Attempted suicide among living co-twins of twin suicide victims

OBJECTIVE: The authors hypothesized that significantly more living monozygotic than dizygotic co-twins of twin suicide victims would themselves have attempted suicide. METHOD: They determined the absence or presence of an attempt at suicide at any time among 26 living monozygotic co-twins and nine living dizygotic co-twins of twins who had committed suicide. RESULTS: They found that 10 of the 26 surviving monozygotic co-twins but none of the nine surviving dizygotic co-twins had themselves attempted suicide. CONCLUSIONS: Although monozygotic and dizygotic twins may have some differing developmental experiences, these results contribute to findings of previous studies of suicide in twins in suggesting that genetic factors may play a role in suicidal behavior.