Differentiation of depression and PTSD symptoms in combat veterans

Psychotic-like experiences, symptom expression, and cognitive performance in combat veterans with posttraumatic stress disorder

Apparent psychotic symptoms are often associated with posttraumatic stress disorder (PTSD), but these symptoms are poorly understood. In a sample of 30 male Vietnam combat veterans with severe and chronic PTSD, we conducted detailed assessments of psychotic symptom endorsement, insight, symptom severity, neurocognitive function, and feigning. Two thirds of the subjects endorsed a psychotic item but did not believe that the experiences were real. Those endorsing psychotic items were higher in PTSD severity, general psychopathology, and dissociation but not depression, functional health, cognitive function, or feigned effort. Severity of psychotic symptoms correlated with dissociation, combat exposure, and attention but not PTSD, depression, or functional health. Those endorsing psychotic items scored higher on a screen but not on a detailed structured interview for malingering. Endorsement of psychotic experiences by combat veterans with PTSD do not seem to reflect psychotic symptoms or outright malingering.

The structure of posttraumatic psychopathology in veterans attending primary care

This study attempted to extend research indicating that posttraumatic stress disorder (PTSD) factors of Re-experiencing, Avoidance and Hyperarousal are more related to Fear/phobic disorders, while PTSD Dysphoria is more related to Anxious-Misery disorders. Trauma exposure, PTSD and comorbidity data for 668 veteran patients were analysed using confirmatory factor analyses and relative strengths of the relationships between PTSD factors and the Fear and Anxious-Misery factors were assessed. Combining Simms, Watson, and Doebbeling's (2002) model of PTSD symptoms and Krueger's (1999) Fear/Anxious Misery model of mood and anxiety disorders fit the data well. Contrary to previous research, PTSD Re-experiencing, Avoidance and Hyperarousal did not correlate more with the Fear factor; nor did PTSD Dysphoria correlate more with Anxious-Misery. Hyperarousal was more closely related to Fear than was Re-experiencing; however, Avoidance was not. Dysphoria was more closely related to the Anxious-Misery factor than all other PTSD factors.

Testing whether posttraumatic stress disorder and major depressive disorder are similar or unique constructs

Posttraumatic stress disorder (PTSD) and major depressive disorder (MDD) co-occur frequently, are highly correlated, and share three symptoms in common. In the present paper, the authors tested whether PTSD and MDD are similar or unique constructs by examining their symptoms using Rasch modeling. Data were used from the 766 trauma-exposed subjects in the National Comorbidity Survey-Replication (conducted in the early 2000s) with PTSD and MDD symptom ratings. Results demonstrate that MDD symptoms were less frequently endorsed than PTSD symptoms-even for the three symptoms shared between the disorders. PTSD and MDD items represented a single, underlying dimension, although modest support was found for a secondary sub-factor. Removing their shared symptoms, and additional depression-related dysphoria symptoms, continued to result in a single underlying PTSD-MDD symptom dimension. Results raise further questions about PTSD's distinctiveness from MDD, and the causes of their comorbidity.

Behavioral inhibition and activation in posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) is characterized by anxiety symptoms and impulsivity and aggression, which are thought to represent examples of excessive behavioral inhibition and activation, respectively. PTSD and traumatized control subjects performed the Stop-Signal Task to assess behavioral activation and inhibition simultaneously. PTSD subjects showed no evidence of the generally increased behavioral inhibition expected to accompany anxiety, but exhibited progressively decreased behavioral activation during acquisition of the task. However, when behavior was facilitated using monetary rewards, both PTSD and traumatized control subjects showed increases in behavioral activation, whereas PTSD subjects also showed significant disinhibition. These findings argue against PTSD patients being chronically inhibited and unresponsive to rewards, and the presence of disinhibition accompanying behavioral activation in these subjects may explain the impulsivity and aggression associated with PTSD.