Adolescentes que han sufrido intimidación tienen un mayor riesgo de depresión en la edad adulta

Peer victimisation during adolescence and its impact on depression in early adulthood: prospective cohort study in the United Kingdom

Abstract

Objective To investigate the strength of the association between victimisation by peers at age 13 years and depression at 18 years.

Design Longitudinal observational study.

Setting Avon Longitudinal Study of Parents and Children, a UK community based birth cohort.

Participants 6719 participants who reported on peer victimisation at age 13 years.

Main outcome measures Depression defined according to international classification of diseases, 10th revision (ICD-10) criteria, assessed using the clinical interview schedule-revised during clinic assessments with participants when they were aged 18 years. 3898 participants had data on both victimisation by peers at age 13 years and depression at age 18 years.

Results Of the 683 participants who reported frequent victimisation at age 13 years, 101 (14.8%) were depressed according to ICD-10 criteria at 18 years; of the 1446 participants reporting some victimisation at age 13 years, 103 (7.1%) were depressed at age 18 years; and of the 1769 participants reporting no victimisation at age 13 years, 98 (5.5%) were depressed at age 18 years. Compared with children who were not victimised those who were frequently victimised by peers had over a twofold increase in odds of depression (odds ratio 2.96, 95% confidence interval 2.21 to 3.97, P<0 .001="" 1.49="" 10.9="" 18="" 29.2="" 3.63="" 43.7="" a="" adjusting="" age="" association="" at="" attributable="" be="" by="" causal="" confidence="" confounders="" could="" depression="" explained="" font="" for="" fraction="" if="" interval="" of="" p="" peer="" population="" reduced="" relation.="" slightly="" suggested="" that="" the="" this="" to="" victimisation="" was="" were="" when="" years="">

Conclusion When using observational data it is impossible to be certain that associations are causal. However, our results are consistent with the hypothesis that victimisation by peers in adolescence is associated with an increase in the risk of developing depression as an adult.

Introduction

Depression is a leading contributor to the global burden of disease.¹ The incidence and prevalence of depression increases rapidly from childhood to early adulthood, and by age 18 years the prevalence is similar to that in adults.² This has led to suggestions that school based preventive programmes could help to reduce the burden of depression. However, the results of cognitive behaviour programmes in schools have been disappointing.³

Adolescents spend more time with their peers than do children and adults, and peers are used as primary sources for social comparison and appraisal.⁴ Victimisation by peers or “bullying” has been proposed as one potentially modifiable risk factor for depression. Cross sectional studies report correlations between peer victimisation and clinical depression,^{5 6} whereas adults with depression are more likely to retrospectively report peer victimisation as a child or adolescent⁷; however, these results could be due to recall bias or reverse causality. Previous longitudinal studies have mainly examined outcomes such as internalising symptoms in childhood or adolescence^{8 9 10} rather than studying diagnoses of depression at older ages, which has more relevance for the population burden of depression that occurs mainly in adults of working age.^{11 12}

We are only aware of a small number of longitudinal studies that have prospectively investigated victimisation in relation to depression meeting diagnostic criteria in late adolescence or adulthood. Some of these did not adjust for key confounders such as baseline depressive symptoms¹³ or behavioural problems,¹⁴ which might themselves have led to both victimisation and later depression. Others^{15 16} have only found an association for children who were both victims and perpetrators of bullying. Perpetrators also display high levels of conduct problems and reactive aggression, which are themselves associated with later depression^{17 18} and may confound the association. Others have not used a well validated measure of bullying, relying on reports from single items.^{14 15 16 19} Given the limitations of previous studies, it still remains unclear whether peer victimisation during adolescence contributes to the public health burden of depression that mostly manifests in adulthood.

Using data from over 3700 families from the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort in the United Kingdom, we investigated the strength of the association between being victimised by peers in early adolescence and the emergence of depression at age 18 years, while taking account of several confounders, including previous victimisation in childhood and mental health problems. All participants with data on peer victimisation at age 13 years and at least one assessment of depressive symptoms were eligible to be included in the study. Our hypothesis was that peer victimisation during adolescence would be associated with an increased risk of developing depression at age 18 years. We also estimated the incidence of depression that might be attributable to peer victimisation in adolescence if this relation was causal.