Association between acute critical life events and the speed of onset of depressive episodes in male and female depressed patients

BACKGROUND: A series of studies indicate that a fast onset of a depressive episode (within 7 days) is a clinical variable useful for indicating bipolarity even when no manic episode has occurred to date. The role of acute critical life events as an external trigger for a fast onset of the depression is unclear so far. Therefore, aim of this investigation was to analyse the effects of acute critical life events on the speed of onset of depressive episodes. METHODS: Speed of onset of depression was assessed using the patient interview “Onset of Depression Inventory”. Acute critical life events occurring within the last 6 months before the onset of first depressive symptoms were assessed using the Munich Interview for the Assessment of Life Events and Conditions. RESULTS: 96 of 100 (96.0%) patients had at least one acute critical life event within six months prior to first symptoms of a depressive episode. 22 patients (22.0%) had a fast onset of depression (≤ 7 days). Faster onset of the current depressive episode was significantly associated with a higher number of acute minor life events (β = − 0.23; p = 0.02), but overall fast onset of a depressive episode was not significantly associated with more acute critical life events in the six months before the onset of the depression. The association between the number of acute critical life events in the half-year period preceding the onset of unipolar depressive disorders and speed of onset for the current depressive episode was neither dependent from gender nor the presence of prior depressive episodes. CONCLUSIONS: Speed of onset of depression is not strongly influenced by external trigger e.g. acute critical life events. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12888-018-1923-4) contains supplementary material, which is available to authorized users.