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Objective This investigation will focus on two areas: 1) early communication impairments as predictors of autism spectrum disorder (ASD) and later developmental delays, and 2) the relationship between communication and evidence of CNS function (sleep, EEG) and structure (MRI DTI and volumetrics) in young children at risk for ASD. The objective is to delineate early communicative impairments that predict ASD vs. other developmental delays and to examine how these impairments correlate with brain abnormalities in both structure and function. Study Population We will recruit 64 children [n=32 at 12 months of age (plus or minus 2 months); n=32 at 18 months of age (plus or minus 2 months)] who are at-risk for ASD due to communication/language delays (at-risk group). The at-risk children will be matched at initial on chronological age, SES, and sex, to typically developing children (n=75) with no history of developmental delays. These 139 participants will hereafter be referred to as the toddler sample. At the 36 month final visit, diagnostic status (e.g. ASD, non-ASD specific delays, catch up) will be determined for children in the at-risk group. In addition, 10 healthy adults, aged 18-40 will serve as control participants for the purpose of piloting the functional paradigms for the MRI portion of the protocol. Design We propose to conduct a prospective, longitudinal study of toddlers at-risk for ASD compared to typically developing toddlers. Children will complete behavioral testing and an overnight Sleep/EEG as well as MRI at either a 12 or 18 month initial. Follow-up visits that include behavioral assessment will occur at 24 and 36 months for all children (and at 18 months of age for the 12-month cohort). The Sleep/EEG and MRI will be repeated at the 36 month final follow-up. Outcome Measures Autism symptoms, language status, and cognitive development at 36 months will serve as the primary outcome measures. The purpose of this study is to learn more about risk factors for autism by studying the behavior and brain functioning of toddlers with early communication delays and typically developing toddlers. Children 12 or 18 months of age with language delays (i.e., no words at 18 months, limited vocalizations at 12 months) and typically developing toddlers may be eligible to participate. This study will be conducted at the NIH Clinical Center in Bethesda, Maryland. There will be an initial screening evaluation that will include behavioral assessment. Eligible participants will then complete a baseline visit that includes an overnight sleep study that includes Electroencephalogram (EEG) test to measure brain electrical activity, and an MRI scan. Follow-up visits that include behavioral assessment will occur every 6-12 months, depending on age at study entry. The final study visit will occur at 36 months of age and will include behavioral assessment, sleep/EEG study, and MRI. There is no cost for participation. Compensation will be provided. To find out if your child qualifies or for more information, please call 301-451-7822 (TTY: 1-866-411-1010) or e-mail NIMH-ASD@mail.nih.gov. National Institute of Mental Health, National Institutes of Health, Department of Health & Human Services....

To compare the efficacy and safety of a select serotonin re-uptake inhibitor (SSRI, sertraline) and a tricyclic antidepressant (TCA, nortriptyline) in outpatients over the age of 60 who meet Diagnostic and Statistical Manuel-IV criteria for unipolar major depression, excluding patients who meet criteria for psychotic or atypical subtype. To test the hypothesis that medication condition interacts with diagnostic subtype (melancholic vs non-melancholic) in determining antidepressant response. To examine the roles of symptom severity and alternative diagnostic subtyping in contributing to this pattern. SSRIs are effective in the treatment of major depression. However, there is also evidence that SSRIs may be significantly less effective than TCAs for depressed patients with melancholia. This issue is of particular concern in late-life major depression. SSRIs have important safety advantages with respect to overdose and a benign cardiovascular profile. Furthermore, the SSRIs do not have significant anticholinergic effects, and appear to be better tolerated than the TCAs. Perhaps most important, the SSRIs currently are prescribed widely as the medication treatment of first choice for major depression in late life. Therefore, if it were determined that SSRIs are considerably less effective than TCAs in the treatment of melancholia in the elderly, there would be significant ramifications for clinical practice. Randomization to sertraline (a SSRI) or nortriptyline (a TCA) is stratified by the presence or absence of melancholia. Outcome measures for the 12-week acute phase include clinician and patient ratings of symptoms, side effects, and an evaluation of the health-related quality of life (HRQOL). At the end of the acute treatment phase, patients who meet criteria for clinical response participate in a 6-month continuation phase. The purpose of this study is to compare the safety and effectiveness of a select serotonin re-uptake inhibitor (SSRI, sertraline) and a tricyclic antidepressant (TCA, nortriptyline) in outpatients over the age of 60 who have major depression. SSRIs are effective in the treatment of major depression. However, there is also evidence that SSRIs may be significantly less effective than TCAs for patients with late-life major depression with melancholia. Since SSRIs seem to be easier to take than TCAs and are more widely prescribed, it is important to determine which of these types of antidepressants works best to treat these patients. Patients will be assigned randomly to receive either sertraline (a SSRI) or nortriptyline (a TCA) for 12 weeks. Patients will be monitored for symptoms, side effects, and quality of life. If a patient responds to treatment, he/she will participate in a 6-month continuation phase in which he/she will continue to receive the same medication. An individual may be eligible for this study if he/she: Has unipolar major depression (with some exceptions) and is over 60 years old.

The purpose of the study proposed is to investigate the role of neurosteroids and GABA in the pathophysiology and treatment of premenstrual dysphoric disorder (PMDD) by 1) measuring cortical gama-aminobutyric acid levels (GABA levels) using nuclear magnetic resonance spectroscopy (MRS) during the follicular and mid-luteal phases of the menstrual cycle pre and post treatment with the selective serotonin reuptake inhibitor (SSRI) fluoxetine (Prozac®, Sarafem®), and 2) correlating cerebrospinal fluid (CSF) and plasma GABA and neurosteroid levels with cortical GABA levels at these same time points. Neurosteroids to be measured include allopregnanolone, pregnenolone, and pregnenolone sulfate. Findings from women with PMDD will be compared to those of healthy subjects.

The human prion diseases have been traditionally classified into Creutzfeldt-Jakob disease (CJD), Gerstmann-Sträussler-Scheinker (GSS) disease and kuru. They can alternatively be classified into three causal categories: sporadic, acquired and inherited. The appearance of a new human prion disease, variant CJD (vCJD), in the United Kingdom from 1995 onwards, and the experimental evidence that this is caused by the same prion strain as that causing bovine spongiform encephalopathy (BSE) in cattle, has raised the possibility that a major epidemic of vCJD will occur in the United Kingdom and other countries as a result of dietary or other exposure to BSE prions. These concerns have led to intensified efforts to develop therapeutic interventions. Quinacrine has been previously used to treat other diseases such as malaria; however, it was found to have serious side effects and is no longer licensed in the United Kingdom. There is only very limited evidence from laboratory tests for the potential use of quinacrine in human prion disease, and the evidence to date for any possible clinical benefit is very scarce. The PRION-1 trial is being undertaken since there are no other drugs currently available which are considered suitable for human evaluation. PRION-1 aims to assess the activity and safety of Quinacrine (Mepacrine hydrochloride) in human prion disease. It also aims to establish an appropriate framework for the clinical assessment of therapeutic options for human prion disease that can be refined or expanded in the future, as new agents become available.

This was an open label assessment of hydroxyurea pharmacokinetics and relative bioavailability conducted in two independent cohorts of pediatric patients with sickle cell anemia or sickle beta-zero thalassemia. A total of 42 participant were enrolled, out of which 39 were enrolled and dosed. A one-compartment population PK model was successfully developed to describe the time course of hydroxyurea concentrations after oral administration in sickle cell anemia participants from both study arms. The relative bioavailability analysis showed very similar pharmacokinetics for peroral liquid and capsule formulations. No adverse events (AEs) were classified as being caused by the study drug, and no AEs led to study drug interruption. Lastly, no significant changes from baseline in laboratory values, vital signs, or physical examination results were found. Hydroxyurea was well tolerated as evidenced by safety monitoring and reporting.

This is a multicentre prospective randomised controlled trial to determine whether a reduction of body temperature by 3-4°C following perinatal asphyxia improves survival without neurodevelopmental disability. Full term infants will be randomised within 6 hours of birth to either a control group with the rectal temperature kept at 37 ± 0.2°C or to whole body cooling with the rectal temperature kept at 33.5 ± 0.5°C for 72 hours followed by slow rewarming. The outcome will be assessed at 18 months of age by survival and neurological and neurodevelopmental testing. Eligibility criteria: Term infants less than 6 hours after birth with moderate or severe perinatal asphyxia (a combination of clinical and EEG criteria). Exclusion criteria: Infants expected to be 6 hours of age at the time of randomisation or infants with major congenital abnormalities. Intervention: Intensive care with whole body cooling versus intensive care without whole body cooling (babies are cooled to 33.5°C for 72 hours) Main Outcomes: Death and severe neurodevelopmental impairment at 18 months of age Secondary Outcomes: Cerebral thrombosis or haemorrhage, persistent hypotension, pulmonary hypertension, abnormal coagulation, arrhythmia and sepsis in the neonatal period. Neurological impairments at 18 months Number of patients required: 236. On 30th November 2006, when recruitment closed, 325 babies had been recruited. Hypothesis: Prolonged whole body cooling in term infants with perinatal asphyxial encephalopathy reduces death and severe neurodevelopmental disability. This study aims to determine whether whole body cooling to 33-34°C is a safe treatment that improves survival, without severe neurological or neurodevelopmental impairments at 18 months, of term infants suffering perinatal asphyxial encephalopathy.

Fish oils have many proven benefits for a wide range of clinical arenas such as ischaemic heart disease, rheumatoid arthritis and inflammatory bowel disease. Recent research has described the beneficial effects of intravenous fish oils for surgical patients, such as reduced hospital stay, reduced re-operation rate and reduced requirements for intravenous antibiotics. These are in part due to the anti-inflammatory effects of fish oils. There is evidence that fish oils are also effective against cancer, large population studies indicate that diets rich in omega-3 are associated with a lower incidence of cancer, and in vitro and animal studies demonstrate anti-tumour effects of fish oils 1. Fish oils inhibit the growth of different human cancer cell lines 2. They act specifically on tumour cells only and do not impair the function of normal cells 3. EPA and DHA inhibit the growth of human cancer cell lines and enhance apoptosis. 4. Fish oil induces apoptosis in human colorectal cancer cell lines in-vitro after 48hrs incubation 5. Fish oil has been shown to inhibit the proliferation activities, inhibit the invasive activities and increase the apoptosis of human pancreatic carcinoma cell lines in-vitro after only 48hrs of exposure 6. Fish oil has been shown to enhance colorectal adenocarcinoma cell lines sensitivity to radiotherapy 7. Fish oil has also been shown to reduce the incidence of liver metastases in experimentally induced ductal pancreatic cancer in rats after 30 weeks of oral treatment with an omega-3 supplemented diet. 8. Lung cancer xenografts in animals fed with fish oil showed significantly increased tumour regression in response to doxorubicin compared to those fed with omega-3. This study aims to assess the effect of omega-3 FA upon hepatic colorectal metastases in a pilot study. 20 patients will be selected for this pilot study with potentially resectable hepatic colorectal adenocarcinoma metastases. 10 patients will receive total parenteral nutrition (TPN) without fish oils (controls), 10 will receive fish oil containing lipid emulsion in their TPN. Changes in tumour angiogenesis (increased angiogenesis is associated with a poorer prognosis in hepatic colorectal metastases) will be investigated using digital contrast enhanced MRI scanning, and markers of angiogenesis will be investigated in blood and resected tumour samples from the patients. It is a randomised controlled double blind trial. The purpose of this study is to determine whether fish oils - a known source of omega-3 given intravenously (via a 'drip') will help cure secondary deposits in the liver from bowel cancer.

In 'real-world' health care settings there exist a number of circumstances where the weight of a child is desirable or even necessary but unavailable. The most conspicuous of these settings can be found in developing countries where many medical clinics lack suitable scales to obtain accurate infant and child weights. Though resource restrictions are less of an issue in developed countries, scenarios still exist where weight assessment is problematic. For example, accurate estimates of a child's weight are rarely available during emergency or trauma situations, and in some in-patient settings (e.g. critical care units, orthopedic clinics) obtaining an accurate patient weight can be impaired by the presence of external hoses, tubing, casts, and/or other medical equipment. Irrespective of the environment, the challenge that each of these settings present is the same; namely, the provision of age-appropriate, weight-based interventions which remain the most accurate approach to delivering therapy in children. Thus, techniques which permit accurate weight estimation address a critical medical need in both developing and developed countries. Numerous weight estimation strategies have been described with each used to varying degrees in clinical practice. Many of the published techniques have distinct advantages. For example; simple age-based equations can be used without the need for reference materials, strategies that utilize preprinted tables or tools limit the risk of calculation errors. Other techniques present unnecessary complexities for the end-user including; the need for subjective assessments of habitus, the requirement to solve exponential equations, the call for multiple formulae delineated by age bracket, or the reliance on one or more reference charts. Irrespective of their simplicity or complexity, almost all of the reported techniques have significant limitations. Relatively few methods have been evaluated in pediatric populations of varying races, ethnicities and nationalities and essentially no single previously described method provides accurate estimates of weight across broad age- and weight-bands. Apart from parental recall which can vary in accuracy, the most commonly used strategies for estimating weight rely on the child's age, length, or a combination of the two parameters. While simple and easy to integrate into a weight estimation technique, age based strategies fail to account for the extremes of body composition and stature that are observed in children of the same age. Similarly, length based strategies do not take into consideration that two children of the same height may demonstrate markedly discrepant weights based on underlying nutritional status (e.g. malnourished, underweight, overweight, obese). Consequently, many of the currently available weight estimation strategies perform well in only a small subset of children. As such, there remains a critical need for weight estimation methods that are accurate across a wide range of pediatric ages, weights, lengths, nationalities and body compositions despite the relative abundance of strategies that already exist. Investigators at Children's Mercy Hospitals and Clinics recently developed and validated a weight estimation method (the Mercy MethodTM) that addresses the principal limitations of previously published methods, requires no subjective assessment and performs robustly independently of age and length over a broad range of weights. As with other strategies, the Mercy Method incorporates growth velocity but uses humeral length as a surrogate for total body length. Total body length will be discrepant depending on whether the measurement is obtained with the child standing or lying down and can be difficult to obtain in a child who is uncooperative or obtunded. The Mercy Method also incorporates body habitus as a quantitative variable which improves the accuracy of the overall length-based weight estimate and removes the subjective nature of categorizing the child's body type into one of a few alternatives (e.g. "slim," "average," or "heavy"). By developing a model with these considerations in mind we were able to expand the age range to which our weight estimation method can be applied and remove length restrictions which are typically imposed because of the disproportionate increase in weight-for-height observed as children get older. In brief, demographic and anthropometric data on children 2 months to 16 years of age were extracted from the NHANES database and individual datasets were randomly assigned into a method development (n=17,328) or a method validation (n=1,938) set. Humeral length (HL) and mid-upper arm circumference (MUAC) were used to develop a weight estimation method by 1) collapsing length and habitus measurements into discrete bins, 2) examining the median population weight for each bin-pair, 3) statistically weighting the bin-pairs for age and sample size, and 4) calculating a fractional weight for each HL and MUAC. An individual weight estimate is generated by the simple addition of the MUAC and HL fractional bin value that corresponds to that individual child's measurements. The predictive performance this method was evaluated using the internal validation set and compared with the performance of 13 previously published weight estimation methods applied to the same data. The Mercy Method outperformed the 13 other published methods when evaluated for goodness-of-fit, mean error, mean percentage error, root mean square error and percentage of children in agreement within 10% of actual weight. Most of the age-and length-based strategies examined overestimated weight in children classified, by BMI, as underweight and significantly underestimated weight in children classified as overweight or obese. The degree to which this occurred depended largely on the constants driving their mathematical equations, with some methods biased toward more accurate prediction in children of lower weight (e.g. Broselow) and others performing better among children in the higher weight brackets (e.g. Theron). Irrespective of directionality, the bias observed with some methods at the extremes of weight represented as much as a 3-fold error between predicted and actual weights. Discrepancies of this magnitude can be dangerous, and potentially life-threatening, depending on how 'forgiving' the intervention or treatment that is being administered. The singular habitus-based method (i.e. Cattermole) ranked among the best (after the Mercy Method) with respect to absolute bias; however, it performed only moderately well when precision and MPE were factored into the assessment. This method, which was developed in Chinese children consistently overestimated weight at lower absolute weights and underestimated weight at higher absolute weight irrespective of BMI percentile. This suggests that while the relationship between weight and MUAC tends to be linear within any given population, the mathematical constants that define the relationship differ between populations having different height-for-weight averages. Given the nature of the data used to develop and validate the Mercy Method, comparative performance of the Devised Weight Estimation Method (DWEM, the only other method to incorporate both body length and body habitus) could not be assessed. Notably, the DWEM involves a subjective rating of "slim," "average," or "heavy". While DWEM has been shown to outperform other age-based methods, the categorical assignment of habitus coupled with inconsistencies in subjective assessment between and within observers [inter-rater agreement- 78% (range: 58-93%); intra-rater agreement- 86% (range: 81-94%)] contributed to bias and precision estimates that were larger than observed with strategies based solely on length. While the Mercy Method can be used as a reference table, a more practical application was the development of a simple and inexpensive device that can perform the two required measurements simultaneously and report the predicted weight directly from the device as opposed to consulting a separate table or chart. Consequently, the 3D Mercy TAPE was developed to perform both measurements simultaneously requiring no external references to arrive at the weight estimate for a given child. An alternative 2D Mercy TAPE was also designed . It requires two serial measurements with the same simple addition used with the 3D TAPE but does not require any folding or manipulation when removed from its packaging. Both devices are intended to be printed on any flexible, non-stretchable medium (e.g. paper, plastic coated paper, fiberglass) so as to be disposable or semi-permanent, inexpensive to mass produce and easy to store. In its numeric form, the Mercy TAPE would be expected have limited utility in settings where care providers are illiterate or do not use a written language. However, the tool can be easily revised with colors and/or symbols whose combination would correspond to a given dose, intervention strategy or weight target. While the Mercy Method is expected to perform well in U.S. children given its creation using data from a U.S. database, external validation of the in non-U.S. settings is currently ongoing with support of the World Health Organization to gauge its utility in children of varying ethnicity and geographic origin. The related 2D and 3D Mercy TAPE still awaits prospective evaluation. The requisite study to satisfy the validation requirements are described herein under the hypothesis: The Mercy TAPE will demonstrate the same predictive performance as the Mercy method in an independent pediatric assessment. In 'real-world' health care settings there exist a number of circumstances where the weight of a child is desirable or even necessary but unavailable. Numerous weight estimation strategies have been described but each has limitations. Investigators at Children's Mercy Hospitals and Clinics recently developed a weight estimation method and tool that addresses the limitations of previously published methods. This study is intended to validate the device in a population of children 2 months to 16 years of age.

Background: Animal evidence indicates that some consolidated memories when reactivated (retrieved) need to be reconsolidated. During this process, memories can be enhanced or weakened. In a preliminary, randomized, double-blind, placebo-controlled study, we tested whether post-reactivation administration of the beta-adrenergic blocker propranolol, which reduces reconsolidation of aversive memories in rodents, would reduce the emotional strength of traumatic memories, or conditioned fear responses, in patients with non-combat-related PTSD. Civilian participants described their traumatic event during a "script preparation" session and thereafter received either a combined dose of short- and long-acting propranolol (n=9), or placebo (n=10). A week later, they engaged in script-driven mental imagery of their personal traumatic events, while peripheral physiologic responses were recorded as measures of the emotional strength of the traumatic memory. We found that physiologic responses were significantly smaller in the participants who had received post-reactivation propranolol compared to placebo a week earlier: F(3,15)=5.1, p=.007, η2=.49. The results of this preliminary study are consistent with pharmacologic blockade of reconsolidation of traumatic memories in PTSD. However, several important questions remain unanswered. First, does propranolol also weaken traumatic memories in combat-related PTSD? Second, does this weakening effect only occur when the propranolol is given when combined with traumatic memory reactivation? If not, this would refute the reconsolidation hypothesis and suggest that propranolol affects non-specific mechanisms. Third, how long does the traumatic memory weakening last, i.e., does recovery of the conditioned fear response occur? Objective/Hypothesis: The first objective is to replicate and extend the finding from the preliminary study to Iraq and Afghanistan combat veterans with PTSD by showing that propranolol following combat memory reactivation results in a significantly greater weakening of traumatic combat memories than propranolol alone, supporting the proposition that this weakening is due to pharmacological blockade of memory reconsolidation, rather than non-specific actions of propranolol. We hypothesize that participants who undergo script preparation for the combat event(s) that caused their PTSD, followed by (post-reactivation) propranolol, will show significantly smaller psychophysiologic responses during script-driven imagery testing a week later compared to those who receive (non-reactivation) propranolol two days prior to combat script preparation. The second objective to show that this effect is long-lasting, which would be expected if the underlying mechanism is reduction of the traumatic memory trace by blockade of reconsolidation. We hypothesize that the effect will remain significant when participants undergo follow-up psychophysiologic script-driven imagery testing six months later. Specific Aim: To perform a controlled, randomized, double-blind study in Iraq and Afghanistan veterans with combat-related PTSD that addresses the above hypotheses. Study Design: Participants will be randomly assigned to one of two groups: post-reactivation propranolol or non-reactivation propranolol. After written informed consent is obtained, participants randomized to the non-reactivation propranolol group will receive a "test" dose of 0.67 mg/kg short-acting propranolol combined with 1 mg/kg long-acting propranolol. Participants randomized to the post-reactivation propranolol group will receive matching placebo capsules. Two days later, all participants will return for an approximate 15-30 minute "script preparation" session, at which time they will describe the details of their traumatic combat event(s) to the Principal Investigator. Participants randomized to the post-reactivation propranolol group will then receive the combined propranolol dose, whereas participants randomized to the non-reactivation propranolol group will receive placebo. Based upon the history obtained during the script preparation session, the Principal Investigator will compose "scripts" approximately 30 seconds in duration portraying each participant's combat events in their own words. Participants will then return for script-driven imagery testing sessions in the psychophysiology laboratory one week and six months later. During each of these sessions, they will undergo recording of heart rate, skin conductance, and corrugator and frontalis electromyogram during a baseline period. They will then listen to a recording of their traumatic scripts and be instructed to imagine the events portrayed as if they were happening again, while physiologic measures are recorded. Responses (change) scores for each physiologic variable for each session will be calculated by subtracting the preceding baseline period mean from the imagery period mean. The physiologic data will be analyzed by multivariate analysis of variance (MANOVA) followed by univariate ANOVAs. The hypothesis predicts that at each time period, the physiologic responses of the post-reactivation propranolol group will be significantly smaller than those of the non-reactivation propranolol group. Relevance: If a traumatic memory undergoes reconsolidation when reactivated, this could re-open the window of opportunity to influence the memory pharmacologically. This could have important implications for the treatment of PTSD. Should the proposed psychophysiologic study confirm that post-reactivation propranolol weakens traumatic combat memories, it would be a relatively short leap to clinical studies of the therapeutic efficacy of this novel modality. The consolidation of learning is enhanced by adrenalin and other stress hormones. This memory enhancing effect is opposed by propranolol. In posttraumatic stress disorder (PTSD), a psychologically traumatic event may overstimulate stress hormones such as adrenalin, which in turn overly strengthen consolidation of the memory of the event, leading to an excessively powerful and persistent memory. Administration of propranolol after a psychologically traumatic event could reduce subsequent PTSD. Unfortunately, there exists a window of opportunity for influencing the consolidation of a traumatic event into long-term memory. In persons who have already developed PTSD, this would have closed months or years earlier. However, recent developments in animal research suggest that reactivation (retrieval) of a consolidated memory can return it to a labile state, from which it must be restabilized in order to persist. This process, which has been termed "reconsolidation," can be reduced in animals by propranolol. In a preliminary study performed by the PI and colleagues in Canada, civilian participants with PTSD described the traumatic event during a script preparation session, which served to reactivate their traumatic memory. They then received either propranolol or placebo. A week later, during script-driven imagery of their traumatic events, physiologic responses were smaller in the participants who had received post-reactivation propranolol compared to placebo, suggesting that the traumatic memory had been weakened by the propranolol. These results suggest that that post-reactivation propranolol recapitulates its effects on consolidation, this time by blocking reconsolidation of the traumatic memory. Several important questions remain unanswered. First, does propranolol also weaken traumatic memories in combat-related PTSD? Second, does this weakening effect only occur when the propranolol is given after combat memory reactivation? If not, this would refute the reconsolidation hypothesis and suggest that propranolol affects non-specific mechanisms. Third, how long does the traumatic memory weakening last? The proposed project will investigate these questions by performing an improved, double-blind, placebo-controlled study in Iraq and Afghanistan veterans with combat-related PTSD. Participants will be randomly assigned to one of two groups: post-reactivation propranolol or non-reactivation propranolol. Participants in the non-reactivation propranolol group will receive propranolol in the absence of traumatic memory reactivation. Participants randomized to the post-reactivation propranolol group will receive matching placebo capsules. Two days later, all participants will return for a script preparation session, at which time they will describe the details of their traumatic event. Participants randomized to the post-reactivation propranolol group will then receive propranolol, whereas participants randomized to the non-reactivation propranolol group will receive placebo. Participants will then return for psychophysiologic script-driven imagery testing one week and six months later. We hypothesize that those who receive propranolol after reactivation of their memories of their traumatic combat event(s) will show significantly smaller psychophysiologic responses during script-driven imagery testing compared to participants who receive propranolol in the absence of combat memory reactivation, supporting the inference that post-reactivation propranolol blocks the reconsolidation of traumatic combat memories.