The aim of the article is to discuss the specifics of human actions and decision-making processes from the psychopathological perspective. The concepts of action and decision making are reported in the context of human experience and the experiential structure of self-determination. The starting point is provided by considerations related to the notion of mental illness as described by Lennart Nordenfelt, as well as Antoni Kępiński’s concept of informational metabolism. The consequences of and changes to decision-making processes in mental disorders will be presented on the example of depressive experience. Decision-making process can be understood in terms of three-dimensional pre-reflexive experience that undergoes changes in depressive patients: space of possibility, sense of agency and time experience. The analysis will allow us to better understand the structure of experience attributable to people suffering from depression.