Why are there people with psychosis and people without? Is it all due to genetic and vulnerability factors?

Schizophrenia or psychotic disorder has often been assumed as a hereditary disorder. However, recently accumulated evidence has demonstrated the importance of environmental factors, particularly social factors. Two dominant theoretical frameworks explain the association between social factors and psychosis, i.e., the social defeat (SD) hypothesis and cognitive models of psychosis. According to SD hypothesis, the common denominator of most social risk factors is the negative experience of being excluded from a majority group. According to cognitive models, psychosis occurs due to non-adaptive appraisals of anomaly experience. Recent studies suggest that these explanations complement each other. However, application of these frameworks in explaining cases in clinical setting has not been examined. In this single-case research design study, a participant diagnosed with schizophrenia from Bogor, Indonesia was interviewed for his medical history (anamneses). The psychological model of SD was used to comprehend anamneses. The root of psychotic symptoms of the participant was familial conflict, which led to his negative beliefs about himself and others. This negative view of himself and others caused the patient to experience clinical level of negative affect, which in turn developed into psychotic symptoms. To conclude, the psychological model of SD can be used to assess clients in the clinic.