A cluster analysis of symptom patterns and adjustment in Vietnam combat veterans with chronic posttraumatic stress disorder

Normal and abnormal aggression: human disorders and novel laboratory models

We review here aggression-related human psychopathologies and propose that human aggressiveness is mainly due to three major factors: (i) brain dysfunction affecting aggression-controlling brain centers (e.g. in certain types of brain lesions, epilepsy, Alzheimer disease, etc.); (ii) hypoarousal associated with chronically low plasma glucocorticoids, which foster violence by diminishing emotional barriers that limit such behaviors (e.g. in conduct disorder and antisocial personality disorder); (iii) hyperarousal which leads to irritability and outbursts (e.g. in depression, intermittent explosive disorder, chronic fatigue, etc.). Different disorders are associated with different types of aggressiveness; e.g. hypoarousal is often associated with instrumental aggression, whereas hyperarousal is associated with uncontrollable outbursts. Many psychological disorders have been simulated in laboratory models, which were used to assess aggressiveness. Little effort was invested, however, in assessing the abnormal dimension of such aggressiveness. We present here three models that appear especially suitable to assess abnormal aspects of rodent aggression: (i) abnormal attack targeting (head, throat, and belly) that is induced by hypoarousal in rats and models violence in hypoarousal-driven human aggression (ii) 'escalated' aggression (increased aggressive response due to frustration or instigation), which models irritability and hyperarousal-driven aggressiveness; and (iii) context-independent attacks induced by hypothalamic stimulation or genetic manipulations. These three models address different aspects of abnormal aggressiveness, and can become extremely useful in three areas: in evaluating and assessing models of human psychopathologies, in studying transgenic animals, and in developing new treatment strategies. Research based on these or similar models do not address aggressiveness in quantitative terms, but follows the development of abnormal aspects, and the possibilities of their specific treatment.

Clinical correlates of neurological change in posttraumatic stress disorder: an overview of critical systems

Knowledge about the biological basis of psychological trauma is changing at an exponential rate. A PsychlNFO search on the search terms "locus coeruleus" and "PTSD" revealed one peer-reviewed journal article between 1982 and 1992 and 51 in the subsequent decade. A similar search revealed zero articles on "hippocampus" and "PTSD" between 1982 and 1992 and 170 in the past decade. As clinicians, it is important to become increasingly familiar with this growing literature to use that knowledge to treat and educate patients. Imagine the relief that can be provided to survivors of trauma if clinicians can tell them that they have a good idea about what causes their symptoms and even clearer ideas about how to treat them.One ancillary but invaluable outcome to this work is the fact that understanding the neurological underpinnings of PTSD will go a long way to establishing a necessary equilibrium in nature and nurture's role in the etiology and maintenance of the disorder. In its early conceptualization, PTSD was thought by many to be an ordinary reaction to an extraordinary event, thus placing responsibility for the disorder firmly in the hands of environmental factors. A subsequent emphasis on vulnerability and resiliency factors in the disorder, however, gave the impression that genetic and potentially hard-wired neurological factors were dominant in the expression of the disorder. Appreciating the balance between nature and nurture in the development of stress disorders like PTSD will allow clinicians and patients alike to appreciate the role of personal responsibility in the process of recovery. A parallel, albeit more mature process, has occurred in the area of schizophrenia in the past four decades. Early conceptualizations of schizophrenia placed a heavy burden on parenting and behavioral factors, leaving the patients angry at their parents and parents with unnecessary guilt. The later dominance of genetic and biological theories in the disorder allayed parents of their guilt, but left both parents and patients wondering what might be done in the face of such an affliction. Modern theories of schizophrenia seem to have achieved an appropriate balance that recognizes biological vulnerabilities, but also emphasizes familial and patient responsibilities in recovery and care. In PTSD, a similar equilibrium needs to be found, and understanding the neurobiology of the disorder will go far in achieving that goal. When it is understood how trauma affects the brain and how treatment produces neurobiological changes that may remediate trauma-related effects, the patient will be in a better position to make choices about what can and cannot be done in the process of recovery. Giving patients this critical internal locus of control will provide therapeutic benefits such as confidence,self-esteem, and hope that are likely to enhance changes that occur with intervention.