T1 data were assessed during the baseline assessment and covered lifetime history up to the time of the T1 assessment. We created a continuous measure of T1 suicidality with range 0–2: 0) no history of suicidal thoughts or attempt; 1) history of suicidal thoughts only; 2) history of suicide attempt (SA). The latter was assessed with the item “Have you ever tried to kill yourself?” (Preuss, Schuckit, Smith, et al., 2002). Conduct disorder symptoms were used to assess the externalizing domain (Dick, 2007; Krueger & Markon, 2006). Conduct disorder symptoms were selected to assess external symptoms in youth because they are in evidence at an early age, prior to the onset of other externalizing variables that confer risk for SA in youth assessed by the SSAGA, for example substance use disorders (Lahey, Miller, Gordon et al., 1999; Wagner & Anthony, 2002). We created a continuous variable with range 0–2: 0) no conduct disorder symptoms, 1) 1-plus symptoms but no diagnosis, 2) conduct disorder diagnosis. To assess depression we also created a continuous variable with range 0–2: 0) no history of
