ABSTRACT
A number of environmental factors have been identified which increase vulnerability to, or which precipitate, suicidal behaviour. It has been equally clear for some time that suicidal behaviour tends to aggregate within families. One plausible explanation for these observations is that environmental risk factors for suicidal behaviour, such as adverse rearing environments or childhood abuse, may be transmitted between generations. However, evidence from family, twin and adoption studies indicates that the transmission of suicidal behaviour within families is partly genetic and, to some extent, independent of the familial transmission of psychiatric disorders.
