The interactive effects of elevated mid-afternoon cortisol and trauma history on PTSD symptoms in children: a preliminary study.

Given the alarming frequency and severity of trauma exposure among children, identifying contextual and biologic factors that increase risk for symptomatic responses to trauma is an essential step toward preventing psychopathology. Basal functioning of the hypothalamic pituitary adrenal axis was evaluated to determine its role in relations between trauma exposure and PTSD symptoms among 66 children (M age=10.7 years). Exposure to recent trauma (within the past year), previously experienced trauma (more than 1 year ago), and basal mid-afternoon cortisol levels were each positively related to PTSD symptoms. Further, these factors interacted in an additive manner to account for a significant proportion of the variance in PTSD symptoms. Implications for the early identification of children at risk for symptomatic responses to trauma are discussed.

Relations between recurrent trauma exposure and recent life stress and salivary cortisol among children.

The present study evaluated the independent and cumulative effects of recent life stress, previous trauma, and recent trauma exposure on salivary cortisol levels among school-aged children. Sixty-eight children (mean age=10.7 years) reported their exposure to life stressors and traumatic events in the 12 months preceding the study. Children and their caregivers reported frequency of exposure to trauma earlier in life. Exposure to life stress within the past 12 months was related to higher afternoon cortisol levels. Exposure to high levels of recent trauma in combination with frequent exposure to trauma earlier in life was related to both lower morning cortisol levels and higher afternoon cortisol levels. Results suggest that frequency, duration, and severity of exposure to stress and trauma played key roles in the prediction of basal cortisol levels in a community sample of urban youth.

Advances and future directions in the study of children's neurobiological responses to trauma and violence exposure.

One of the most exciting developments to emerge from the field in the past 20 years is the increasing attention to neurobiological responses to violence and trauma exposure. Although researchers have yet to identify a consensual pattern of neurobiological response to violence and trauma exposure, it does appear that some type of alteration in the hypothalamic pituitary adrenal (HPA) axis is likely. This article briefly reviews the multiple moderating factors that help account for the divergent patterns in HPA function as well as methodological advances that will continue to improve the assessment of HPA function in youth exposed to violence and trauma.

Corticotropin-releasing factor in posttraumatic stress disorder (PTSD) with secondary psychotic symptoms, nonpsychotic PTSD, and healthy control subjects.

BACKGROUND: Recent studies have reported a high comorbidity between posttraumatic stress disorder (PTSD) and psychotic symptoms, and it has been hypothesized that PTSD with comorbid psychosis is a severe form of PTSD. Few studies have examined the neurobiology of PTSD with comorbid psychosis. If PTSD with secondary psychotic symptoms (PTSD-SP) is a severe form of PTSD, then it might be expected to show more extreme perturbations in the neuroendocrine patterns that characterize PTSD. METHODS: Patients with PTSD with secondary psychotic symptoms (PTSD-SP), PTSD without psychosis, and healthy comparison subjects were compared for differences in cerebrospinal fluid concentrations of corticotropin-releasing factor (CRF) and somatotropin-release-inhibiting hormone (SRIF). RESULTS: The PTSD-SP subjects had significantly higher mean levels of CRF than either the PTSD or control subjects (p <.01). The three groups showed similar SRIF levels. CONCLUSIONS: These data implicate abnormalities in the secretion of CRF with the production of secondary psychotic symptoms in PTSD. This finding supports the validity of PTSD-SP as a PTSD subtype and as a severe form of PTSD.

Differences in smooth pursuit eye movement between posttraumatic stress disorder with secondary psychotic symptoms and schizophrenia.

Studies show high comorbidity between post-traumatic stress disorder and psychotic symptoms. Despite this fact, there has been only one published study of the neurobiology of this enigmatic disorder. This preliminary study examines the relationship between psychotic symptoms in post-traumatic stress disorder (PTSD) and schizophrenia by measuring smooth pursuit eye movement (SPEM) in subjects with PTSD and secondary psychotic symptoms, schizophrenia, and healthy controls. The results show that PTSD with secondary psychotic symptoms is associated with a SPEM deficit that is different from the SPEM deficit associated with schizophrenia.

Parametric analysis of event-related potentials in semantic comprehension: evidence for parallel brain mechanisms.

In event-related potential (ERP) studies of cognitive processes, the electrophysiological responses are typically contrasted between experimental conditions that are taken to represent discrete categories (e.g. attended vs. unattended stimuli, or real vs. nonsense words). Because categorical variation is less powerful than continuous or parametric variation, a more effective method may be to relate continuous variation in the cognitive process with matching variation in the electrophysiological responses. We assessed continuous variation in the expectancy and meaningfulness of words in different sentence contexts by having subjects rate the words along these two dimensions. ERP averages were then created for each word by averaging the ERP across all subjects' responses to that word. A parametric principal components analysis was then conducted by multiplying the factor topographies from the temporal PCA by the parameter correlation maps for each rating parameter. This analysis showed that both expectancy and meaningfulness begin to influence lexical processing around 200 ms. Source localization of the expectancy N2 (recognition potential) pointed to a source in the left fusiform gyrus region (visual word form area). Source localization of the meaningfulness N2 (meaning recognition potential) suggested a right inferior posterior source, such as in the right cerebellum or right fusiform area. Further research with parametric analysis of dense array ERPs may clarify the multiple neural mechanisms of word recognition.