Life events: eﬀects and genesis 1

It is more than 40 years since a burst of studies in the late 1960s started what has become a substantial corpus of work, establishing the role of life events in psychiatric disorders (Brown & Birley, 1968; Paykel et al. 1969). Findings depended on advances in methodology. First, came development of a life events questionnaire and a scaling of their stress magnitude (Holmes & Rahe, 1967) ; then, replacement by more reliable and valid interview methods and better ways of distinguishing major and minor events (Brown & Harris, 1978; Paykel, 1996). At the start the work met entrenched opposing views – from one side that the real causes of psychiatric disorder were all constitutional, genetic and biological ; from the other side that they lay in deeper, psychodynamic conflicts, originating in infancy and childhood. These polarizations in psychiatry have now greatly lessened. The general body of life event findings has become widely accepted. Recent stressful life events precede episodes of a variety of psychiatric disorders, particularly suicide attempts, and depression (Paykel & Cooper, 1992). The events are not very specific to disorders although there is some closer association with depression for events involving interpersonal loss, and those involving loss of self-esteem or humiliation. The effect is moderate in magnitude but varies with disorder – less in schizophrenia than depression, probably less in bipolar affective disorder than unipolar; within unipolar depression stronger in first episodes and milder disorders than in severe recurrent disorders. Effects are strongest near the onset of the disorder, and decay over time, with most of the effect occurring within 6 months to a year. In this issue of Psychological Medicine we report six studies of life events. They use a variety of approaches to answer a number of questions. Four papers, each using a different approach, involve depression, the disorder that has received most study. Rahman et al. (2003) extend to a rural community in Pakistan, questions regarding post-natal depression that have been examined in Western affluent populations. They find high prevalence of depression both 6 weeks before delivery and around 3 months post-natally, and strong associations with severe events and difficulties in the previous year. These findings are similar to those obtained in the Western world (Paykel et al. 1980; O’Hara, 1986). In this much more deprived population the events reported by women were also mainly similar, with marital and family problems looming large, although events involving economic hardships such as loss of job by the breadwinner and financial difficulties were also prominent, as might be expected. This kind of life event case–control study has a long history and continues to appear. In another recent paper Brilman & Ormel (2001) used a nested case–control design in a large community survey of elderly people, and found a strong effect for severe life events on depressive episodes, particularly first episodes. Rubenowitz et al. (2001) used a case–control approach with informant interview to show effects of familial problems and family discord on suicide. Maciejewski et al. (2001) in a community survey found women more likely than men to experience an episode of depression after a major event. However, such studies are now mainly replicatory. Farmer & McGuffin (2003), a distinguished husband and wife pair who have made notable contributions to psychiatric genetics, adopt a sib-pair approach to study issues arising directly from the work of George Brown on the qualities of events which are important. Siblings share some of both the social background and genetic load of the probands. Farmer & McGuffin find depressives more likely to have experienced a severe threatening event, loss event or humiliation