING: No external funding.
References
Competing Interests
POTENTIAL CONFLICT OF INTEREST: The author has indicated she has no potential conflicts of interest to disclose.
FINANCIAL DISCLOSURE: The author has indicated she has no financial relationships relevant to this article to disclose.
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