Spatially congruent negative BOLD responses to different stimuli do not summate in visual cortex.

The negative BOLD response (NBR) is a prevalent feature of brain activity during sensory and cognitive tasks. It is thought to reflect suppression or deactivation of cortical areas unrequired for task performance, but much remains to be understood regarding its response properties and generative pathways. Here we study a unique property of sensory cortex NBR that most distinguishes it from positive BOLD responses (PBR), its appearance in a single location due to different stimuli. We investigate whether such NBR are additive, as a means of studying whether stimulus driven NBR arise via a single or multiple pathways. During fMRI, subject's passively viewed separate checkerboard stimulation of the foveal and middle-eccentricity areas of the left visual field and a third condition that stimulated both areas concurrently. PBR was observed in the contralateral primary visual cortex and NBR was seen throughout the ipsilateral cortex as well as in contralateral regions superior and anterior to the PBR. Strong spatial overlap of NBRs to all three conditions was observed. We found that neither PBR nor NBR were additive. NBR amplitudes to combined stimuli were equal to those of the strongest (foveal) stimulus alone, despite the mid-eccentricity stimulus inducing substantial NBR on its own. The lack of summation of NBRs, both in the same and opposite hemispheres to the PBR, suggests that they arise from a single pathway. Our findings suggest that although individual stimuli each exert a separate inhibitory effect on non-stimulated regions, once in combination these effects operate as a binary system. Deactivation of a given visual area is driven by a single signal, representing only the largest of the contributing sources.

Implementation of a Neurotrauma Hotline for post-hospital continuity of care.

BACKGROUND: There are 4.8 million emergency department (ED) visits for traumatic brain injury (TBI) annually in the United States. Many of these patients do not receive educational information or follow-up care. AIMS OF THE STUDY: Our institution implemented a Neurotrauma Hotline for TBI patients. This study describes our implementation and utilization of a Neurotrauma Hotline at a Level I trauma center. METHODS: Callers and outcomes of calls to the hotline over a 12-month period were analyzed. Correlation analysis was done to assess relationship between hotline calls and TBI clinic volumes. RESULTS: There were 1205 calls to the hotline. Calls were most commonly from internal providers or patients, with 338 repeat callers. The call reason was frequently an appointment (36.8%) or advice (32.1%). There were 334 TBI clinic visits, and however, there was no statistically significant correlation between number of hotline calls and number of clinic visits (r = .417; P = .177). CONCLUSIONS: There was widespread utilization of our hotline. Other institutions wishing to adopt similar practices can expect that the majority of calls will be for appointment scheduling or clinical advice. Further work is needed to determine whether implementation of a Neurotrauma Hotline improves resource utilization and patient outcomes.

Paracrine Effects of Leydig Cell Nodular Hyperplasia, Two Case Reports: A Neglected Phenomenon.

Leydig cell nodular hyperplasia (LCNH) is a lesion that is less characterized than the familiar Leydig cell tumors. The paracrine effects of these lesions on adjacent gonadal stroma have not been widely documented. We present two cases of precocious puberty in pre-pubertal boys found to have a single LCNH with adjacent focal maturation of the seminiferous tubules. Blood tests showed elevated serum testosterone and dehydroepiandrosterone (DHEAS). Ultrasound revealed unilateral testicular enlargement with irregular echogenicity. Radical orchiectomy was performed. Histologically Leydig cell nodular proliferation without destruction of surrounding tubules was seen. Mature seminiferous tubules undergoing spermatogenesis were noted adjacent to the lesion, while away from the lesion seminiferous tubules were as expected in pre-pubescent boys. These cases emphasize the potential presence of both paracrine and endocrine effects in Leydig cell nodular hyperplasia. However, instances of the endocrine effects of hyperplastic Leydig cell lesions are more widely reported than the paracrine effects.

Hospital charges associated with motorcycle crash factors: a quantile regression analysis.

BACKGROUND: Previous studies of motorcycle crash (MC) related hospital charges use trauma registries and hospital records, and do not adjust for the number of motorcyclists not requiring medical attention. This may lead to conservative estimates of helmet use effectiveness. METHODS: MC records were probabilistically linked with emergency department and hospital records to obtain total hospital charges. Missing data were imputed. Multivariable quantile regression estimated reductions in hospital charges associated with helmet use and other crash factors. RESULTS: Motorcycle helmets were associated with reduced median hospital charges of $256 (42% reduction) and reduced 98th percentile of $32,390 (33% reduction). After adjusting for other factors, helmets were associated with reductions in charges in all upper percentiles studied. Quantile regression models described homogenous and heterogeneous associations between other crash factors and charges. CONCLUSIONS: Quantile regression comprehensively describes associations between crash factors and hospital charges. Helmet use among motorcyclists is associated with decreased hospital charges.

[Symptoms of social phobia and their relationship to interpersonal characteristics in a sample of German medical students]. / Häufigkeit sozialphobischer Symptome und ihr Bezug zu interpersonalen Merkmalen in einer Stichprobe von Medizinstudierenden.

The study aimed to detect the frequency of social phobia symptoms in a sample of German medical students and to compare students with and without these symptoms related to interpersonal characteristics. 525 students filled out a battery of self-report questionnaires consisting of the LSAS (Liebowitz Social Anxiety Scale), the SPAI (Social Phobia Anxiety Inventory), the IIP-32 (Inventar of interpersonal problems) and the IIM (Inventar of interpersonal motives). Relevant social phobia symptoms were found in 12.2%. Students with symptoms of social phobia differed significantly in subscales of the IIP and the IIM. Students with symptoms of social phobia also had higher scores for interpersonal problems especially related to the main issue of being too "socially avoidant".

Longitudinal experiences of children remaining at home after a first-time investigation for suspected maltreatment.

OBJECTIVE: To describe longitudinal change in risk for children remaining at home following a first-time investigation for suspected maltreatment. STUDY DESIGN: A retrospective cohort study of children remaining at home following first-time investigation for maltreatment using a nationally representative sample of households involved with Child Protective Services. Outcomes include poverty, social support, caregiver depression, intimate partner violence (IPV), drug/alcohol dependence, corporal punishment, and child behavior problems at baseline, 18, and 36 months following first-time Child Protective Services investigation. We present longitudinal models to (1) estimate prevalence of risk factors at each timepoint; and (2) examine associations between risk-specific service referrals and longitudinal change in risk factor prevalence. RESULTS: Our sample represented 1057056 US children remaining at home following first-time investigation for maltreatment. Almost 100000 (9.2%) children experienced out-of-home placement within 36 months. The prevalence of poverty (44.3%), poor social support (36.3%), caregiver depression (24.4%), IPV (22.1%), and internalizing (30.0%) and externalizing (35.8%) child behavior problems was above general population prevalence at baseline and remained high over the next 36 months. Referral to risk-specific services occurred in a minority of cases, but was associated with significant longitudinal reductions in IPV, drug/alcohol dependence, and externalizing child behavior problems. CONCLUSIONS: Children remaining at home following a first-time investigation for maltreatment live with persistent risk factors for repeat maltreatment. Appropriate service referrals are uncommon, but may be associated with meaningful reduction in risk over time. Pediatricians and policy makers may be able to improve outcomes in these families with appropriate service provision and referrals.

Motivational determinants of interpersonal distress: how interpersonal goals are related to interpersonal problems.

This study aimed to link interpersonal goals with interpersonal problems and psychological distress and to investigate changes in these variables during an inpatient psychotherapeutic treatment. Two hundred and fifty-eight patients treated in a psychosomatic hospital completed the German versions of the circumplex scales of interpersonal values, the inventory of interpersonal problems, and the outcome questionnaire before and at the end of their treatment. Patients initially reported a strong need for bonding in the CSIV. Especially interpersonal goals related to avoidant, submissive, and altruistic behavior were associated with a wide range of different interpersonal problems, and were associated with more psychological distress. At the end of treatment, patients showed no substantial changes in their predominant communal goals, but significantly reduced submissive goals. Additionally, changes of these goals were associated with changes of various interpersonal problems and psychological distress. Focusing the value patients place on submissive experiences could help to improve interpersonal problems.

Phenotypic characteristics and variability in CHARGE syndrome: a PRISMA compliant systematic review and meta-analysis.

BACKGROUND: CHARGE syndrome (OMIM #214800) is a phenotypically complex genetic condition characterised by multi-system, multi-sensory impairments. Behavioural, psychological, cognitive and sleep difficulties are not well delineated and are likely associated with biopsychosocial factors. METHODS: This meta-analysis investigated the prevalence of clinical features, physical characteristics and conditions, behavioural, psychological, cognitive and sleep characteristics in CHARGE syndrome, and statistically evaluated directional associations between these characteristics. Pooled prevalence estimates were calculated using reliable, prespecified quality weighting criteria, and meta-regression was conducted to identify associations between characteristics. RESULTS: Of the 42 eligible studies, data could be extracted for 1675 participants. Prevalence estimates were highest for developmental delay (84%), intellectual disability (64%), aggressive behaviour (48%), self-injurious behaviour (44%) and sleep difficulties (45%). Meta-regression indicated significant associations between intellectual disability and choanal atresia, intellectual disability and inner ear anomalies, sleep difficulties and growth deficiency, and sleep difficulties and gross motor difficulties. CONCLUSIONS: Our comprehensive review of clinical features, behavioural, psychological, cognitive and physical characteristics, conditions and comorbidities in CHARGE syndrome provides an empirically based foundation to further research and practice.

Exercise training and cognition in multiple sclerosis: The GET Smart trial protocol.

BACKGROUND AND OBJECTIVES: Multiple sclerosis (MS) causes cognitive impairment in approximately 50% of cases. Disease modifying medications and cognitive rehabilitation produce only small positive effects on cognition in MS. Converging animal and human research suggests that aerobic exercise may improve cognition in people with MS, but definitive trials are lacking. We describe the design of the GET Smart study, a randomized controlled trial comparing the effects of aerobic exercise versus stretching and toning on cognition in MS. METHODS: The study is a single-blind, parallel group randomized (1:1) controlled trial that compares aerobic exercise training with an active control group consisting of stretching and toning exercises for improving cognition. Participants are nondepressed, ambulatory, non-exercising adults with MS aged 18-54 years who have below average cognitive processing speed. Both treatments were designed to generate equivalent outcome expectancies and entailed supervised, progressive exercise programs, 3 times per week for up to 40 min over a 6 month period. PROJECTED PATIENT OUTCOMES: The primary hypothesis is that the aerobic training group will demonstrate significantly greater cognitive processing speed compared with the control group at the end of the treatment phase (6 months) as measured by a composite of the Paced Auditory Serial Additon Test and the oral Symbol-Digit Modalities Test using intent-to treat analyses. Secondary outcomes are neuropsychological functioning and cardiorespiratory fitness as well as participant reported outcomes such as depression, sleep, and fatigue. Study findings will inform future research, patient education, clinical care and policymaking. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT02106052.

Quantification of penicillin G during labor and delivery by capillary electrophoresis.

In this study, a capillary electrophoresis (CE) method was developed as a means to measure levels of penicillin G (PCN G) in Group B Streptococcus (GBS) positive pregnant women during labor and delivery. Volunteers for this developmental study were administered five million units of PCN G at the onset of labor. Urine, blood, and amniotic fluid samples were collected during labor and post delivery. Samples were semi-purified by solid-phase extraction (SPE) using Waters tC18 SepPak 3cc cartridges with a sodium phosphate/methanol step gradient for elution. Capillary electrophoresis or reversed-phase high-performance liquid chromatography (RP-HPLC) with diode-array absorbance detection were used to separate the samples in less than 30 min. Quantification was accomplished by establishing a calibration curve with a linear dynamic range. The tC18 SPE methodology provided substantial sample clean-up with high recovery yields of PCN G ( approximately 90%). It was found that SPE was critical for maintaining the integrity of the separation column when using RP-HPLC, but was not necessary for sample analysis by CE where no stationary phase is present. Quantification results ranged from millimolar concentrations of PCN G in maternal urine to micromolar concentrations in amniotic fluid. Serum and cord blood levels of PCN G were below quantification limits, which is likely due to the prolonged delay in sample collection after antibiotic administration. These results show that CE can serve as a simple and effective means to characterize the pharmacokinetic distribution of PCN G from mother to unborn fetus during labor and delivery. It is anticipated that similar methodologies have the potential to provide a quick, simple, and cost-effective means of monitoring the clinical efficacy of PCN G and other drugs during pregnancy.

Interpersonal problem behavior and low back pain.

OBJECTIVE: The theory of interpersonal problem behaviour (IPB) provides a more fundamental framework for understanding the psychosocial aspects of pain. The present study focused on the IPB, based on the Interpersonal Problem Circumplex (IPC), in persons with low back pain and its association with pain, psychological characteristics, and health care utilisation. METHODS: In a cross-sectional design, individuals with back pain (N = 88) and healthy control persons who matched by age, gender, and educational level (N = 88) were compared with regard to IPB. Furthermore, back pain patients classified by their IPB (N = 24 low, N = 48 moderate, N = 16 high) were compared regarding pain, depression, catastrophising, and health care utilisation. RESULTS: In comparison to the healthy reference sample, a significant difference in the interpersonal problems of the low back pain group, with a tendency towards being overly 'introverted', 'exploitable', and 'subassertive', was revealed. In the back pain group, participants with elevated IPB showed significantly higher levels of pain intensity, functional disability, depression, catastrophising, and health care utilisation than participants with IPB in the normal range. CONCLUSION: Application of the Interpersonal Circumplex Model can help to characterize a subgroup of persons with low back pain. Increased general interpersonal problems are associated with elevated burden in pain-related, psychological, and health care-related variables. Future research should focus on the treatment opportunities for this subgroup, as well as on the influence of interpersonal problems during the course of back pain.

Training: improving antenatal detection and outcomes of congenital heart disease.

OBJECTIVES: This study describes the design, delivery and efficacy of a regional fetal cardiac ultrasound training programme. This programme aimed to improve the antenatal detection of congenital heart disease (CHD) and its effect on fetal and postnatal outcomes. DESIGN SETTING AND PARTICIPANTS: This was a prospective study that compared antenatal CHD detection rates by professionals from 13 hospitals in Wales before and after engaging in our 'skills development programme'. Existing fetal cardiac practice and perinatal outcomes were continuously audited and progressive targets were set. The work was undertaken by the Welsh Fetal Cardiovascular Network, Antenatal Screening Wales (ASW), a superintendent sonographer and a fetal cardiologist. INTERVENTIONS: A core professional network was established, engaging all stakeholders (including patients, health boards, specialist commissioners, ASW, ultrasonographers, radiologists, obstetricians, midwives and paediatricians). A cardiac educational lead (midwife, superintendent sonographer, radiologist, obstetrician, or a fetal medicine specialist) was established in each hospital. A new cardiac anomaly screening protocol ('outflow tract view') was created and training on the new protocol was systematically delivered at each centre. Data were prospectively collected and outcomes were continuously audited: locally by the lead fetal cardiologist; regionally by the Congenital Anomaly Register and Information Service in Wales; and nationally by the National Institute for Cardiac Outcomes and Research (NICOR) in the UK. MAIN OUTCOME MEASURES: Patient satisfaction; improvements in individual sonographer skills, confidence and competency; true positive referral rate; local hospital detection rate; national detection rate of CHD; clinical outcomes of selected cardiac abnormalities; reduction of geographical health inequality; cost efficacy. RESULTS: High levels of patient satisfaction were demonstrated and the professional skill mix in each centre was improved. The confidence and competency of sonographers was enhanced. Each centre demonstrated a reduction in the false-positive referral rate and a significant increase in cardiac anomaly detection rate. According to the latest NICOR data, since implementing the new training programme Wales has sustained its status as UK lead for CHD detection. Health outcomes of children with CHD have improved, especially in cases of transposition of the great arteries (for which no perinatal mortality has been reported since 2008). Standardised care led to reduction of geographical health inequalities with substantial cost saving to the National Health Service due to reduced false-positive referral rates. Our successful model has been adopted by other fetal anomaly screening programmes in the UK. CONCLUSIONS: Antenatal cardiac ultrasound mass training programmes can be delivered effectively with minimal impact on finite healthcare resources. Sustainably high CHD detection rates can only be achieved by empowering the regional screening workforce through continuous investment in lifelong learning activities. These should be underpinned by high quality service standards, effective care pathways, and robust clinical governance and audit practices.

Motorcycle helmet effectiveness in reducing head, face and brain injuries by state and helmet law.

BACKGROUND: Despite evidence that motorcycle helmets reduce morbidity and mortality, helmet laws and rates of helmet use vary by state in the U.S. METHODS: We pooled data from eleven states: five with universal laws requiring all motorcyclists to wear a helmet, and six with partial laws requiring only a subset of motorcyclists to wear a helmet. Data were combined in the Crash Outcome Data Evaluation System's General Use Model and included motorcycle crash records probabilistically linked to emergency department and inpatient discharges for years 2005-2008. Medical outcomes were compared between partial and universal helmet law settings. We estimated adjusted relative risks (RR) and 95 % confidence intervals (CIs) for head, facial, traumatic brain, and moderate to severe head/facial injuries associated with helmet use within each helmet law setting using generalized log-binomial regression. RESULTS: Reported helmet use was higher in universal law states (88 % vs. 42 %). Median charges, adjusted for inflation and differences in state-incomes, were higher in partial law states (emergency department $1987 vs. $1443; inpatient $31,506 vs. $25,949). Injuries to the head and face, including traumatic brain injuries, were more common in partial law states. Effectiveness estimates of helmet use were higher in partial law states (adjusted-RR (CI) of head injury: 2.1 (1.9-2.2) partial law single vehicle; 1.4 (1.2, 1.6) universal law single vehicle; 1.8 (1.6-2.0) partial law multi-vehicle; 1.2 (1.1-1.4) universal law multi-vehicle). CONCLUSIONS: Medical charges and rates of head, facial, and brain injuries among motorcyclists were lower in universal law states. Helmets were effective in reducing injury in both helmet law settings; lower effectiveness estimates were observed in universal law states.

Motor Vehicle Crashes, Medical Outcomes, and Hospital Charges Among Children Aged 1-12 Years - Crash Outcome Data Evaluation System, 11 States, 2005-2008.

PROBLEM: Motor vehicle crashes are a leading cause of death among children. Age- and size-appropriate restraint use is an effective way to prevent motor vehicle-related injuries and deaths. However, children are not always properly restrained while riding in a motor vehicle, and some are not restrained at all, which increases their risk for injury and death in a crash. REPORTING PERIOD: 2005-2008. DESCRIPTION OF THE SYSTEM: The Crash Outcome Data Evaluation System (CODES) is a multistate program facilitated by the National Highway Traffic Safety Administration to probabilistically link police crash reports and hospital databases for traffic safety analyses. Eleven participating states (Connecticut, Georgia, Kentucky, Maryland, Minnesota, Missouri, Nebraska, New York, Ohio, South Carolina, and Utah) submitted data to CODES during the reporting period. Descriptive analysis was used to describe drivers and child passengers involved in motor vehicle crashes and to summarize crash and medical outcomes. Odds ratios and 95% confidence intervals were used to compare a child passenger's likelihood of sustaining specific types of injuries by restraint status (optimal, suboptimal, or unrestrained) and seating location (front or back seat). Because of data constraints, optimal restraint use was defined as a car seat or booster seat use for children aged 1-7 years and seat belt use for children aged 8-12 years. Suboptimal restraint use was defined as seat belt use for children aged 1-7 years. Unrestrained was defined as no use of car seat, booster seat, or seat belt for children aged 1-12 years. RESULTS: Optimal restraint use in the back seat declined with child's age (1 year: 95.9%, 5 years: 95.4%, 7 years: 94.7%, 8 years: 77.4%, 10 years: 67.5%, 12 years: 54.7%). Child restraint use was associated with driver restraint use; 41.3% of children riding with unrestrained drivers also were unrestrained compared with 2.2% of children riding with restrained drivers. Child restraint use also was associated with impaired driving due to alcohol or drug use; 16.4% children riding with drivers suspected of alcohol or drug use were unrestrained compared with 2.9% of children riding with drivers not suspected of such use. Optimally restrained and suboptimally restrained children were less likely to sustain a traumatic brain injury than unrestrained children. The 90th percentile hospital charges for children aged 4-7 years who were in motor vehicle crashes were $1,630.00 and $1,958.00 for those optimally restrained in a back seat and front seat, respectively; $2,035.91 and $3,696.00 for those suboptimally restrained in a back seat and front seat, respectively; and $9,956.60 and $11,143.85 for those unrestrained in a back seat and front seat, respectively. INTERPRETATION: Proper car seat, booster seat, and seat belt use among children in the back seat prevents injuries and deaths, as well as averts hospital charges. However, the number, severity, and cost of injuries among children in crashes who were not optimally restrained or who were seated in a front seat indicates the need for improvements in proper use of age- and size-appropriate car seats, booster seats, and seat belts in the back seat. PUBLIC HEALTH ACTIONS: Effective interventions for increasing proper child restraint use could be universally implemented by states and communities to prevent motor vehicle-related injuries among children and their resulting costs.

Resolution of intimate partner violence and child behavior problems after investigation for suspected child maltreatment.

OBJECTIVE To describe longitudinal change in child behavior problems associated with resolution of intimate partner violence (IPV) after an investigation for suspected child maltreatment. DESIGN Retrospective cohort study. SETTING The National Survey of Child and Adolescent Well-Being, a nationally representative longitudinal sample of US households investigated for suspected child maltreatment. PARTICIPANTS The study included 320 school-aged subjects with caregiver-reported IPV in the year prior to baseline interview. Caregivers were interviewed an average of 3, 20, 36, and 81 months following investigation. MAIN EXPOSURE Resolution vs persistence of baseline IPV. Persistence was defined by report of IPV during any follow-up interview. MAIN OUTCOME MEASURES Clinically significant internalizing or externalizing child behavior problems. RESULTS In total, 44.6% of caregivers who reported IPV at the baseline interview reported persistent IPV. After adjusting for significant covariates, IPV resolution was associated with an 11.9% reduction in internalizing problems by 81 months (P = .03); IPV persistence was associated with persistence in baseline problems. Resolution of IPV was associated with an 18.5% reduction in externalizing problems by 20 months that was sustained at 36 and 81 months (all P < .05). Intimate partner violence persistence was associated with a steady but nonsignificant increase in externalizing behavior problems during 81 months (10.1%, P = .07). The adjusted relative risks for internalizing and externalizing behavior problems 81 months following a child protective services investigation for children exposed to persistent vs resolved IPV were 1.79 (95% CI, 0.91-3.52) and 1.88 (95% CI, 1.12-3.18), respectively. CONCLUSIONS Resolution of IPV after a child protective services investigation for suspected child maltreatment is associated with meaningful, sustained reductions in clinically significant child behavior problems.

Measurement of patient involvement - what do concepts of psychotherapy research contribute?

The article comments on Shared Decision Making (SDM) research from a different perspective, i.e. psychotherapy research. Psychotherapy research had to face similar challenges, both conceptual as well as methodological. Meanwhile, the generic model of psychotherapy has helped researchers to put single results into a perspective that also might be helpful to the SDM field. Since SDM research increasingly focuses upon process perspectives directed towards the doctor-patient dyad, we propose measures and constructs from interpersonal theory as useful tools to be introduced into SDM research. A selection of these measures and their potential within SDM research is described.

Are fatigue symptoms and chronic fatigue syndrome following Q fever infection related to psychosocial variables?

OBJECTIVE: Fatigue is known as one of the most common long-term sequelae of Q fever infections. The study aimed to determine the prevalence of fatigue symptoms, chronic fatigue, and chronic fatigue syndrome (CFS) in a sample of patients who were exposed to Q fever (Coxiella burnetii) infection compared to controls, and to contrast Q fever patients with and without fatigue symptoms related to somatoform symptoms, hypochondriacal worries and beliefs, psychosocial complaints, and social support. METHODS: Cross-sectional study of 84 Q fever exposed patients from a specific region in Jena (Germany) and 85 matched controls using standardized questionnaires (MFI, SF-12, CDC-SI, SOMS, Whiteley Index, OQ-45 and F-Sozu). Diagnostic interviews were performed to validate questionnaire results in a smaller subsample. RESULTS: Patients who were exposed to a Q fever infection in the past indicated more fatigue symptoms and chronic fatigue than controls (54.8 vs. 20%, 32.1 vs. 4.7%) but did not show more criteria for a CFS (1 patient in each group). Q fever patients showing fatigue symptoms revealed significantly higher scores in the SOMS, the Whiteley-Index, and higher psychosocial complaints measured with the OQ-45. Their health related Quality of Life was reduced, no differences were found related to perceived social support. CONCLUSION: Although in our sample fatigue symptoms were common among Q fever patients, we found no increased prevalence of CFS in contrast to several other studies. The combination of fatigue symptoms with other psychosocial symptoms/problems support the view of a biopsychosocial etiology of fatigue symptoms.