“How all occasions turn against me” is a phrase from Act IIII, Scene IIII of William Shakespeare's Hamlet. This sentence, spoken by Hamlet, expresses his emotional state as he is currently distraught over 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 soon after discovers that Claudius murdered his father to become king, and he takes it upon himself to avenge his father's death. Throughout the play, the intense stress of the situation seems to take its toll on Hamlet, putting him into a depressive state, and eventually, over time, he goes "mad." To put it in psychological terms, he developed psychosis. The question addressed in this article is how does an individual develop psychosis? There is a wide range of theories, all based on reasonable evidence. These different theories seem to indicate that psychosis is the result of a recipe of different environmental, biological and neuronal 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, titled Reassessment of the interaction between psychosis and depression symptoms in the pathogenesis of psychotic syndromes: results from a twenty-year prospective community study, examines the relationship between psychosis and depressive symptoms at psychosis onset, using data from the Zurich study (Rossler, et al., 2011, pp. 11-13). The 20-year study, conducted in Switzerland, involved...... middle of article ......n Os , J., & Myin-Germeys, I. (2011) . Childhood trauma and increased stress. ACTA PSYCHIATRICA, 28-35. Qoldman, M.B. and 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, KR and Ajdacic-Gross, V. (2011). Reassessment 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, JL, Pogue-Geile, MF and Grace, AA (2004). Developmental pathology, dopamine, and stress: a model for age of onset of schizophrenia symptoms. Schizophrenia Bulletin, 875-900.