“As all occasions inform against me” is a line from Act IIII, Scene IIII of William Shakespeare's Hamlet. This line, spoken by Hamlet, expresses his emotional state as he is currently overwhelmed by the death of his father, the King of Denmark, and the situations surrounding it. After Hamlet learns of his father's death, he discovers that his mother has married Claudius, Hamlet's uncle. On top of all this, Hamlet finds out soon after that Claudius killed his father to become king, and takes it upon himself to avenge his father's death. Throughout the play, the severe stress of the situation seems to have a negative impact on Hamlet, driving him into a depressed state, and eventually over time he becomes "mad". To put it in psychological terms, he developed psychosis. The question this article will address is: How does an individual develop psychosis? There is a wide range of theories, all with reasonable evidence. These different theories seem to indicate that psychosis is the result of a combination of different environmental, biological and neural structural factors. One environmental factor that appears to play a role in the development of psychosis is stress. A study published in the journal European Archives of Psychiatry and Clinical Neuroscience entitled Reappraisal of the interplay between psychosis and depression symptoms in the pathogenesis of psychotic syndromes: results of a twenty-year prospective community study examines the relationship between psychosis and depressive symptoms in the onset of psychosis, using evidence from the Zurich study (Rossler, et al., 2011, pp. 11-13). The 20-year study, conducted in Switzerland, involved...... half of the article ......n Os, J., & Myin-Germeys, I. (2011). Childhood trauma and increased stress. ACTA PSYCHIATRICA, 28–35. Qoldman, M. B., & Mitchell, C. P. (2004). What is the functional significance of hippocampal pathology in schizophrenia? Schizophrenia Bulletin, 367-392. Rossler, W., Angst, J., Gamma, A., Haker, H., Stulz, N., Merikangas, K. R., & Ajdacic-Gross, V. (2011). Reevaluation of the interaction between psychosis and depression. Eur Arch Psychiatry Clin Neurosci, 11-19.Stefanis, NC, Henquet, C., Avramopoulos, D., Smyrnis, N., Evdokimidis, I., Germeys, IM, . . . Os, J. V. (2007). COMT Val158Met moderation of stress-induced psychosis. Psychological medicine, 1651–1656. Thompson, J. L., Pogue-Geile, M. F., & Grace, A. A. (2004). Developmental pathology, dopamine, and stress: A model for age of onset of schizophrenia symptoms. Schizophrenia Bulletin, 875-900.