What kind of evidence is needed?

What data could be considered as tentative evidence in favour of a causal connection between traumatic life events and depression?

If,

1. – depressions or certain types of depression were frequently preceded by life events;

2. – the events would have taken place in close temporal proximity to the onset of depression, and

3. – would have induced a marked degree of inner turmoil (stress),

4. – while relief or amelioration of the event's traumatic consequences would lead to alleviation or clearing of the depression,

a causal relationship between event and depression would seem likely. Available evidence for this is discussed in this chapter.

Definitive proof of a causal relation would be the showing that the traumatic life events had led to alterations in brain circuits considered to be associated with (certain) depressive symptoms or syndromes.

Available evidence for this is discussed in Chapter 8.

Life events preceding depression

Acute events

The frequency of life events as well as their gravity is increased prior to major depression. This is probably also true for other depression types, but empirical data are scarce (Dolan et al., 1985; Kendler et al., 1993a,b). This was shown in community studies comparing individuals meeting criteria for depression with nondepressed individuals in the general population, and in case–control studies comparing depressives under psychiatric treatment with nondepressed controls (Brown & Moran, 1994; Dohrenwend et al., 1995).