The most reproduced associations between suicide and personality measures are with indicators of aggression and impulsivity, which meet most, if not all, stringent endophenotype criteria (as detailed in Mann et al.14 and Kovacsics et al.28). These endophenotypes can be readily quantified using self-report data from suicide attempters and their relatives, or by psychological autopsy methods.12, 14 Impulsivity and aggression are related and many studies have also examined ‘impulsive aggression' in populations with SBs. Specifically, a number of studies have found that both impulsivity and aggression meet criteria for endophenotypes such as being heritable, associated with suicide, state independent and co-segregating with SB in families.29, 30, 31, 32, 33 The data suggesting that aggression and impulsivity are valid candidate endophenotypes of SB include case–control, retrospective (psychological autopsy), prospective longitudinal and family studies.32, 34 Laboratory assessments of impulsive aggression may be more reliable than clinical assessments, promoting the use of neuropsychological tools.14 It is a promising approach to move from personality dimensions defined at the complex level of the psychopathology derived from self or clinician reports, to more subtle traits with presumably
