Proximal Stressors

Proximal stressful events are the presumed ‘causes’ of depression. Some, such as substance abuse (excessive intake of alcohol or drugs, both prescribed and illegal), are more influential than generally conceded.
In non-melancholic disorders, depression is much more a consequence of an interaction between an immediate stressor and the individual’s temperament and personality style. The same stressful event can evoke a wide range of responses in different people. Some may ignore it, others worry about it. Some may feel that ‘all is lost’ and others that the ability to control life has slipped away. The individual’s reaction to the stressor contributes to both the onset of the depression and its severity.
The most common causes of melancholic, psychotic and bipolar depression appear ‘biological’. In the past, melancholic depression was called ‘endogenous’ depression, meaning coming from ‘within’. It was therefore considered to be independent of stress. However, stress may precipitate a biological reaction, thus bringing on depression. (A number of medical conditions, for example diabetes, can be similarly brought on by stress in those predisposed to the disease.) As the melancholic disorders are more likely to commence from the age of 40 onwards, an ‘age effect’ on the brain must be conceded. Some external factors may be relevant for the more biological disorders. For example, in comparison to non-melancholic disorders, the onset of manic, psychotic and melancholic depressive episodes is increased in spring, indicating a seasonal cause. The rapid increase in hours of bright sunshine is thought to trigger depression and mania by affecting the pineal gland.
It does seem that the principle depressive sub-types show varying susceptibility (or resistance) to certain life stresses. This idea is developed further on the following pages.