The thesis seeks a theoretical understanding of depression as a problem related to social environmental conditions. This is achieved through a complex adaptive systems view combined with insights from evolutionary social psychology. Furthermore, the new found insights derived from this theoretical integration is related to conditions of the modern labour market as a means for understanding the current increase in cases of depression.
Insights from evolutionary social psychology consists of three distinct evo- lutionary explanations of depression. The first views depression as being adaptive, the second views depression as related to an inherited diathesis, and the third views depression as a maladaptive expression of functional positive affect control systems. These are discussed, related to the complex adaptive systems view and insights from modern stress research. Follow- ing this discussion, the insights are combined in formulating depression as a problem related to social environmental conditions.
The thesis concludes that depression is related to the activation of defen- sive strategies that evolved in pre-human times. When activated under unprosperous or stressful conditions, these normally adaptive strategies can come to operate outside their adaptive range, causing depression. It is further concluded that conditions of the modern labour market have the potential to cause such unprosperous and stressful conditions, thus contributing to the current increase in cases of depression.