Showing papers by "Nicholas B. Allen published in 2003"

The social risk hypothesis of depressed mood: evolutionary, psychosocial, and neurobiological perspectives.

Abstract: The authors hypothesize that depressed states evolved to minimize risk in social interactions in which individuals perceive that the ratio of their social value to others, and their social burden on others, is at a critically low level. When this ratio reaches a point where social value and social burden are approaching equivalence, the individual is in danger of exclusion from social contexts that, over the course of evolution, have been critical to fitness. Many features of depressed states can be understood in relation to mechanisms that reduce social risk in such circumstances, including (a) hyper-sensitivity to signals of social threat from others, (b) sending signals to others that reduce social risks, and (c) inhibiting risk-seeking (e.g., confident, acquisitive) behaviors. These features are discussed in terms of psychosocial and neurobiological research on depressive phenomena.

Comorbidity as a predictor of symptom change after treatment in combat-related posttraumatic stress disorder.

Abstract: Posttraumatic stress disorder (PTSD) is a difficult condition to treat, and existing studies show considerable variability in outcome. Investigations of factors that influence outcome have the potential to inform alternate treatment approaches to maximize benefits gained from interventions for the disorder. Because PTSD is commonly associated with comorbidity, it is important to investigate the influence of comorbidity on symptom change after treatment. This article examines pretreatment and 9-month follow-up data for 134 Australian Vietnam veterans who attended a treatment program for combat-related PTSD. A series of analyses were conducted to investigate the influence of the comorbid factors of anxiety, depression, anger, and alcohol use on PTSD symptom change after treatment. Analyses identified anger, alcohol, and depression as significant predictors of symptom change over time, independent of the effect of initial PTSD severity. Further analyses indicated that anger at intake was the most potent predictor of symptom change. Further investigations of anger as an influence on symptom change after treatment of combat-related PTSD is recommended.

NEO Five-Factor Inventory Scores: Psychometric Properties in a Community Sample

Abstract: Psychometric analysis of scores from the NEO Five-Factor Inventory (NEO-FFI) confirmed their internal (N = 527) and lest re test reliability (n 335) in an Australian adult sample. The data also pro...

On the nature of cardiovascular activation at an arousal from sleep.

Abstract: Study objectives The intent of the study was to explore the nature and function of the cardiovascular activation response that occurs at an arousal from sleep. Design Four experiments were conducted. The first compared the pattern of physiologic response to orienting and startle stimuli and arousal from sleep. The second and third measured the amplitude of the cardiovascular arousal response as a function of the trait of fearfulness and the threat value of the arousing stimulus, respectively. The final experiment assessed the effect of arousal duration. Setting The experiments were conducted in the sleep laboratory of the Department of Psychology, University of Melbourne. Participants A total of 42 (24 women and 18 men) healthy individuals between the ages of 18 and 24 participated in the experiments. Interventions The experiments manipulated the stimuli to which participants were exposed (orienting and startle stimuli and arousal from sleep), the threat value of stimuli used to arouse participants from sleep, and individual differences in fearfulness. Measurements and results The major dependent variables were heart rate, blood pressure, and a measure of peripheral vasoconstriction (digital pulse volume). In addition, in the first study, the galvanic skin response and orbicularis oculi electromyographic activity were measured. Experiment 1 showed that the pattern of physiologic response at an arousal from sleep differed, with a substantially larger cardiovascular component, from responses to orienting and startle stimuli. Experiments 2a and 2b indicated that the magnitude of the cardiovascular response at an arousal was unrelated to either individual differences in fearfulness or differences in the threat value of arousing stimuli. The final experiment showed that the cardiovascular response at an arousal was not a return to waking levels of activity but, rather, was a transient activation response. Conclusions The study supported the view that the cardiovascular activation response at an arousal from sleep is a transient, reflex-like response that is different from the response that occurs during normal wakefulness.

Adaptive social reasoning in depressed mood and depressive vulnerability.

Abstract: In this study we evaluate the evolutionary hypothesis that depressed states are associated with more adaptive reasoning about social risks, such as defeat or rejection. A total of 78 women were administered one of two mood inductions (depressed vs. neutral), followed by four Wason selection reasoning tasks (truth-detection, cheater-detection, and two social risk tasks addressing attachment and social competition risks). Those in the depressed mood condition gave significantly more correct responses on a task requiring participants to reason about social competition. There were no significant differences on performance for the other reasoning tasks between the two mood induction conditions. Furthermore, measures of two dimensions of depression prone personality (sociotropy and autonomy) were associated with less adaptive reasoning about social risks. These results suggest that mildly depressed states may indeed facilitate adaptive reasoning within certain domains, whereas vulnerability to depression may be associated with a relative impairment in reasoning about social risks.

MMPI-2 based subgroups of veterans with combat-related PTSD: differential patterns of symptom change after treatment.

Abstract: Considerable research has focused on the use of the MMPI to assess posttraumatic stress disorder (PTSD) through identification of mean profile configurations and the development of PTSD subscales. Little work, however, has addressed the heterogeneity of profiles evident in PTSD populations. This study investigated the MMPI-2 profiles of 158 Australian treatment-seeking Vietnam veterans with combat-related PTSD to identify distinct subgroups. Three robust subgroups were identified on the basis of their MMPI-2 profile and compared on PTSD and associated symptomatology. These subgroups consisted of a mild PTSD group with subclinical personality pathology, and two severe PTSD groups that differed in levels of personality disturbance and general psychopathology. Most notably, differences between these latter two groups occurred in the areas of externalization, alienation, and propensity for acting out. These groups were labeled as subclinical, trauma profile, and global. The groups demonstrated significant differences in the patterns of recovery after treatment. The subclinical group demonstrated little change after treatment. In contrast, the trauma profile and global groups both improved, although the trauma profile group demonstrated greater PTSD symptom reduction than the global group.

MMPI-2 as a predictor of change in PTSD symptom clusters: a further analysis of the Forbes et al. (2002) data set.

Abstract: In this study, we reanalyzed the Forbes et al. (2002) data set to examine the Minnesota Multiphasic Personality Inventory (MMPI-2; Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) as a differential predictor of change across posttraumatic stress disorder symptom clusters following treatment in 141 Vietnam veterans. A series of partial correlation and linear multivariate regression analyses, controlling for initial symptom severity, identified several scales predictive of symptom change. None of the MMPI-2 scales, however, emerged as predictors of change in reexperiencing symptoms. Social alienation and marital distress were the most potent predictors for avoidance symptoms. Anger, alcohol use, and hypomania were the most potent predictors for the hyperarousal symptoms. Of the personality disorders, borderline personality was the strongest predictor of change in the avoidance and hyperarousal clusters. Further replication of the findings of this article and those reported by Forbes et al. (2002) is required.