chapter  7
Vulnerability Factors: Raising and Lowering the reshold for Response
Pages 16

Introduction 107 Brief History of PTSD in Combat Situations 110 reshold for a Stress Response 110 Resilience 112 Expected Stressors During Wartime 112 Preexisting Mental Health Issues as Vulnerability Factors 113 Predeployment Psychological Screening 114 In-eater Vulnerability Factors 115 Postdeployment Vulnerability Factors Related to Development of PTSD 115 Positive and Negative Trajectories 116 Treatment of Vulnerability 117 Summary 120 References 120


In Chinese philosophy, the concept of yin/yang describes the mutual relationships from a human perspective of a broad range of phenomena in the natural world. ese phenomena combine to create a unity of opposites, even when this unity occurs in constructs that may appear antithetical one to the other. e concept of yin and yang (or earth and heaven) describes two opposing and, at the same time, complementary (completing) aspects of any one phenomenon (object or process) or can be used to compare any two phenomena. ere are four laws of yin/yang:

Yin• /yang are opposing. Yin/yang describe the polar eects or impacts of phenomena. When viewing any one phenomenon (or comparing two phenomena), yin/yang describe the opposing qualities inherent in it; for example, winter and summer would be the yin/yang, respectively, of the year. Yin• /yang are mutually rooted. Yin/yang are not adversarial, but are complementary qualities in a gestalt. at is to say, the yin aspect and the yang aspect of any one phenomenon will, when put together,

form the entire phenomenon, with the combination being more than each component part. Yin/yang is a philosophy of duality. is is the reason why the Chinese term has no “and” between yin/yang-the term always expresses the two parts making up the one. In the example above, winter plus summer makes up the whole year. Yin• /yang mutually transform each other-e maximum eect of one quality will be followed by the transition toward the opposing quality. In other words, once the maximum yang aspect has manifest, such as the long days of summer, this will be followed by the transition toward the yin aspect, with the shortening of the days as winter approaches. Yin• /yang mutually wax and wane-e yin/yang aspects are in dynamic equilibrium. As one aspect declines, the other increases to an equal degree. For example, in the cycle of the year, the long days of summer gradually shorten and the nights gradually lengthen as winter approaches. roughout the process, however, the length of each day is a constant 24 hours (the equilibrium), and it is only the relative length of light and darkness that changes (the dynamic).