Low platelet-poor plasma concentrations of serotonin in patients with combat-related posttraumatic stress disorder

Ventral Tegmental Area Dysfunction and Disruption of Dopaminergic Homeostasis: Implications for Post-traumatic Stress Disorder

Post-traumatic stress disorder (PTSD) is a debilitating psychiatric condition characterized by intrusive recollections of the traumatic event, avoidance behaviors, hyper-arousal to event-related cues, cognitive disruption, and mood dysregulation. Accumulating preclinical and clinical evidence implicates dysfunction of the ventral tegmental area (VTA) dopaminergic system in PTSD pathogenesis. This article reviews recent advances in our knowledge of the relationship between dopaminergic dyshomeostasis and PTSD, including the contributions of specific dopaminergic gene variants to disease susceptibility, alterations in VTA dopamine neuron activity, dysregulation of dopaminergic transmission, and potential pharmacological and psychological interventions for PTSD targeting the dopaminergic system. An in-depth understanding of PTSD etiology is crucial for the development of innovative risk assessment, diagnostic, and treatment strategies following traumatic events.

Altered reward-related neural responses in non-manifesting carriers of the Parkinson disease related LRRK2 mutation

Disturbances in reward processing occur in Parkinson's disease (PD) however it is unclear whether these are solely drug-related. We applied an event-related fMRI gambling task to a group of non-manifesting carriers (NMC) of the G2019S mutation in the LRRK2 gene, in order to assess the reward network in an "at risk" population for future development of PD. Sixty-eight non-manifesting participants, 32 of which were non-manifesting non-carriers (NMNC), performed a gambling task which included defined intervals of anticipation and response to both reward and punishment in an fMRI setup. Behavior and cerebral activations were measured using both hypothesis driven and whole brain analysis. NMC demonstrated higher trait anxiety scores (p = 0.04) compared to NMNC. Lower activations were detected among NMC during risky anticipation in the left nucleus accumbens (NAcc) (p = 0.05) and during response to punishment in the right insula (p = 0.02), with higher activations among NMC during safe anticipation in the right insula (p = 0.02). Psycho-Physiological Interaction (PPI) analysis from the NAcc and insula revealed differential connectivity patterns. Whole brain analysis demonstrated divergent between-group activations in distributed cortical regions, bilateral caudate, left midbrain, when participants were required to press the response button upon making their next chosen move. Abnormal neural activity in both the reward and motor networks were detected in NMC indicating involvement of the ventral striatum regardless of medication use in "at risk" individuals for future development of PD.

Catecholamines in Post-traumatic Stress Disorder: A Systematic Review and Meta-Analysis

Studies on the association between post-traumatic stress disorder (PTSD) and levels of catecholamines have yielded inconsistent results. The aim of this study was to conduct a systematic review and meta-analysis to assess whether concentrations of the catecholamines dopamine, norepinephrine, and epinephrine are associated with PTSD. This study searched relevant articles in the following databases: PubMed, Embase, Web of Science, and Psyc-ARTICLES. Each database was searched from its inception to September, 2018. Data related to catecholamine concentrations were extracted for patients with PTSD and the controls to calculate standardized mean differences and to evaluate effect sizes. A meta-analysis was then performed to compare the concentration of each catecholamine between the two groups in blood and/or urine samples. Heterogeneity was quantified using I² and its significance was tested using the Q statistics. Subgroup analyses of the types of controls, PTSD assessment tools, and assayed methods used in the studies were performed to explore sources of heterogeneity among studies. Random-effects models were used to combine results from selected studies. A total of 1,388 articles were identified, of which 27 were included in the final analysis. Heterogeneity was high; hence random-effects models were used to combine results of selected studies. Results revealed significantly higher norepinephrine levels in people with PTSD than in the controls [standardized mean difference (SMD) = 0.35, 95% confidence interval (CI): 0.13 to 0.57, p = 0.002]. No difference was found in dopamine and epinephrine concentrations between the two groups. Elevated norepinephrine levels may be an important indicator for PTSD.

Reduced interleukin 1A gene expression in the dorsolateral prefrontal cortex of individuals with PTSD and depression

The inflammatory system has been implicated in the pathophysiology of a variety of psychiatric conditions. Individuals with PTSD, depression, and other fear- and anxiety-related disorders exhibit alterations in peripheral circulating inflammatory markers, suggesting dysregulation of the inflammatory system. The relationship between inflammation and PTSD has been investigated almost exclusively in the periphery, and has not been extensively explored in human postmortem brain tissue. Interleukins (ILs) represent a subtype of cytokines and are key signaling proteins in the immune and inflammatory systems. Based on prior research implicating IL signaling in PTSD and depression, we performed a preliminary investigation of IL gene expression in a region of the cortex involved in emotion regulation and PTSD, the dorsolateral prefrontal cortex (dlPFC), using tissue from the newly established VA National PTSD Brain Bank. Gene expression analyses were conducted on post-mortem tissue from the dlPFC from 50 donors: 13 controls, 12 PTSD cases, and 25 depressed cases. RNA was extracted from frozen dlPFC tissue, reverse transcribed to cDNA, and quantitative polymerase chain reaction (qPCR) was performed to assess gene expression of IL1A, IL1B, IL6, IL8, IL10, IL13, and IL15. We found a multiple-testing corrected significant decrease in IL1A expression in the dlPFC for PTSD and depression cases compared to controls (p < 0.005) with age at death, sex, race and RNA integrity number (RIN) included as covariates. To our knowledge this finding is the first demonstration of altered IL expression in brain tissue from deceased individuals with histories of PTSD and/or depression.

Biological markers for anxiety disorders, OCD and PTSD: A consensus statement. Part II: Neurochemistry, neurophysiology and neurocognition

OBJECTIVE

Biomarkers are defined as anatomical, biochemical or physiological traits that are specific to certain disorders or syndromes. The objective of this paper is to summarise the current knowledge of biomarkers for anxiety disorders, obsessive-compulsive disorder (OCD) and posttraumatic stress disorder (PTSD).

METHODS

Findings in biomarker research were reviewed by a task force of international experts in the field, consisting of members of the World Federation of Societies for Biological Psychiatry Task Force on Biological Markers and of the European College of Neuropsychopharmacology Anxiety Disorders Research Network.

RESULTS

The present article (Part II) summarises findings on potential biomarkers in neurochemistry (neurotransmitters such as serotonin, norepinephrine, dopamine or GABA, neuropeptides such as cholecystokinin, neurokinins, atrial natriuretic peptide, or oxytocin, the HPA axis, neurotrophic factors such as NGF and BDNF, immunology and CO2 hypersensitivity), neurophysiology (EEG, heart rate variability) and neurocognition. The accompanying paper (Part I) focuses on neuroimaging and genetics.

CONCLUSIONS

Although at present, none of the putative biomarkers is sufficient and specific as a diagnostic tool, an abundance of high quality research has accumulated that should improve our understanding of the neurobiological causes of anxiety disorders, OCD and PTSD.

The dopaminergic response to acute stress in health and psychopathology: A systematic review

Previous work in animals has shown that dopamine (DA) in cortex and striatum plays an essential role in stress processing. For the first time, we systematically reviewed the in vivo evidence for DAergic stress processing in health and psychopathology in humans. All studies included (n studies=25, n observations=324) utilized DA D2/3 positron emission tomography and measured DAergic activity during an acute stress challenge. The evidence in healthy volunteers (HV) suggests that physiological, but not psychological, stress consistently increases striatal DA release. Instead, increased medial prefrontal cortex (mPFC) DAergic activity in HV was observed during psychological stress. Across brain regions, stress-related DAergic activity was correlated with the physiological and psychological intensity of the stressor. The magnitude of stress-induced DA release was dependent on rearing conditions, personality traits and genetic variations in several SNPs. In psychopathology, preliminary evidence was found for stress-related dorsal striatal DAergic hyperactivity in psychosis spectrum and a blunted response in chronic cannabis use and pain-related disorders, but results were inconsistent. Physiological stress-induced DAergic activity in striatum in HV may reflect somatosensory properties of the stressor and readiness for active fight-or-flight behavior. DAergic activity in HV in the ventral striatum and mPFC may be more related to expectations about the stressor and threat evaluation, respectively. Future studies with increased sample size in HV and psychopathology assessing the functional relevance of stress-induced DAergic activity, the association between cortical and subcortical DAergic activity and the direct comparison of different stressors are necessary to conclusively elucidate the role of the DA system in the stress response.

Monoamine-sensitive developmental periods impacting adult emotional and cognitive behaviors

Development passes through sensitive periods, during which plasticity allows for genetic and environmental factors to exert indelible influence on the maturation of the organism. In the context of central nervous system development, such sensitive periods shape the formation of neurocircuits that mediate, regulate, and control behavior. This general mechanism allows for development to be guided by both the genetic blueprint as well as the environmental context. While allowing for adaptation, such sensitive periods are also vulnerability windows during which external and internal factors can confer risk to disorders by derailing otherwise resilient developmental programs. Here we review developmental periods that are sensitive to monoamine signaling and impact adult behaviors of relevance to psychiatry. Specifically, we review (1) a serotonin-sensitive period that impacts sensory system development, (2) a serotonin-sensitive period that impacts cognition, anxiety- and depression-related behaviors, and (3) a dopamine- and serotonin-sensitive period affecting aggression, impulsivity and behavioral response to psychostimulants. We discuss preclinical data to provide mechanistic insight, as well as epidemiological and clinical data to point out translational relevance. The field of translational developmental neuroscience has progressed exponentially providing solid conceptual advances and unprecedented mechanistic insight. With such knowledge at hand and important methodological innovation ongoing, the field is poised for breakthroughs elucidating the developmental origins of neuropsychiatric disorders, and thus understanding pathophysiology. Such knowledge of sensitive periods that determine the developmental trajectory of complex behaviors is a necessary step towards improving prevention and treatment approaches for neuropsychiatric disorders.

Higher striatal dopamine transporter density in PTSD: an in vivo SPECT study with [(99m)Tc]TRODAT-1

RATIONALE

Some evidence suggests a hyperdopaminergic state in posttraumatic stress disorder (PTSD). The 9-repetition allele (9R) located in the 3' untranslated region of the dopamine transporter (DAT) gene (SLC6A3) is more frequent among PTSD patients. In vivo molecular imaging studies have shown that healthy 9R carriers have increased striatal DAT binding. However, no prior study evaluated in vivo striatal DAT density in PTSD.

OBJECTIVES

The objective of this study was to evaluate in vivo striatal DAT density in PTSD.

METHODS

Twenty-one PTSD subjects and 21 control subjects, who were traumatized but asymptomatic, closely matched comparison subjects evaluated with the Clinician-Administered PTSD Scale underwent a single-photon emission computed tomography scan with [(99m)TC]-TRODAT-1. DAT binding potential (DAT-BP) was calculated using the striatum as the region of the interest and the occipital cortex as a reference region.

RESULTS

PTSD patients had greater bilateral striatal DAT-BP (mean ± SD; left, 1.80 ± 0.42; right, 1.78 ± 0.40) than traumatized control subjects (left, 1.62 ± 0.32; right, 1.61 ± 0.31; p = 0.039 for the left striatum and p = 0.032 for the right striatum).

CONCLUSIONS

These results provide the first in vivo evidence for increased DAT density in PTSD. Increases in DAT density may reflect higher dopamine turnover in PTSD, which could contribute to the perpetuation and potentiation of exaggerated fear responses to a given event associated with the traumatic experience. Situations that resemble the traumatic event turn to be interpreted as highly salient (driving attention, arousal, and motivation) in detriment of other daily situations.

In vitro mutagenicity and blood compatibility of paclitaxel and curcumin in poly (DL-lactide-co-glicolide) films

Curcumin is considered to be a potential component for drug-eluting stents due to its anti-inflammatory properties. In this study we compared the mutagenicity and blood compatibility of curcumin to first generation drug eluting stent components: paclitaxel and sirolimus. The Ames test was used to assess mutagenicity. Blood compatibility was tested by measuring platelet activation and fibrinogen adsorption on poly (DL-lactide-co-glycolide, PLGA) films. We discovered that there was no significant increase in the number of revertants/plate following treatment with curcumin (up to 0.5mg/plate) or sirolimus (up to 0.5 μg/plate). However, a significant induction in the frequency of bacterial his(+) revertant colonies by paclitaxel at concentrations of 0.02, 0.05, 0.1, 0.2 and 0.5 μg/plate was observed. We also discovered a significant reduction in platelet activation by PLGA films containing 30% and 50% by weight curcumin. A similar reduction in platelet activation was also observed for PLGA films containing 1% by weight paclitaxel. In addition, we observed an increase of fibrinogen adsorption to PLGA-films containing curcumin. This would compromise the potential use of curcumin as a component of drug-eluting stents. Moreover, our data challenges the current view that paclitaxel does not significantly induce mutagenesis.

P11: a potential biomarker for posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) is a chronic and disabling anxiety disorder that occurs after a traumatic event. It is associated with an increased risk of suicide and marked deficits in social and occupational functioning. Currently, the diagnosis for PTSD is established on the basis of a patient's clinical history, mental status examination, duration of symptoms, and clinician administered symptom checklist or patient self-report. However, there are no available laboratory biomarker tests for PTSD. To begin intervention at the earliest possible time, priority must be given to developing objective approaches to determine the presence of PTSD. Thus, using cutting-edge technology and skill to develop a simple blood test or a biomarker to detect PTSD at its earliest and most treatable stage would benefit both physician and patient. Several technologies and skills have been used in the identification biomarker research. We discuss three major methods in this chapter (blood RNA and DNA purification, chromatin immunoprecipitation, and Western blot), which have been used in our study to determine whether p11 is a potential biomarker for PTSD. Using these procedures will not only enhance the study of the molecular mechanisms of PTSD but also help the translation of basic science to a clinical setting.

The Measurement of Platelet-Poor Plasma Serotonin: A Systematic Review of Prior Reports and Recommendations for Improved Analysis

BACKGROUND

Recent reports of new and important roles for serotonin (5-hydroxytryptamine, 5-HT) in the periphery have substantially increased interest in measuring peripheral serotonin. Nearly all circulating serotonin is found within platelets and this pool has been assessed by measuring serotonin in whole blood or in platelet-rich plasma. Measurement of the much smaller but potentially critically important pool of human free plasma serotonin in platelet-poor plasma (PPP) has proven much more difficult, with a wide range of reference values reported.

CONTENT

To characterize the available data we carried out a systematic literature search of previous reports of PPP serotonin and attempted to determine the best estimate of true PPP serotonin concentration in humans. A total of 101 published reports that included PPP serotonin values in healthy controls were found and included in the summary statistical analyses. The distribution of PPP serotonin values demonstrated high skewness (+1.98), and the reported values ranged from 0.6 to 179 nmol/L, with a mean of 31.6 nmol/L, an SD of 38.9 nmol/L, and a median of 14.8 nmol/L.

SUMMARY

Reported concentrations for human PPP or free plasma serotonin were highly discrepant, with most reports giving erroneously high values that should be disregarded. Inherent difficulties in selectively measuring the extremely low concentrations of serotonin present in PPP and in preparing PPP without contamination from platelet-derived serotonin contributed to the problem, as did the failure of researchers to compare their results with those from prior studies. There is a clear and pressing need for reference materials for the measurement of plasma (PPP) serotonin.

Exaggerated platelet reactivity to physiological agonists in war veterans with posttraumatic stress disorder

An association between traumatic stress and cardiovascular disease (CVD) is supported by various epidemiological studies. Platelet activation and binding of activated platelets to leukocytes contributes to the pathophysiology of CVD. Evidence of hyperactive sympathetic nervous system, altered expression of platelet α(2)-adrenoreceptors (α(2)AR), and altered platelet adenylate cyclase activity in patients with posttraumatic stress disorder (PTSD) suggest that platelet reactivity in PTSD may be altered as well. We tested whether platelet reactivity to increasing doses of adenosine-diphosphate (ADP), epinephrine (EPI), or their combination differs between war veterans with PTSD (n=15) and healthy controls (n=12). For this purpose, citrated whole blood was incubated with increasing concentrations of ADP (0.1, 1, 10 μM), EPI alone (10 nM, 100 nM, 1000 nM), or EPI (10 nM, 100 nM, 1000 nM) in combination with 0.1 μM ADP. A subset of samples was also incubated with 10 μM yohimbine (YOH), α(2)AR antagonist, to distinguish receptor-specific effects. Platelet CD62P expression and formation of platelet-leukocyte aggregates (PLA) [platelet-monocyte (P-Mo), -lymphocyte (P-Ly), and -neutrophil (P-Ne) aggregates] were measured using three-color flow cytometry. Platelet reactivity was higher in war veterans with PTSD when compared to controls, as determined by greater CD62P expression and formation of PLA in response to ADP alone or in combination with EPI. Platelet reactivity also correlated with the severity of PTSD symptoms. Preliminary experiments with YOH indicate that stress-associated EPI elevations may contribute to platelet activation through a α(2)AR-dependent mechanism. The enhanced platelet reactivity observed in our study may be the underlying mechanism contributing to the development of CVD in PTSD patients.

Posttraumatic stress disorder in children and adolescents: a review of psychopharmacological treatment

PTSD in children and adolescents differs from the adult disease. Therapeutic approaches involve both psychotherapy and psychopharmacotherapy.

OBJECTIVES

The current paper aims at reviewing studies on psychopharmacological treatment of childhood and adolescent PTSD. Additionally, developmental frameworks for PTSD diagnosis and research along with an experimental model of quenching and kindling in the context of stress exposure are presented. We conducted an extensive literature search of reviews on psychopharmacotherapy as well as studies on psychopharmacological treatment for PTSD among children and adolescents. We used the database PubMed and focused on the time period of the last 10 years up to January 2009. Pertinent earlier papers were also included.There are a limited number of studies specifically assessing the psychopharmacological treatment of PTSD in children and adolescents. The vast majority of them lack verification in RCTs. Only the use of imipramine, divalproex sodium and sertraline were already evaluated in RCTs. Future studies should take into account developmental approaches to the diagnosis and treatment of PTSD in children and adolescents. In this context, different underlying neurobiological patterns, which are reflected in distinct clinical symptomatology, require a precise investigation and a symptom-orientated psychopharmacological approach.

Gene-environment interaction in posttraumatic stress disorder: review, strategy and new directions for future research

The purpose of this article is to encourage research investigating the role of measured gene-environment interaction (G x E) in the etiology of posttraumatic stress disorder (PTSD). PTSD is uniquely suited to the study of G x E as the diagnosis requires exposure to a potentially-traumatic life event. PTSD is also moderately heritable; however, the role of genetic factors in PTSD etiology has been largely neglected both by trauma researchers and psychiatric geneticists. First, we summarize evidence for genetic influences on PTSD from family, twin, and molecular genetic studies. Second, we discuss the key challenges in G x E studies of PTSD and offer practical strategies for addressing these challenges and for discovering replicable G x E for PTSD. Finally, we propose some promising new directions for PTSD G x E research. We suggest that G x E research in PTSD is essential to understanding vulnerability and resilience following exposure to a traumatic event.

Extended-release formulation of venlafaxine in the treatment of post-traumatic stress disorder

There is abundant evidence for abnormalities of both norepinephrine and serotonin neurotransmitter systems in post-traumatic stress disorder (PTSD). Venlafaxine extended-release formulation (venlafaxine XR) is a serotonin and norepinephrine re-uptake inhibitor with antidepressant and anxiolytic properties relevant to the pathophysiology of PTSD. Venlafaxine XR is currently approved for the treatment of panic disorder, generalized anxiety disorder and social anxiety disorder, as well as major depression in adults, based on a number of randomized, double blind, placebo-controlled clinical trials. Limited data also demonstrate that venlafaxine XR maintains a therapeutic response for more than 6 months in these anxiety disorders. Venlafaxine XR has demonstrated short- and long-term efficacy for the treatment of PTSD in two recent randomized, double-blind, placebo-controlled clinical trials, although it has not been extensively studied for PTSD, compared with other anxiety disorders. This review focuses on the potential role of venlafaxine XR in the treatment of PTSD, based on currently available evidence.

Endocrine and inflammatory alterations in post-traumatic stress disorder

Post-traumatic stress disorder has frequently been found associated with alterations in endogenous stress hormone systems, for example the hypothalamus-pituitary-adrenal axis and sympatho-adrenal-medullary system. Hormonal alterations are observed at the central and peripheral level of the central nervous system, and in the periphery for inflammatory disinhibition. Both consequences bear significant hazards for the individual, the former by sustaining or exacerbating the psychiatric condition, the latter by its detrimental effects on somatic health. However, the role of hormonal modifications in the development and maintenance of post-traumatic stress disorder symptoms and in the accompanying cognitive and emotional impairments still remains quite unclear.

Alterations in stress reactivity after long-term treatment with paroxetine in women with posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) is typically accompanied by both acute and chronic alterations in the stress response. These alterations have mostly been described in individuals under baseline conditions, but studies have also used a challenge model to assess the role of the hypothalamic-pituitary-adrenal (HPA) axis in the stress response. The purpose of this article was to assess the effect of long-term treatment with the selective reuptake inhibitor (SSRI), paroxetine, on stress reactivity in patients with PTSD. We assessed diurnal salivary cortisol and urinary cortisol as well as cortisol, heart rate, and behavioral responses to a standardized cognitive stress challenge, in 13 female patients with chronic PTSD before and after 12 months of paroxetine treatment. Treatment resulted in a significant decrease in PTSD symptoms. Twenty-four-hour urinary cortisol was lower compared to base line after successful treatment. Treatment resulted in a decrease of salivary cortisol levels on all time points on a diurnal curve. Despite similar stress perception, cortisol response to the cognitive stress challenge resulted in a 26.5% relative decrease in stress-induced salivary cortisol with treatment. These results suggest that successful treatment with SSRI in chronic PTSD is associated with a trend for a decrease in baseline diurnal cortisol and with reduced cortisol reactivity to stress.

Reboxetine versus fluvoxamine in the treatment of motor vehicle accident-related posttraumatic stress disorder: a double-blind, fixed-dosage, controlled trial

BACKGROUND

Motor vehicle accidents (MVAs) are a leading cause of posttraumatic stress disorder (PTSD) in the general population. Alterations in norepinephrine and serotonin systems have been proposed as mechanisms involved in the pathophysiology of the condition, with treatment directed at these neurotransmitter systems. Reboxetine, a selective norepinephrine reuptake inhibitor, exhibits high affinity and selectivity for the human norepinephrine transporter. Inasmuch as PTSD may be associated with dysregulation of noradrenergic activity, the present double-blind randomized clinical trial intended to evaluate reboxetine's efficacy in the management of MVA-related PTSD and to compare its efficacy with a medication commonly used in PTSD, the selective serotonin reuptake inhibitor fluvoxamine.

METHODS

Forty patients with MVA-related PTSD attending a local community mental health outpatient clinic were randomized to receive a fixed dose of either reboxetine (8 mg/d) or fluvoxamine (150 mg/d) in a double-blind fashion for a period of 8 weeks.

RESULTS

At baseline and at study end point, the 2 subgroups demonstrated no statistical differences in scores on PTSD, depression, and anxiety rating scales. Both medications led to significant improvements in all clinical scales measured. Nine patients receiving reboxetine and 3 receiving fluvoxamine withdrew from the study because of side effects.

CONCLUSIONS

Study observations indicate comparable efficacy of reboxetine and fluvoxamine in the management of MVA-related PTSD despite reboxetine's selective noradrenergic activity. Reboxetine appears to be at least as effective as fluvoxamine and may offer an alternative management option in this often difficult-to-treat and disabling condition. A lower and flexible reboxetine dosing schedule will be recommended for future research to improve its tolerability in PTSD patients.

The auditory startle response in post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) patients are considered to have excessive EMG responses in the orbicularis oculi (OO) muscle and excessive autonomic responses to startling stimuli. The aim of the present study was to gain more insight into the pattern of the generalized auditory startle reflex (ASR). Reflex EMG responses to auditory startling stimuli in seven muscles rather than the EMG response of the OO alone as well as the psychogalvanic reflex (PGR) were studied in PTSD patients and healthy controls. Ten subjects with chronic PTSD (>3 months) and a history of excessive startling and 11 healthy controls were included. Latency, amplitude and duration of the EMG responses and the amplitude of the PGR to 10 auditory stimuli of 110 dB SPL were investigated in seven left-sided muscles. The size of the startle reflex, defined by the number of muscles activated by the acoustic stimulus and by the amplitude of the EMG response of the OO muscle as well, did not differ significantly between patients and controls. Median latencies of activity in the sternocleidomastoid (SC) (patients 80 ms; controls 54 ms) and the deltoid (DE) muscles (patients 113 ms; controls 69 ms) were prolonged significantly in PTSD compared to controls (P < 0.05). In the OO muscle, a late response (median latency in patients 308 ms; in controls 522 ms), probably the orienting reflex, was more frequently present in patients (56%) than in controls (12%). In patients, the mean PGR was enlarged compared to controls (P < 0.05). The size of the ASR response is not enlarged in PTSD patients. EMG latencies in the PTSD patients are prolonged in SC and DE muscles. The presence of a late response in the OO muscle discriminates between groups of PTSD patients with a history of startling and healthy controls. In addition, the autonomic response, i.e. the enlarged amplitude of the PGR can discriminate between these groups.

Cortical/hippocampal monoamines, HPA-axis changes and aversive behavior following stress and restress in an animal model of post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is characterized by monoaminergic and hypothalamic-pituitary-adrenal (HPA)-axis abnormalities. Understanding monoamine-HPA-axis responses following stress and restress may provide a greater understanding of the neurobiology of PTSD and of its treatment. Hippocampal and frontal cortex serotonin, noradrenaline and dopamine, plasma corticosterone and aversive behavior were studied in rats on day 1 and day 7 post acute stress (AS = sequential restraint stress, swim stress and halothane exposure), and on day 1 and day 7 post restress (RS = swim stress). After AS, there was an early increase in both avoidant behavior and corticosterone (1 h after stress), with subsequent normalisation (day 7), suggesting an adequate adaptive response to the stressor. However, restress (RS) evoked a significant early HPA-axis hyporesponsiveness (1 h after RS) and a later significant increase in avoidant behavior on day 7 post RS. Hippocampal serotonin, noradrenaline and dopamine concentrations were unchanged 1 h post AS, but were significantly raised on day 7 post AS. Restress, however, reduced serotonin and noradrenaline levels 1 h after and on day 7 post RS, respectively, while dopamine was unchanged. In the frontal cortex only dopamine levels were altered, being significantly elevated 1 h after AS, and reduced on day 7 post RS. AS and RS thus differently effect the HPA-axis, evoking regional-specific brain monoamine changes that underlie maladaptive behavior and other post stress-related sequelae.

Influence of the serotonin transporter promoter gene polymorphism on susceptibility to posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) is a prevalent anxiety disorder marked by behavioral, physiologic, and hormonal alterations. The etiology of PTSD is unknown, although exposure to a traumatic event constitutes a necessary, but not sufficient, factor. Serotonergic dysfunction has been implicated in PTSD. The present study examined the possible association between the serotonin-transporter-linked polymorphic region (SERTPR) and PTSD. The genotype and allele frequencies of the SERTPR were analyzed in 100 PTSD patients and 197 unrelated healthy controls using a case-control design. The frequency of the s/s genotype was significantly higher in PTSD patients than in normal controls. These findings suggest that the SERTPR s/s genotype is one of the genetic factors for the susceptibility to PTSD. Further investigations are required into the influence of gene polymorphisms on the biological mechanisms of PTSD, its clinical expression, and its response to treatment.

Low brain-derived neurotrophic factor (BDNF) levels in serum of depressed patients probably results from lowered platelet BDNF release unrelated to platelet reactivity

BACKGROUND

Recent reports have suggested a role for brain-derived neurotrophic factor (BDNF) in psychiatric disorders. Decreased serum BDNF levels have been reported in major depression, but the cause of this decrease has not yet been investigated. The goal of this study was to assess blood BDNF and a platelet activation index, PF4.

METHODS

Forty-three drug-free patients (27 female, 16 male) diagnosed with major depression and 35 healthy control subjects (18 female, 17 male) were assessed for plasma, serum, and blood BDNF content. Brain-derived neurotrophic factor and PF4 were assayed with enzyme-linked immunosorbent assay methods, and severity of depression was evaluated with the Montgomery-Asberg Depression Rating Scale.

RESULTS

Serum and plasma BDNF levels were decreased in depressed patients compared with control subjects. In whole blood, BDNF levels were unaltered in the depressed subjects compared with control subjects. The serum/blood BDNF ratio was lower in patients with major depression. Increased plasma but not serum PF4 levels were observed in depressed subjects compared with control subjects.

CONCLUSIONS

Our results suggest that an alteration of serum or plasma BDNF is not due to the change in blood BDNF but rather is probably related to mechanisms of BDNF release. Secretion of BDNF seems to be independent of platelet reactivity; other mechanisms are therefore probably involved and need to be elucidated.

Adaptive and maladaptive psychobiological responses to severe psychological stress: implications for the discovery of novel pharmacotherapy

Post-traumatic stress disorder (PTSD) is one of the few DSM-IV diagnoses contingent upon a psychosocial stressor. In this context, there is an urgent need to acquire a better understanding of both the adaptive and maladaptive psychobiological responses to traumatic stress. Preclinical investigators have utilized a variety of animal models to identify the behavioral and neurobiological features of the organism's response to stress. However, given the complexity of the healthy and pathological human response to physiological and psychological stress, the extent to which the animal data is immediately transferable to human remains to be fully determined. This review draws upon preclinical and clinical literature to examine the transformation of an adaptive human stress response into a maladaptive and debilitating mental disorder. An integrative psychobiological model for PTSD is presented, linking psychological processes and behavioral patterns with current findings in neurocircuitry, neurochemistry and psychophysiology. The implications of this model for the discovery of novel pharmacological approaches to the treatment of severe psychological distress are discussed.

The role of psychosocial factors in the progression of hepatocellular carcinoma

The number of deaths per year from hepatocellular carcinoma (HCC) exceeds 250000, placing it sixth as the cause of death from cancer worldwide. The primary etiology of most cases of HCC in the US is hepatitis B and/or C. Extensive research has demonstrated that the relationship between hepatitis B infection and the progression to HCC is mediated by the immune system. A substantial, but unrelated literature, describes the relationship between psychosocial factors (e.g., stress, psychiatric morbidity), immune system reactivity, and disease progression in patients with cancer. However, the role of these factors in the progression of HBV-HCC has not been explored. An understanding of the relationship among virology, immunology, and behavior in the development and recurrence of HCC may provide alternative methods for secondary prevention of HCC (e.g., behavioral) until a vaccine and/or pharmacological treatments are developed, feasible, and affordable.

Platelet 5-HT concentration and comorbid depression in war veterans with and without posttraumatic stress disorder

BACKGROUND

The serotonergic system is implicated in the pathophysiology of posttraumatic stress disorder (PTSD) and depression. The present study focused on platelet serotonin (5-HT) concentration and symptoms of comorbid depression in war veterans with or without PTSD.

METHODS

PTSD and depression were evaluated using Clinician Administered PTSD Scale, Davidson Trauma Scale, Montgomery-Asberg Depression Rating Scale and Hamilton Anxiety Scale. Sixty-five male drug-free war veterans (48 with PTSD and 17 without PTSD) and 65 age- and sex-matched healthy controls were studied.

RESULTS

Comorbid depression occurred in 54 and 31% of war veterans with PTSD and without PTSD, respectively. Platelet 5-HT concentration was similar in the groups of depressed and nondepressed war veterans with or without PTSD and healthy controls. Platelet 5-HT concentration was found to differ between war veterans with various degrees of appetite loss. A positive correlation was observed between platelet 5-HT concentration and severity of appetite loss in veterans with PTSD. There was no relationship between platelet 5-HT concentration and severity of other symptoms of PTSD or depression.

LIMITATIONS

War veterans included in the study were outpatients.

CONCLUSIONS

War veterans with PTSD had a high incidence of comorbid depression, that was not related to platelet 5-HT concentration. The marked relationship between platelet 5-HT concentration and severity of appetite loss, suggested that 5-HT system is involved in the regulation of appetite, at least in depressed war veterans with PTSD.

Biologic findings of post-traumatic stress disorder and child maltreatment

Child maltreatment is a serious problem in US society, affecting approximately three million children. Children and adolescents exposed to child abuse and neglect experience high rates of post-traumatic stress disorder (PTSD). In addition, they are at risk for comorbid mental illness. Biologic stress systems affected in trauma and in PTSD are complex. Findings in cognitive testing, neuroimaging, and affected pathways shed light on the consequences of child maltreatment. What is known about treatment and outcomes for children with history of maltreatment and maltreatment-related PTSD indicates the need for prevention, intervention, and treatment of children exposed to abuse and neglect. The following is a brief review of the most recent neurobiologic findings in child maltreatment and related PTSD.

Lower cortisol levels in depressed patients with comorbid post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is often comorbid with major depressive episodes (MDEs) and both conditions carry a higher rate of suicidal behavior. Hypothalamic-pituitary-adrenal (HPA) axis and serotonin abnormalities are associated with both conditions and suicidal behavior, but their inter-relation is not known. We determined cortisol response to placebo or fenfluramine in MDE, MDE and PTSD (MDE+PTSD), and healthy volunteers (HVs) and examined the relation of cortisol responses to suicidal behavior. A total of 58 medication-free patients with MDE (13 had MDE+PTSD) and 24 HVs were studied. They received placebo on the first day and fenfluramine on the second day. Cortisol levels were drawn before challenge and for 5 h thereafter. The MDE+PTSD group had the lowest plasma cortisol, the MDE group had the highest, and HVs had intermediate levels. There were no group differences in cortisol response to fenfluramine. Suicidal behavior, sex, and childhood history of abuse were not predictors of baseline or postchallenge plasma cortisol. Cortisol levels increased with age. This study finds elevated cortisol levels in MDE and is the first report of lower cortisol levels in MDE+PTSD. The findings underscore the impact of comorbidity of PTSD with MDE and highlight the importance of considering comorbidity in psychobiology.

Association between the dopamine transporter gene and posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) is a chronic anxiety disorder that follows exposure to extreme events. A large twin study of Vietnam veterans had demonstrated a significant genetic contribution to chronic PTSD upon exposure to combat.(1,2) The underlying genes, however, have not been described. Given previous findings of abnormal dopamine (DA) function in PTSD, and given the putative effect of dopamine neurotransmission in shaping the responses to stress in animals, this study examined the association of the dopamine transporter (DAT) SLC6A3 3' variable number tandem repeat (VNTR) polymorphism with PTSD. The study evaluated 102 chronic PTSD patients and 104 carefully-documented trauma survivors (TS) who did not develop PTSD. Significant excess of 9 repeat allele was observed among PTSD patients (43% vs 30.5% in TS controls; chi(2) = 6.3, df = 1, P = 0.012). An excess of 9 repeat homozygous genotype was also observed in PTSD (20.43% in PTSD vs 9.47% in TS controls; chi(2) = 6.11, df = 2, P < 0.047). These findings suggest that genetically determined changes in dopaminergic reactivity may contribute to the occurrence of PTSD among trauma survivors.

Simultaneous determination of norepinephrine, serotonin, and 5-hydroxyindole-3-acetic acid in microdialysis samples from rat brain by microbore column liquid chromatography with fluorescence detection following derivatization with benzylamine

A microbore column liquid chromatographic method for the simultaneous determination of norepinephrine (NE), serotonin (5-HT), and 5-hydroxyindole-3-acetic acid (5HIAA) in microdialysis samples from rat brain is described. The method is based on precolumn derivatization of NE, 5HT, and 5HIAA with benzylamine in the presence of potassium hexacyanoferrate(III) resulting in the corresponding highly fluorescent and stable benzoxazole derivatives. A 15-microl sample was mixed with 15 microl derivatization reagent solution containing 0.3M 3-cyclohexylaminopropanesulfonic acid buffer (pH 12.0), 0.5M benzylamine, 10mM potassium hexacyanoferrate(III), and methanol (1/1/1/12, v/v/v/v). The derivatization was carried out at 50 degrees C for 20 min. The benzylamine derivatives of NE, 5HT, and 5HIAA were separated on a reversed-phase column (100 x 1.0mm i.d., packed with C18 silica, 5 microm) within 30 min. The mobile phase consisted of 15 mM acetate buffer (pH 5.0) and acetonitrile (31%, v/v); the flow rate was 50 microl/min. The detection limits (signal-to-noise ratio of 3) for NE, 5HT, and 5HIAA in the injection volume of 20 microl were 90, 210, and 260 amol, respectively. Microdialysis samples were collected in 7.5-min intervals from the probes implanted in the hippocampus and prefrontal cortex of awake rats. The basal levels of NE, 5HT, and 5HIAA in the dialysates from the hippocampus were 4.2+/-0.5, 4.9+/-0.6, and 934.1 +/- 63.4 fmol/20 microl, and those from the prefrontal cortex were 6.0+/-1.2,5.51.3, and 669.1 +/- 96.0 fmol/20 microl (mean +/- SE, n=25), respectively. The NE and 5HT levels were altered by perfusion of high-potassium or low-calcium solution and following antidepressant drugs imipramine and desipramine. It is concluded that the new fluorescence derivatization method in combination with microbore column liquid chromatography allows the simultaneous determination of NE, 5HT, and 5HIAA in the microdialysis samples at higher sensitivity, providing easier maintenance in routine use than that achieved by high-performance liquid chromatographic methods with electrochemical detection.

Circuits and systems in stress. II. Applications to neurobiology and treatment in posttraumatic stress disorder

This paper follows the preclinical work on the effects of stress on neurobiological and neuroendocrine systems and provides a comprehensive working model for understanding the pathophysiology of posttraumatic stress disorder (PTSD). Studies of the neurobiology of PTSD in clinical populations are reviewed. Specific brain areas that play an important role in a variety of types of memory are also preferentially affected by stress, including hippocampus, amygdala, medial prefrontal cortex, and cingulate. This review indicates the involvement of these brain systems in the stress response, and in learning and memory. Affected systems in the neural circuitry of PTSD are reviewed (hypothalamic-pituitary-adrenal axis (HPA-axis), catecholaminergic and serotonergic systems, endogenous benzodiazepines, neuropeptides, hypothalamic-pituitary-thyroid axis (HPT-axis), and neuro-immunological alterations) as well as changes found with structural and functional neuroimaging methods. Converging evidence has emphasized the role of early-life trauma in the development of PTSD and other trauma-related disorders. Current and new targets for systems that play a role in the neural circuitry of PTSD are discussed. This material provides a basis for understanding the psychopathology of stress-related disorders, in particular PTSD.

Psychopharmacological treatment in PTSD: a critical review

INTRODUCTION

Posttraumatic stress disorder (PTSD) is a prevalent psychiatric disorder that is heterogeneous in its nature, and often presents with other psychiatric comorbidities. As a result, empirical research on effective pharmacotherapy for PTSD has produced complex findings. This article reviews the existing research literature on pharmacological treatments for PTSD, identifies the most effective treatments, and where possible examines their mechanism of action with respect to the neurobiology of PTSD.

METHODS

We examined reports of clinical trials of psychotropic agents carried out with PTSD patients and published in peer-reviewed journals, as well as reports from presentations at scientific meetings between 1966 and 2001.

RESULTS

Numerous medications are effective in treating PTSD. These include tricyclic antidepressants, monoamine oxidase inhibitors, and serotonin reuptake inhibitors. Considering reported overall efficacy and side effects profiles, selective serotonin reuptake inhibitors emerge as the preferred first line treatment for PTSD. Mood stabilizers, atypical neuroleptics, adrenergic agents, and newer antidepressants also show promise, but require further controlled trials to clarify their place in the pharmacopoeia for PTSD.

DISCUSSION

There is clear evidence for effective pharmacotherapy of PTSD. Future improvements in the treatment of this disorder await further clinical trials and neurobiological research.

Platelet serotonergic markers in posttraumatic stress disorder

The neurobiological basis of posttraumatic stress disorder (PTSD) is believed to involve alterations in different neurotransmitter systems, and recent studies elucidated the role of serotonin (5-hydroxytryptamine, 5-HT) in PTSD. The data on the role of 5-HT have been obtained using blood platelets as a peripheral model for central serotonergic neurons. The reports suggested that platelet 5-HT concentration and monoamine oxidase (MAO) activity might serve as biological, even trait, markers for particular mental disturbances. Since the data on the peripheral serotonergic markers in PTSD subjects are controversial, the aim of the study was to determine platelet 5-HT concentration and platelet MAO activity in war veterans with PTSD, war veterans who did not develop PTSD, and in war veterans who were prisoners of war and developed PTSD. Platelet 5-HT concentration and MAO activity did not differ significantly between war veterans with or without PTSD, and prisoners of war with PTSD. Clinician-Administered PTSD Scale (CAPS) scores did not differ between war veterans with PTSD and prisoners of war, but Montgomery-Asberg Depression Rating Scale (MADRS) scores were significantly higher in prisoners of war who developed PTSD than in war veterans with PTSD. There was no significant correlation between platelet 5-HT concentration or platelet MAO activity and CAPS or MADRS scores within these groups. Platelet 5-HT concentration was slightly higher and platelet MAO activity slightly lower in prisoners of war with PTSD, than in all other groups. These findings suggest that platelet 5-HT concentration and platelet MAO activity are not altered in three drug-free groups--war veterans who did or did not develop PTSD, or in prisoners of war with PTSD--and that these platelet serotonergic markers are not associated with symptoms of PTSD or comorbid depression.