a particular individual and various mental disorders may be explained by different models. The Vulnerability/Risk Model: According to this model, personality contributes to the onset or etiology of various common mental disorders. In other words, pre-existing personality traits either cause the development of CMDs directly or enhance the impact of causal risk factors. There is strong support for neuroticism being a robust vulnerability factor. The Pathoplasty Model: This model proposes that premorbid personality traits impact the expression, course, severity, and/or treatment response of a mental disorder. An example of this relationship would be a heightened likelihood of committing suicide in a depressed individual who also has low levels of constraint. The Common Cause Model: According to the common cause model, personality traits are predictive of CMDs because personality and psychopathology have shared genetic and environmental determinants which result in non-causal associations between the two constructs. The Spectrum Model: This model proposes that associations between personality and psychopathology are found because these two constructs both occupy a single domain or spectrum and psychopathology is simply a display of the extremes of normal personality function. Support for this model is provided by an issue of criterion overlap. For instance, two of the primary facet scales of neuroticism in the NEO-PI-R are "depression" and "anxiety". Thus the fact that diagnostic criteria for depression, anxiety, and neuroticism assess the same content increases the correlations between these domains. The Scar Model: According to the scar model, episodes of a mental disorder 'scar' an individual's personality, changing it in significant ways from premorbid functioning. An example of a scar effect would be a decrease in openness to experience following an episode of PTSD. Physical health To examine how the Big Five personality traits are related to subjective health outcomes (positive and negative mood, physical symptoms, and general health concern) and objective health conditions (chronic illness, serious illness, and physical injuries), Jasna Hudek-Knezevic and Igor Kardum conducted a study from a sample of 822 healthy volunteers (438 women and 384 men). Out of the Big Five personality traits, they found neuroticism most related to worse subjective health outcomes and optimistic control to better subjective health outcomes. When relating to objective health conditions, connections drawn were presented weak, except that neuroticism significantly predicted chronic illness, whereas optimistic control was more closely related to physical injuries caused by accident. Being highly conscientious may add as much as five years