Bullying victimisation in childhood and mental health in early adulthood: comparison of prospective and retrospective reports

The association between childhood bullying victimisation and mental health problems in adulthood has been consistently reported in the literature. Previous studies used both retrospective and prospective reports to measure bullying victimisation. However, there could be biases in both reports. We aimed to assess agreement between prospective and retrospective reports of childhood bullying victimisation, to compare their associations with mental health in early adulthood, and to examine the associations of consistent prospectively and retrospectively reported bullying victimisation with adult mental health. Data were from the prospective Bavarian Longitudinal Study of neonatal at-risk children and term-born controls recruited at birth. 489 participants were followed from birth to age 26 (mean [SD]: 26.4 [0.8] years). Adult mental health was assessed using both the Achenbach Young Adult Self-Report (YSR) and standardised diagnostic interviews. Childhood bullying victimisation was prospectively reported by participants and parents at age 13 and retrospectively self-reported at age 26. We showed that the agreement between retrospective and prospective self-reports of bullying victimisation was fair (Kappa 0.30) with only slight agreement (Kappa 0.18) when compared with prospective parent-reports. Both prospectively and retrospectively self-reported bullying victimisation was associated with poor mental health. Retrospective reports tended to produce stronger associations. Participants who reported being bullied both retrospectively and prospectively had a particularly elevated risk for mental health problems. In conclusion, prospective and retrospective reports capture partly different individuals with exposure to bullying victimisation. Exposure to bullying victimisation, whether it was retrospectively or prospectively self-reported, was associated with an increased risk for mental health problems.