The type of childhood adverse event appears important, with most studies indicating a robust interaction between 5-HTTLPR genotype and early sexual abuse, but not other types of childhood maltreatment, in the development of adult depression.17, 31, 32 These observations suggest that different types of stressors and life events may act via differential biological pathways. However, less attention has been paid to the categorisation of recent life events, although the marginal association seen in the largest meta-analysis16 and the results of several individual studies reporting an interaction between recent life events and 5-HTTLPR33, 34, 35, 36 point to an aetiological role of this interaction in the development of depression. This raises the possibility that stratification according to different types of recent life events may reveal important mechanisms concerning the role of 5-HTTLPR. However, large-scale studies focusing on separating different types of recent life events are lacking. It is also noteworthy that a study found that recent life events specifically related to financial hardships interact with neural nitric oxide synthase polymorphisms in the development of depression, indicating a prominent role for this
