Abnormality in glutamine-glutamate cycle in the cerebrospinal fluid of cognitively intact elderly individuals with major depressive disorder: a 3-year follow-up study.

Major depressive disorder (MDD), common in the elderly, is a risk factor for dementia. Abnormalities in glutamatergic neurotransmission via the N-methyl-D-aspartate receptor (NMDA-R) have a key role in the pathophysiology of depression. This study examined whether depression was associated with cerebrospinal fluid (CSF) levels of NMDA-R neurotransmission-associated amino acids in cognitively intact elderly individuals with MDD and age- and gender-matched healthy controls. CSF was obtained from 47 volunteers (MDD group, N=28; age- and gender-matched comparison group, N=19) at baseline and 3-year follow-up (MDD group, N=19; comparison group, N=17). CSF levels of glutamine, glutamate, glycine, L-serine and D-serine were measured by high-performance liquid chromatography. CSF levels of amino acids did not differ across MDD and comparison groups. However, the ratio of glutamine to glutamate was significantly higher at baseline in subjects with MDD than in controls. The ratio decreased in individuals with MDD over the 3-year follow-up, and this decrease correlated with a decrease in the severity of depression. No correlations between absolute amino-acid levels and clinical variables were observed, nor were correlations between amino acids and other biomarkers (for example, amyloid-ß42, amyloid-ß40, and total and phosphorylated tau protein) detected. These results suggest that abnormalities in the glutamine-glutamate cycle in the communication between glia and neurons may have a role in the pathophysiology of depression in the elderly. Furthermore, the glutamine/glutamate ratio in CSF may be a state biomarker for depression.

Decreased hippocampal N-acetylaspartate in the absence of atrophy in posttraumatic stress disorder.

BACKGROUND: Previous magnetic resonance imaging studies of posttraumatic stress disorder reported hippocampal volume loss. The goals of this study were 1) to determine the relationship between hippocampal atrophy and posttraumatic stress disorder in the absence of alcohol abuse, and 2) to test if loss of N-acetylaspartate (a neuron marker) in the hippocampus of posttraumatic stress disorder occurs separate from atrophy. In addition, volume changes in the entorhinal cortex were also explored. METHODS: Eighteen male patients with combat-related posttraumatic stress disorder (mean age 51.2 +/- 2.5 years) and 19 male control subjects (mean age 51.8 +/- 3.2 years) were studied using magnetic resonance imaging and Proton magnetic resonance spectroscopic imaging. Both groups had no alcohol and drug abuse during the past 5 years. RESULTS: Posttraumatic stress disorder and control subjects had similar volumes of hippocampus and entorhinal cortex. In contrast to volume, N-acetylaspartate was significantly reduced by about 23% bilaterally in the hippocampus of posttraumatic stress disorder when compared with control subjects, and creatine-containing compounds were reduced by 26% in the right hippocampus of posttraumatic stress disorder. CONCLUSIONS: N-acetyl asparate and creatine reductions imply that there are hippocampal abnormalities in posttraumatic stress disorder. Furthermore, these metabolite changes seem to be better indicators of posttraumatic stress disorder pathology than volume losses.

Asthenia--does it exist in space?

OBJECTIVE: First popularized as neurasthenia in the late 1800s by American George Beard, asthenia has been viewed by Russian psychologists and flight surgeons as a major problem that affects cosmonauts participating in long-duration space missions. However, there is some controversy about whether this syndrome exists in space; this controversy is attributable in part to the fact that it is not recognized in the current American psychiatric diagnostic system. METHODS: To address this issue empirically, we retrospectively examined the data from our 4 1/2-year, NASA-funded study of crew member and mission control interactions during the Shuttle/Mir space program. Three of the authors identified eight items of stage 1 asthenia from one of our measures, the Profile of Mood States (POMS). Scores on these items from 13 Russian and American crew members were compared with scores derived from the opinions of six Russian space experts. RESULTS: Crew members' scores in space were significantly lower than the experts' scores on seven of the eight items, and they generally were in the "not at all" to "a little" range of the item scales. There were no differences in mean scores before and after launch or across the four quarters of the missions. There were no differences in response between Russian and American crew members. CONCLUSIONS: We could not demonstrate the presence of asthenia in space as operationally defined using the POMS. However, the POMS addresses only emotional and not physiological aspects of the syndrome, and the subject responses in our study generally were skewed toward the positive end of the scales. Further research on this syndrome needs to be done and should include physiological measures and measures that are specific to asthenia.

Human interactions in space: results from Shuttle/Mir.

BACKGROUND: Anecdotal reports from space and results from simulation studies on Earth have suggested that space crewmembers may experience decrements in their interpersonal environment over time and may displace tension and dysphoria to mission control personnel. METHODS: To evaluate these issues, we studied 5 American astronauts, 8 Russian cosmonauts, and 42 American and 16 Russian mission control personnel who participated in the Shuttle/Mir space program. Subjects completed questions from subscales of the Profile of Mood States, the Group Environment Scale, and the Work Environment Scale on a weekly basis before, during, and after the missions. RESULTS: Among the crewmembers, there was little evidence for significant time effects based on triphasic (U-shaped) or linear models for the 21 subscales tested, although the presence of an initial novelty effect that declined over time was found in three subscales for the astronauts. Compared with work groups on Earth, the crewmembers reported less dysphoria and perceived their crew environment as more constraining, cohesive, and guided by leadership. There was no change in ratings of mood and interpersonal environment before, during, and after the missions. CONCLUSIONS: There was little support for the presence of a moderate to strong time effect that influenced the space crews. Crewmembers perceived their work environment differently from people on Earth, and they demonstrated equanimity in mood and group perceptions, both in space and on the ground. Grant numbers: NAS9-19411.

Fluvoxamine and sleep disturbances in posttraumatic stress disorder.

This study assesses the efficacy of fluvoxamine treatment on different domains of subjective sleep quality in Vietnam combat veterans with chronic posttraumatic stress disorder (PTSD). Medically healthy male Vietnam theater combat veterans (N = 21) completed a 10-week open label trial. Fluvoxamine treatment led to improvements in PTSD symptoms and all domains of subjective sleep quality. The largest effect was for dreams linked to the traumatic experience in combat. In contrast, generic unpleasant dreams showed only a modest response to treatment. Sleep maintenance insomnia and the item "troubled sleep" showed a large treatment response, whereas sleep onset insomnia improved less substantially. These therapeutic benefits contrast with published reports that have found activating effects of Selective Serotonin Reuptake Inhibitors on the sleep electroencephalogram.

The Peritraumatic Distress Inventory: a proposed measure of PTSD criterion A2.

OBJECTIVE: Meeting criterion A2 for the diagnosis of posttraumatic stress disorder (PTSD) in DSM-IV requires that an individual have high levels of distress during or after the traumatic event. Because of the paucity of valid and reliable instruments for assessing such responses, the authors developed a 13-item self-report measure, the Peritraumatic Distress Inventory, to obtain a quantitative measure of the level of distress experienced during and immediately after a traumatic event. METHOD: The cross-sectional study group comprised 702 police officers and 301 matched nonpolice comparison subjects varying in ethnicity and gender who were exposed to a wide range of critical incidents. RESULTS: The Peritraumatic Distress Inventory was found to be internally consistent, with good test-retest reliability and good convergent and divergent validity. Even after controlling for peritraumatic dissociation and for general psychopathology, the authors found that Peritraumatic Distress Inventory scores correlated with two measures of posttraumatic stress symptoms. CONCLUSIONS: The Peritraumatic Distress Inventory holds promise as a measure of PTSD criterion A2. Future studies should prospectively examine the ability of the Peritraumatic Distress Inventory to predict PTSD and its associated biological and cognitive correlates in other trauma-exposed groups.

Effects of gender and ethnicity on duty-related posttraumatic stress symptoms among urban police officers.

We studied 655 urban police officers (21% female, 48% white, 24% black, and 28% Hispanic) to assess ethnic and gender differences in duty-related symptoms of posttraumatic stress disorder (PTSD). We obtained self-report measures of: a) PTSD symptoms, b) peritraumatic dissociation, c) exposure to duty-related critical incidents, d) general psychiatric symptoms, e) response bias due to social desirability, and f) demographic variables. We found that self-identified Hispanic-American officers evidenced greater PTSD symptoms than both self-identified European-American and self-identified African-American officers. These effects were small in size but they persisted even after controlling for differences in other relevant variables. Contrary to expectation, we found no gender differences in PTSD symptoms. Our findings are of note because: a) they replicate a previous finding of greater PTSD among Hispanic-American military personnel and b) they fail to replicate the well-established finding of greater PTSD symptoms among civilian women.

Crewmember and ground personnel interactions over time during Shuttle/Mir space missions.

BACKGROUND: Anecdotal reports from space and results from simulation studies on Earth have suggested that space crewmembers may experience decrements in their mood and interpersonal environment during the 2nd half of the mission and that negative emotions may be displaced to outside monitoring personnel. METHODS: To evaluate these issues, we studied 5 American astronauts, 8 Russian cosmonauts, and 42 American and 16 Russian mission control personnel who participated in the Shuttle/Mir space program. Subjects completed questions from the Profile of Mood States, the Group Environment Scale (GES), and the Work Environment Scale (WES) on a weekly basis during the missions. Subscale scores from these measures were analyzed using a piecewise linear regression approach that analyzed normally distributed subscales using a mixed model and non-normally distributed subscales by dichotomizing the variables and using a generalized estimating equation. RESULTS: After protecting against possible Type I errors due to multiple significance tests, only weak support was found for the biphasic model: the only significant findings in favor of the hypothesized 2nd half decrements in the interpersonal environment were in crewmember GES Leader Support and astronaut WES Work Pressure. Strongly consistent confirmation was found on all six tested measures for the hypothesized displacement of tension and dysphoria from crewmembers to mission control personnel. The hypothesized displacement of tension and dysphoria from mission control personnel to management was found on five of the six tested measures. CONCLUSIONS: The absence of moderate to strong support for the biphasic model suggests that crewmember interpersonal functioning does not depend appreciably on 1st half/2nd half time effects. The consistent support found for the displacement of tension and dysphoria suggests that countermeasures need to be developed to deal with this phenomenon in both crewmembers and mission control personnel.

Posttraumatic stress disorder, trauma exposure, and the current health of Canadian bus drivers.

OBJECTIVE: Previous studies of veterans have linked posttraumatic stress disorder (PTSD) after combat-related trauma to increased reports of health problems. It is unclear whether this association between PTSD and increased health problems generalizes to civilians who are exposed to a broader array of traumatic events. We also do not know whether trauma exposure is associated with increased health problems in individuals who do not develop PTSD. Using a non-treatment-seeking civilian sample, we examined whether lifetime PTSD or trauma exposure by itself was associated with current health problems. METHODS: Using a cross-sectional design and self-report measures, we evaluated urban Canadian bus drivers (n = 342) on trauma exposure, lifetime PTSD, and current health problems. Based on their responses, we divided our sample into individuals who had never experienced trauma (n = 91), trauma-exposed individuals who had never developed PTSD (n = 218), and persons who developed PTSD at some point after trauma (n = 33). We compared these groups on health problems, treatment service use, and health assessment measures. RESULTS: The PTSD group reported increased health complaints, more frequent use of health treatments, and poorer health self-ratings compared with the exposed non-PTSD and nonexposed groups. Trauma-exposed drivers without PTSD did not differ from unexposed drivers on any health measure. Controlling for sex and trauma frequency did not alter our findings. CONCLUSIONS: Trauma exposure that leads to PTSD is associated with increased health problems, while trauma exposure alone is not. Our results extend previous findings to a broader civilian context and clarify associations between trauma exposure and health.

Psychosocial issues in space: results from Shuttle/Mir.

Important psychosocial issues involving tension, cohesion, leader support, and displacement of negative emotions were evaluated in a 4 1/2-year study involving five U.S. and four Russian Shuttle/Mir space missions. Weekly mood and group climate questionnaires were completed by five U.S. astronauts, eight Russian cosmonauts, and 42 U.S. and 16 Russian mission control subjects. There were few findings that supported our hypothesized changes in tension, cohesion, and leader support in crew and ground subjects using various time models, although crewmembers reported decreasing leader support in the 2nd half of the missions, and astronauts showed some evidence of a novelty effect in the first few weeks. There was no evidence suggesting a 3rd quarter effect among crewmembers on any of the 21 subscales evaluated. In contrast, there was strong evidence to support the hypothesized displacement of tension and negative emotions from crewmembers to mission control personnel and from mission control personnel to management. There were several significant differences in response between Americans vs. Russians, crewmembers vs. mission control personnel, and subjects in this study vs. people in comparable groups on Earth. Subject responses before, during, and after the missions were similar, and we did not find evidence for asthenia in space. Critical incidents that were reported generally dealt with events on-board the Mir and interpersonal conflicts, although most of the responses were from a relatively small number of subjects. Our findings have implications for future training and lead to a number of countermeasures.

Human interactions during Shuttle/Mir space missions.

To improve the interpersonal climate of crewmembers involved with long-duration space missions, it is important to understand the factors affecting their interactions with each other and with members of mission control. This paper will present findings from a recently completed NASA-funded study during the Shuttle/Mir program which evaluated in-group/out-group displacement of negative emotions; changes in tension, cohesion, and leader support over time; and cultural differences. In-flight data were collected from 5 astronauts, 8 cosmonauts, and 42 American and 16 Russian mission control personnel who signed informed consent. Subjects completed a weekly questionnaire that assessed their mood and perception of their work group's interpersonal climate using questions from well-known, standardized measures (Profile of Mood States, Group and Work Environment Scales) and a critical incident log. There was strong evidence for the displacement of tension and dysphoric emotions from crewmembers to mission control personnel and from mission control personnel to management. There was a perceived decrease in commander support during the 2nd half of the missions, and for American crewmembers a novelty effect was found on several subscales during the first few months on-orbit. There were a number of differences between American and Russian responses which suggested that the former were less happy with their interpersonal environment than the latter. Mission control personnel reported more tension and dysphoria than crewmembers, although both groups scored better than other work groups on Earth. Nearly all reported critical incidents came from ground subjects, with Americans and Russians showing important differences in response frequencies.

Interpersonal and cultural issues involving crews and ground personnel during Shuttle/Mir space missions.

BACKGROUND: Anecdotal reports from space and results from simulation studies on Earth suggest that interpersonal and cultural issues will have an impact on the interactions of crewmembers and mission control personnel during future long-duration space missions. METHODS: To evaluate this impact we studied 5 astronauts, 8 cosmonauts, and 42 American and 16 Russian mission control personnel who participated in the Shuttle/Mir space program. Subjects completed questions from the Profile of Mood States, the Group Environment Scale, and the Work Environment Scale on a weekly basis during the missions. Subscale scores from these measures were analyzed using a two-way ANOVA to examine mean differences as a function of country (American vs. Russian), group (crewmember vs. ground personnel), and their interaction. RESULTS: Americans scored higher on measures of vigor and work pressure, and Russians scored higher on measures of managerial control, task orientation, physical comfort, self discovery, and leader support (which also showed a significant interaction effect). Mission control subjects scored higher than crewmembers on four measures of dysphoric emotions, but both groups scored significantly lower than published norms from other studies. There were significant interaction effects for subscales measuring leader support, expressiveness, and independence, with the American astronauts scoring the lowest of all comparison groups on all three subscales. CONCLUSIONS: In future long-duration space missions, countermeasures should focus on providing support for crewmembers from a culture in the minority, and crews should include more than one representative from this culture. Positive aspects of the interpersonal environment should be enhanced. The needs of mission control personnel should be addressed as well as those of crewmembers.

Social and cultural issues during Shuttle/Mir space missions.

A number of interpersonal issues relevant to manned space missions have been identified from the literature. These include crew tension, cohesion, leadership, language and cultural factors, and displacement. Ground-based studies by others and us have clarified some of the parameters of these issues and have indicated ways in which they could be studied during actual space missions. In this paper, we summarize some of our findings related to social and cultural issues from a NASA-funded study conducted during several Shuttle/Mir space missions. We used standardized mood and group climate measures that were completed on a weekly basis by American and Russian crew and mission control subjects who participated in these missions. Our results indicated that American subjects reported more dissatisfaction with their interpersonal environment than their Russian counterparts, especially American astronauts. Mission control personnel were more dysphoric than crewmembers, but both groups were significantly less dysphoric than other work groups on Earth. Countermeasures based on our findings are discussed which can be applied to future multicultural space missions.

An overview of the Peritraumatic Distress Scale.

Posttraumatic stress disorder (PTSD) occurs when significant intrusion, avoidance, and hyperarousal symptoms are manifest for at least 1 month following exposure to a traumatic event, with at least 1 month following exposure to a traumatic event, with at least 1 month elapsed betwenn the event and the diagnossis (Diagnostic and Statistical Manual of Mental Disorders, 4th edition, 1994 [DSM-IV]).(1) However, such symptoms are not necessarily manifest in the immediate aftermath of the trauman,(2) nor does their intial presence strongly predict who will develop PTSD.(3) One immediate response to trauma which has been convicingly linked to PTSD symptoms is peritraumatic dissociation.(4) In this poster, we briefly introduce a new scale assessing immediate responses distinct from peritraumatic dissociation, and we examine its power to predict PTSD symptoms.

Sleep patterns of sheltered battered women.

PURPOSE: To describe sheltered battered women's sleep patterns and resulting daytime fatigue. The model for symptom management framed this study to describe one component of the model--symptom experience. Beginning evidence suggests that sheltered battered women experience disturbed sleep and fatigue that can interfere with vital activities. DESIGN: Descriptive using a convenience sample of 50 ethnically diverse women residing at least 21 days in battered women's shelters located in one western U.S. city. The study was done in 1997. METHODS: The Pittsburgh Sleep Quality Index (PSQI), the Mini Motionlogger Actigraph, a sleep diary, the Visual Analogue Scale for Fatigue, and an open-ended interview were used to collect data. Descriptive and inferential statistics were used to analyze the quantitative data. Qualitative data were analyzed to determine patterns and themes. FINDINGS: Seventy percent of the women had global PSQI scores of greater than five indicating poor sleep and 17 (34%) had a sleep efficiency index of 80% or less. Fourteen (28%) of the women went to bed very fatigued (> 66 mm) and 20 (40%) woke up very fatigued (> 33 mm). CONCLUSIONS: The majority of sheltered battered women experienced disturbed sleep and daytime fatigue. Both personal and environmental variables were found to significantly affect sleep patterns. Sheltered battered women can benefit from information about sleep disturbances and sleep enhancing self-care strategies.

Longitudinal course and predictors of continuing distress following critical incident exposure in emergency services personnel.

This study examines the longitudinal course and predictors of stress-specific and general symptomatic distress in emergency services personnel. A three-group quasi-experimental design was used to determine the responses of 322 rescue workers to the Loma Prieta earthquake Interstate 880 Freeway collapse and to unrelated control critical incidents. Self-report questionnaires, including measures of incident exposure, peritraumatic dissociation and emotional distress, and current symptoms, were administered 1.9 years (initial) and 3.5 years (follow-up) after the freeway collapse. Despite modest symptom improvement at follow-up, rescue workers were at risk for chronic symptomatic distress after critical incident exposure. Peritraumatic dissociation accounted for significant increments in current posttraumatic stress disorder symptoms, over and above exposure, adjustment, years of experience, locus of control, social support, and general dissociative tendencies. The results suggest that rescue workers, particularly those with more catastrophic exposure and those prone to dissociate at the time of the critical incident, are at risk for chronic symptomatic distress.

Sensory gating in chronic posttraumatic stress disorder: reduced auditory P50 suppression in combat veterans.

BACKGROUND: Posttraumatic stress disorder (PTSD) may be associated with a general impairment of cognitive function that extends beyond the processing of trauma-specific stimuli. Suppression of the auditory P50 response to repeated stimuli occurs in normal subjects and reflects the central nervous system's ability to screen out repetitive stimuli, a phenomenon referred to as sensory gating. This study examines P50 sensory gating to nonstartle auditory stimuli in PTSD subjects and normal controls. METHODS: P50 generation and gating were studied using a conditioning/testing paradigm in 15 male subjects with PTSD and 12 male controls. P50 test/conditioning (T/C) ratios were estimated using the Singular Value Decomposition method. RESULTS: The amplitude of the P50 response to the conditioning stimulus did not differ in subjects with PTSD compared to normal controls. The P50 T/C ratio is increased in PTSD subjects (mean = .408, SD = .275) as compared to the controls (mean = .213, SD = .126, two tailed t, p = .024). CONCLUSIONS: This study provides evidence that PTSD is associated with impaired gating to nonstartle trauma-neutral auditory stimuli.

Sleep disturbances in the Vietnam generation: findings from a nationally representative sample of male Vietnam veterans.

OBJECTIVE: This study analyzed questionnaire items that address complaints about sleep from the National Vietnam Veterans Readjustment Study, a nationally representative sample of the 3.1 million men and women who served in Vietnam. This study compared the frequency of nightmares and difficulties with sleep onset and sleep maintenance in male Vietnam theater veterans with male Vietnam era veteran and male civilian comparison subjects. It focused on the role of combat exposure, nonsleep posttraumatic stress disorder (PTSD) symptoms, comorbid psychiatric and medical disorder, and substance abuse in accounting for different domains of sleep disturbance. METHOD: The authors undertook an archival analysis of the National Vietnam Veterans Readjustment Study database using correlations and linear statistical models. RESULTS: Frequent nightmares were found exclusively in subjects diagnosed with current PTSD at the time of the survey (15.0%). In the sample of veterans who served in Vietnam (N = 1,167), combat exposure was strongly correlated with frequency of nightmares, moderately correlated with sleep onset insomnia, and weakly correlated with disrupted sleep maintenance. A hierarchical multiple regression analysis showed that in Vietnam theater veterans, 57% of the variance in the frequency of nightmares was accounted for by war zone exposure and non-sleep-related PTSD symptoms. Alcohol abuse, chronic medical illnesses, panic disorder, major depression, and mania did not predict the frequency of nightmares after control for nonsleep PTSD symptoms. CONCLUSIONS: Frequent nightmares appear to be virtually specific for PTSD. The nightmare is the domain of sleep disturbance most related to exposure to war zone traumatic stress.

Debriefing of American Red Cross personnel: pilot study on participants' evaluations and case examples from the 1994 Los Angeles earthquake relief operation.

The Multiple Stressor Debriefing (MSD) model was used to debrief 112 American Red Cross workers individually or in groups after their participation in the 1994 Los Angeles earthquake relief effort. Two composite case examples are presented that illustrate individual and group debriefings using the MSD model. A questionnaire which evaluated workers' experience of debriefing, was completed by 95 workers. Results indicated that workers evaluated the debriefings in which they participated positively. In addition, as participant to facilitator ratio increased, workers shared less of their feelings and reactions about the disaster relief operation. These findings, as well as more specific issues about debriefing, are discussed.

Posttraumatic stress disorder and functioning and quality of life outcomes in a nationally representative sample of male Vietnam veterans.

OBJECTIVE: Although posttraumatic stress disorder (PTSD) is a highly prevalent and often chronic condition, the relationship between PTSD and functioning and quality of life remains incompletely understood. METHOD: The authors undertook an archival analysis of data from the National Vietnam Veterans Readjustment Study. The study subjects consisted of the nationally representative sample of male Vietnam veterans who participated in the National Vietnam Veterans Readjustment Study. The authors estimated PTSD at the time of the interview with the Mississippi Scale for Combat-Related Posttraumatic Stress Disorder. They examined the following outcomes: diminished well-being, physical limitations, bed day in the past 2 weeks, compromised physical health status, currently not working, and perpetration of violence. Logistic models were used to determine the association between PTSD and outcome; adjustment was made for demographic characteristics and comorbid psychiatric and other medical conditions. RESULTS: The risks of poorer outcome were significantly higher in subjects with PTSD than in subjects without PTSD in five of the six domains. For the outcome domains of physical limitations, not working, compromised physical health, and diminished well-being, these significantly higher risks persisted even in the most conservative logistic models that removed the shared effects of comorbid psychiatric and other medical disorders. CONCLUSIONS: The suffering associated with combat related-PTSD extends beyond the signs and symptoms of the disorder to broader areas of functional and social morbidity. The significantly higher risk of impaired functioning and diminished quality of life uniquely attributable to PTSD suggests that PTSD may well be the core problem in this group of difficult to treat and multiply afflicted patients.