Table 6.

Individual and cumulative effects of sibling and peer bullying at 12 years and depression, anxiety suicidal ideation and self-harm at 24 years.

	Sibling and peer bullying status
Outcome OR (95% CI)	Uninvolved	Either	p value	Both	p value	Linear trend	p value
Depression
N = 2,117
Unadjusted	Reference	1.50 (1.09–2.05)	0.012	1.97 (1.21–3.21)	0.006	1.43 (1.16–1.78)	0.001
Imputed adjusted	Reference	1.45 (1.05–1.99)	0.024	1.90 (1.15–3.13)	0.012	1.40 (1.12–1.75)	0.003
Anxiety
N = 2,105
Unadjusted	Reference	1.85 (1.35–2.53)	0.000	1.78 (1.05–3.01)	0.032	1.49 (1.20–1.85)	0.000
Imputed adjusted	Reference	1.73 (1.26–2.39)	0.001	1.60 (0.94–2.75)	0.085	1.41 (1.13–1.76)	0.003
Suicidal ideation
N = 2,118
Unadjusted	Reference	1.61 (1.31–1.97)	0.000	2.37 (1.69–3.33)	0.000	1.57 (1.36–1.81)	0.000
Imputed adjusted	Reference	1.54 (1.25–1.90)	0.000	2.18 (1.54–3.07)	0.000	1.50 (1.30–1.74)	0.000
Non-suicidal self-harm
N = 2,117
Unadjusted	Reference	1.36 (1.06–1.75)	0.016	1.32 (0.85–2.05)	0.211	1.23 (1.03–1.47)	0.024
Imputed adjusted	Reference	1.31 (1.01–1.69)	0.041	1.27 (0.81–1.98)	0.303	1.19 (0.99–1.44)	0.060
Suicidal self-harm
N = 2,117
Unadjusted	Reference	1.79 (1.15–2.79)	0.010	3.46 (1.92–6.25)	0.000	1.85 (1.39–2.45)	0.000
Imputed adjusted	Reference	1.77 (1.13–2.78)	0.012	3.47 (1.90–6.34)	0.000	1.84 (1.38–2.46)	0.000

OR, Odds ratio; CI, Confidence intervals.

Bold = p < 0.010 (Bonferroni correction).

Confounders included in imputed adjusted analysis: sex, birth order, maternal depression, internalizing and externalizing problems, psychiatric diagnosis, peer bullying victimization and perpetration, maltreatment, domestic violence.

Children presenting any psychiatric diagnosis at 7 years were excluded.

Non-Involved, Youth reporting no frequent* victimization or perpetration; Victims, Youth reporting frequent victimization only; Bully-Victims, Youth reporting both frequent victimization and perpetration; Bullies, Youth reporting frequent perpetration only.

*Frequent, At least once a week in the past 6 months.