TABLE 3.

Associations Between Confounding Variables and Childhood Trauma in a Twin Cohort (N=2,127)

Confounding Variable	Lifetime Childhood Trauma
	Maltreatment by an Adult		Bullying by Peers				Accidents
			Mothers’ Reports		Children’s Self-Reports
	Relative Risk	95% CI	Relative Risk	95% CI	Relative Risk	95% CI	Relative Risk	95% CI
Individual and socioeconomic factors
Male	1.49	0.95–2.32	1.25	1.04–1.51	1.16	0.88–1.53	0.93	0.79–1.09
Socioeconomic deprivation	3.81	2.11–6.88	1.83	1.45–2.31	2.10	1.49–2.97	1.06	0.87–1.30
IQ	0.97	0.96–0.98	0.99	0.98–1.00	0.98	0.97–0.99	1.00	0.99–1.01
Children’s psychopathology
Internalizing problems	1.04	1.03–1.06	1.02	1.02–1.03	1.02	1.00–1.03	1.01	0.99–1.01
Externalizing problems	1.04	1.03–1.05	1.02	1.02–1.03	1.02	1.01–1.02	1.01	1.00–1.01
Genetic vulnerabilities
Mothers with psychosis syndrome	4.58	2.76–7.61	2.24	1.75–2.88	1.94	1.21–3.11	1.32	0.98–1.77
Genetic composite riska
Low	1.44	0.90–2.31	1.09	0.90–1.33	1.12	0.83–1.50	1.11	0.94–1.30
High	2.97	1.34–6.57	1.57	1.07–2.29	2.69	1.63–4.44	1.50	1.07–2.09
Highest	3.77	1.78–8.01	1.67	1.14–2.43	3.59	2.40–5.37	0.96	0.62–1.48

^aThe target twin’s genetic risk was coded as “low” when the dizygotic co-twin did not report any definite psychotic symptoms; “high” when the dizygotic co-twin reported at least one definite symptom; and “highest” when the monozygotic co-twin reported at least one definite symptom. All groups were compared with the group that had the “lowest” genetic risk, that is, when the target twin’s monozygotic co-twin did not report any psychotic symptoms.