Cognitive vulnerabilities provide a clear link of how individuals are exposed to the elements of the risk in hopelessness and later to the formation of recurrence and relapse in depression. It has also been associated with the negative social support and inferential styles. Therefore, it is crucial to understand how these concepts are interrelated, and defined. This paper presents a model of the dynamics of a humans developmental state in relation to the social support and negative cognitive thought formation (cognitive depressogenic thought). Theory in cognitive vulnerability is used to serve as a foundation of this model. Simulation experiments under different parameter settings pointed out that the model is able to produce related behaviour as described in several literatures. In addition, using a mathematical analysis, the equillibria of the model has been determined and analyzed.