Background Peer victimization is ubiquitous across schools and cultures, and has been suggested as one developmental pathway to anxiety disorders. However, there is a dearth of prospective studies examining this relationship. The purpose of this cohort study was to examine the association between peer victimization during adolescence and subsequent anxiety diagnoses in adulthood. A secondary aim was to investigate whether victimization increases risk for severe anxiety presentations involving diagnostic comorbidity. Methods The sample comprised 6,208 adolescents from the Avon Longitudinal Study of Parents and Children who were interviewed about experiences of peer victimization at age 13. Maternal report of her child's victimization was also assessed. Anxiety disorders at age 18 were assessed with the Clinical Interview Schedule–Revised. Multivariable logistic regression was used to examine the association between victimization and anxiety diagnoses adjusted for potentially confounding individual and family factors. Sensitivity analyses explored whether the association was independent of diagnostic comorbidity with depression. Results Frequently victimized adolescents were two to three times more likely to develop an anxiety disorder than nonvictimized adolescents (OR = 2.49, 95% CI: 1.62–3.85). The association remained after adjustment for potentially confounding individual and family factors, and was not attributable to diagnostic overlap with depression. Frequently victimized adolescents were also more likely to develop multiple internalizing diagnoses in adulthood. Conclusions Victimized adolescents are at increased risk of anxiety disorders in later life. Interventions to reduce peer victimization and provide support for victims may be an effective strategy for reducing the burden associated with these disorders.

Peer victimization is ubiquitous across schools and cultures, and has the potential for long-lasting effects on the well-being of victims. To date, research has focused on the consequences of peer victimization during childhood but neglected adolescence. Peer relationships and approval become increasingly important during adolescence; thus, peer victimization at this age may have a damaging psychological impact. Participants were 5030 adolescents aged 11-16 recruited from secondary schools in the UK. Self-report measures of victimization and symptoms of anxiety and depression were administered on three occasions over a 12-month period. Latent growth models examined concurrent and prospective victimization-related elevations in anxiety and depression symptoms above individual-specific growth trajectories. Peer victimization was associated with a concurrent elevation of 0.64 and 0.56 standard deviations in depression and anxiety scores, respectively. There was an independent delayed effect, with additional elevations in depression and anxiety (0.28 and 0.25 standard deviations) six months later. These concurrent and prospective associations were independent of expected symptom trajectories informed by individual risk factors. Adolescent peer victimization was associated with immediate and delayed elevations in anxiety and depression. Early intervention aimed at identifying and supporting victimized adolescents may prevent the development of these disorders.

Previous studies have linked exposure to early socioeconomic adversity to depression, but the mechanisms of this association are not well understood. Locus of control (LoC), an individual's control-related beliefs, has been implicated as a possible mechanism, however, longitudinal evidence to support this is lacking. The study sample comprised 8803 participants from a UK cohort, the Avon Longitudinal Study of Parents and Children (ALSPAC). Indicators of early socioeconomic adversity were collected from the antenatal period to 5 years and modelled as a latent factor. Depression was assessed using the Clinical Interview Schedule-Revised (CIS-R) at 18 years. LoC was assessed with the Nowicki-Strickland Internal-External (CNSIE) scale at 16 years. Using structural equation modelling, we found that 34% of the total estimated association between early socioeconomic adversity and depression at 18 years was explained by external LoC at 16 years. There was weak evidence of a direct pathway from early socioeconomic adversity to depression after accounting for the indirect effect via external locus of control. Socioeconomic adversity was associated with more external LoC, which, in turn, was associated with depression. Attrition may have led to an underestimation of the direct and indirect effect sizes in the complete case analysis. Results suggest that external LoC in adolescence is one of the factors mediating the link between early adversity and depression at 18 years. Cognitive interventions that seek to modify maladaptive control beliefs in adolescence may be effective in reducing risk of depression following early life adversity.