Glucocorticoid "Programming" and PTSD Risk

Maternal, not paternal, PTSD is related to increased risk for PTSD in offspring of Holocaust survivors

BACKGROUND

A significant association between parental PTSD and the occurrence of PTSD in offspring has been noted, consistent with the idea that risk for the development of PTSD is transmitted from parent to child. Two recent reports linking maternal PTSD and low offspring cortisol prompted us to examine the relative contributions of maternal vs. paternal PTSD in the prediction of PTSD and other psychiatric diagnoses in offspring.

METHODS

One hundred seventeen men and 167 women, recruited from the community, were evaluated using a comprehensive psychiatric battery designed to identify traumatic life experiences and lifetime psychiatric diagnoses. 211 of these subjects were the adult offspring of Holocaust survivors and 73 were demographically comparable Jewish controls. Participants were further subdivided based on whether their mother, father, neither, or both parents met diagnostic criteria for lifetime PTSD.

RESULTS

A higher prevalence of lifetime PTSD, mood, anxiety disorders, and to a lesser extent, substance abuse disorders, was observed in offspring of Holocaust survivors than controls. The presence of maternal PTSD was specifically associated with PTSD in adult offspring of Holocaust survivors. However, other psychiatric diagnoses did not show specific effects associated with maternal PTSD.

CONCLUSION

The tendency for maternal PTSD to make a greater contribution than paternal PTSD to PTSD risk suggests that classic genetic mechanisms are not the sole model of transmission, and paves way for the speculation that epigenetic factors may be involved. In contrast, PTSD in any parent contributes to risk for depression, and parental traumatization is associated with increased anxiety disorders in offspring.

Behavioral stress is affected by the mode of tube feeding in very low birth weight infants

OBJECTIVE

To compare the effect of continuous versus bolus feeding on behavioral responses of stress in very low birth weight infants during early postnatal life.

METHODS

In a randomized, controlled trial conducted at 3 neonatal units, 70 premature infants with gestational age 24 to 29 weeks and birth weight <1200 g were randomly assigned to 1 of 3 feeding methods: continuous nasogastric feeding, bolus nasogastric feeding, and bolus orogastric feeding. Behavioral responses were video recorded during feeding at 7 and 15 days of postnatal age and at 32 weeks of postmenstrual age. The odds ratio (OR) of manifest behavioral stress was calculated by means of logistic regression.

RESULTS

A significantly higher risk of a behavioral stress response in bolus-fed infants compared with continuous-fed infants at 15 days of age was observed, [adjusted OR=4.1 (95% confidence interval: 1.1-15.4)]. A similar difference was observed at 32 weeks of postmenstrual age [adjusted OR=4.2 (95% confidence interval: 1.0-17.8)]. In addition, bolus-fed infants showed statistically significant higher need of behavioral and physiologic stabilization during feeding.

DISCUSSION

This trial suggests that continuous feeding is associated with lower behavioral stress response as compared with bolus feeding among very low birth weight infants, in early postnatal life.

Prenatal stress and risk for autism

This paper reviews several converging lines of research that suggest that prenatal exposure to environmental stress may increase risk for Autistic Disorder (AD). We first discuss studies finding that prenatal exposure to stressful life events is associated with significantly increased risk of AD, as well as other disorders, such as schizophrenia and depression. We then review evidence from animal and human studies that prenatal stress can produce both (a) abnormal postnatal behaviors that resemble the defining symptoms of AD, and (b) other abnormalities that have elevated rates in AD, such as learning deficits, seizure disorders, perinatal complications, immunologic and neuroinflammatory anomalies, and low postnatal tolerance for stress. We explain why an etiologic role for prenatal stress is compatible with genetic factors in AD, and describe how stress can disrupt fetal brain development. Finally, we discuss implications for understanding underlying processes in AD, including potential gene-environment interactions, and developing new therapies and early prevention programs.

Interaction with stressed mothers affects corticosterone levels in pups after reunion and impairs the response to dexamethasone in adult mice

BACKGROUND

Early adverse experiences are preeminent factors for the development of affective disorders. In the present study, we analyzed the effects of different postnatal manipulations applied either on the mother or on the offspring in mice. Maternal behavior and adrenocortical activity of both mothers and offspring at the end of postnatal stress and at adulthood were considered.

METHODS

From postnatal day (PND) 1 to 14 mice underwent 15min of: (a) brief (15min) pups' exposure to clean bedding (CB: clean bedding), (b) mothers' exposure to the odor of a novel male (SM: stressed mother) or (c) mothers' exposure to a clean cage (CSM: control stressed mother), and (d) standard rearing (N-H: non-handled). The behavior of mouse dams during and after stress sessions was analyzed. Serum corticosterone of mothers and pups at the end of the stress session and 30min after reunion was assessed on PND 14. Moreover, anxiety levels and HPA-axis inhibitory feedback in response to dexamethasone administration were evaluated in adult male offspring.

RESULTS

Overall, during the 14 days of treatment CB mothers when reunited with their pups showed higher maternal behavior than other dams. After the last stress (PND 14) SM and CSM maternal corticosterone levels increased as well as those of CB pups. While 30min of mother-infant interaction restored baseline corticosterone levels in SM and CSM mothers and in CB pups, SM and CSM offspring showed a decrease of corticosterone under baseline levels. At adulthood, SM and CSM males did not show the suppressive hormonal response to dexamethasone treatment. Moreover, adult CB and SM male mice displayed decreased anxiety in the open field.

CONCLUSIONS

Maternal psychosocial stress during lactation seems to permanently affect the offspring's HPA functioning. These effects may be dissociated from the behavioral response as suggested by the decrease of anxiety in SM and CB adult mice.

Maternal antenatal anxiety and amniotic fluid cortisol and testosterone: possible implications for foetal programming

Both animal and human studies have shown that maternal stress or anxiety during pregnancy is associated with increased risk of disturbance in offspring neurodevelopment and behaviour. In animal models, increased foetal exposure to glucocorticoids has been found to be one mechanism for such foetal programming. Little is understood of the mediating mechanisms in humans, and one aim of our research programme is to investigate this further. This review presents a synopsis of some of our recent results. We aimed to test the hypothesis that maternal anxiety was associated with raised maternal cortisol, and that this in turn was related to increased foetal exposure to cortisol. We studied this by recruiting women at amniocentesis, obtained their Spielberger State Anxiety scores, and assessed maternal plasma cortisol and amniotic fluid cortisol. We also examined maternal plasma and amniotic fluid testosterone levels. Awaiting amniocentesis was in general anxiogenic, but with a wide range of anxiety scores. Maternal anxiety was significantly associated with plasma cortisol before 17 weeks, albeit of modest magnitude (r = 0.0.23), and not after 17 weeks of gestation. This is probably due to the known attenuation of the maternal hypothalamic-pituitary-adrenal axis with increasing gestation. We found a strong correlation between maternal plasma and amniotic fluid cortisol levels, which increased with gestation and became robust after 18 weeks. This correlation increased with maternal anxiety, suggesting a possible effect of maternal mood on placental function. There was a positive correlation between cortisol and testosterone in amniotic fluid, in both male and female foetuses independent of maternal anxiety, plasma testosterone, gestational age, and time of collection. Foetal stress may be associated with increased foetal exposure to testosterone. However, maternal anxiety did not predict amniotic fluid cortisol or testosterone level. Thus, the role of these hormones in mediating the effect of maternal mood on foetal development in humans remains to be demonstrated.

CNS effects of developmental Pb exposure are enhanced by combined maternal and offspring stress

Lead (Pb) exposure and elevated stress are co-occurring risk factors. Both impact brain mesolimbic dopamine/glutamate systems involved in cognitive functions. We previously found that maternal stress can potentiate Pb-related adverse effects in offspring at blood Pb levels averaging approximately 40 microg/dl. The current study of combined Pb exposure and stress sought to extend those results to lower levels of Pb exposure, and to examine relationships among consequences in offspring for fixed interval (FI) schedule-controlled behavior, neurochemistry and corticosterone levels. Dams were exposed to maternal Pb beginning 2 months prior to breeding (0, 50 or 150 ppm in drinking water), maternal restraint stress on gestational days 16 and 17 (MS), or the combination. In addition, a subset of offspring from each resultant treatment group was also exposed intermittently to variable stressors as adults (MS+OS). Marked "Pb-stress"-related increases in response rates on a fixed interval schedule, a behavioral performance with demonstrated sensitivity to Pb, occurred preferentially in female offspring even at mean blood Pb levels of 11 microg/dl when 50 ppm Pb was combined with maternal and offspring stress. Greater sensitivity of females to frontal cortex catecholamine changes may contribute to the elevated FI response rates as mesocorticolimbic systems are critical to the mediation of this behavior. Basal and final corticosterone levels of offspring used to evaluate FI performance differed significantly from those of non-behaviorally tested (NFI) littermates, demonstrating that purported mechanisms of Pb, stress or Pb/stress effects determined in non-behaviorally trained animals cannot necessarily be generalized to animals with behavioral histories. Finally, the persistent and permanent consequences of Pb, stress and Pb+stress in offspring of both genders suggest that Pb screening programs should include pregnant women at risk for elevated Pb exposure, and that stress should be considered as an additional risk factor. Pb+stress effects observed in the absence of either risk factor alone (i.e., potentiated effects) raise questions about the capacity of current hazard identification approaches to adequately identify human health risks posed by neurotoxicants.

Prenatal stress enhances responsiveness to cocaine

Early environmental events have profound influences on a wide range of adult behavior. In the current study, we assessed the influence of maternal stress during gestation on psychostimulant and neurochemical responsiveness to cocaine, cocaine self-administration, and reinstatement of cocaine-seeking in adult offspring. Pregnant, female Sprague-Dawley rats were subjected to either no treatment or to restraint stress three times per day for the last 7 days of gestation and cocaine-related behavior was assessed in offspring at 10 weeks of age. Relative to controls, a noncontingent cocaine injection elevated locomotor activity as well as nucleus accumbens levels of extracellular dopamine and glutamate to a greater extent in both cocaine-naive and cocaine-experienced prenatal stress (PNS) rats and elevated prefrontal cortex dopamine in cocaine-experienced PNS rats. To assess the impact of PNS on cocaine addiction-related behavior, rats were trained to lever press for intravenous (i.v.) infusions of cocaine (0.25, 0.5, or 1 mg/kg/infusion), with each infusion paired with a light+tone-conditioned stimulus. Lever-pressing was extinguished and cocaine-seeking reinstated by re-exposure to the conditioned cues or by intraperitoneal cocaine-priming injections (5 or 10 mg/kg). PNS elevated active lever responding both during extinction and cocaine-primed reinstatement, but not during self-administration or conditioned-cued reinstatement. PNS also did not alter intake during self-administration. These findings demonstrate that PNS produces enduring nervous system alterations that increase the psychomotor stimulant, motivational, and neurochemical responsiveness to noncontingent cocaine. Thus, early environmental factors contribute to an individual's initial responsiveness to cocaine and propensity to relapse to cocaine-seeking.

The influence of stress hormones on emotional memory: relevance for psychopathology

Substantial progress within recent years has led to a better understanding of the impact of stress on emotional memory. These effects are of relevance for understanding and treating psychopathology. The present selective review describes how emotional memory is modulated through stress hormones. Acute as well as chronic effects are discussed and information from rodent models is compared to human experimental studies and clinical observations. Finally, the relevance of these findings for emotional memory disturbances in psychiatric disorders is exemplified by discussions on neuroendocrine alterations in depression, post traumatic stress disorder and phobias.

Social bonds and posttraumatic stress disorder

Retrospective and prospective studies consistently show that individuals exposed to human-generated traumatic events carry a higher risk of developing Posttraumatic Stress Disorder (PTSD) than those exposed to other kinds of events. These studies also consistently identify perceptions of social support both before and after a traumatic event as an important factor in the determining vulnerability to the development of PTSD. We review the literature on interpersonal traumas, social support and risk for PTSD and integrate findings with recent advances in developmental psychopathology, attachment theory and social neuroscience. We propose and gather evidence for what we term the social ecology of PTSD, a conceptual framework for understanding how both PTSD risk and recovery are highly dependent on social phenomena. We explore clinical implications of this conceptual framework.

Outcomes at 2 years of age after repeat doses of antenatal corticosteroids

BACKGROUND

We previously reported the results of a randomized, controlled trial showing that repeat doses of antenatal corticosteroids reduced the risk of respiratory distress syndrome and serious neonatal morbidity. However, data have not been available regarding longer-term effects of this treatment.

METHODS

Women who had received an initial course of corticosteroid treatment 7 or more days previously were randomly assigned to receive an intramuscular injection of corticosteroid (11.4 mg of betamethasone) or saline placebo; the dose was repeated weekly if the mother was still considered to be at risk for preterm delivery and the duration of gestation was less than 32 weeks. We assessed survival free of major neurosensory disability and body size of the children at 2 years of corrected age.

RESULTS

Of the 1085 children who were alive at 2 years of age, 1047 (96.5%) were seen for assessment (521 exposed to repeat-corticosteroid treatment and 526 exposed to placebo). The rate of survival free of major disability was similar in the repeat-corticosteroid and placebo groups (84.4% and 81.0%, respectively; adjusted relative risk, 1.04, 95% confidence interval, 0.98 to 1.10; adjusted P=0.20). There were no significant differences between the groups in body size, blood pressure, use of health services, respiratory morbidity, or child behavior scores, although children exposed to repeat doses of corticosteroids were more likely than those exposed to placebo to warrant assessment for attention problems (P=0.04).

CONCLUSIONS

Administration of repeat doses of antenatal corticosteroids reduces neonatal morbidity without changing either survival free of major neurosensory disability or body size at 2 years of age. (Current Controlled Trials number, ISRCTN48656428 [controlled-trials.com].).

Cord blood cortisol level is lower in growth-restricted newborns

AIM

To establish the difference in plasma cortisol concentrations between newborns with intrauterine growth-restricted (IUGR) and appropriate for gestational age (AGA) birthweights.

SUBJECTS AND METHODS

We measured plasma cortisol concentrations in the umbilical venous cord blood of 68 IUGR newborns and 71 AGA birthweight newborns. All newborns were delivered in term, vaginally, in the morning, within 8 hours and had APGAR scores greater or equal to eight.

RESULTS

There was no significant difference between compared groups according to maternal age, parity, gestational age and neonatal gender. Neonatal plasma cortisol levels were significantly lower in the IUGR (median: 312.3 mmol/L, min-max: 158.9-588.1 mmol/L) compared to the AGA group (median: 458.7 mmol/L, min-max: 314.5-718.5 mmol/L) (Mann-Whitney U-test; P<0000). The probability of having a cortisol plasma level greater than or equal to 458.7 mmol/L for IUGR newborns was only 1:12, and to have cortisol plasma level less than or equal to 312.3 mmol/L for AGA newborns was much lower (0:34). In the range of plasma cortisol level between 312.3 mmol/L and 458.7 mmol/L, no statistically significant difference in the plasma cortisol level between IUGR and AGA newborns was found.

CONCLUSIONS

Neonatal plasma cortisol level is lower in the IUGR compared to the AGA group. Our results suggest that endocrine relationships seem to be lost in a specific group of the IUGR newborns. Although we usually tend to simplify the problem and declare only one cause, this time it is impossible. It is probable that the cause is hidden in small and insufficient placenta with deranged auto-regulation of placental 11beta-HSD-2 mechanism.

Role of the placenta in fetal programming: underlying mechanisms and potential interventional approaches

Adverse influences during fetal life alter the structure and function of distinct cells, organ systems or homoeostatic pathways, thereby ‘programming’ the individual for an increased risk of developing cardiovascular disease and diabetes in adult life. Fetal programming can be caused by a number of different perturbations in the maternal compartment, such as altered maternal nutrition and reduced utero–placental blood flow; however, the underlying mechanisms remain to be fully established. Perturbations in the maternal environment must be transmitted across the placenta in order to affect the fetus. Here, we review recent insights into how the placenta responds to changes in the maternal environment and discuss possible mechanisms by which the placenta mediates fetal programming. In IUGR (intrauterine growth restriction) pregnancies, the increased placental vascular resistance subjects the fetal heart to increased work load, representing a possible direct link between altered placental structure and fetal programming of cardiovascular disease. A decreased activity of placental 11β-HSD-2 (type 2 isoform of 11β-hydroxysteroid dehydrogenase) activity can increase fetal exposure to maternal cortisol, which programmes the fetus for later hypertension and metabolic disease. The placenta appears to function as a nutrient sensor regulating nutrient transport according to the ability of the maternal supply line to deliver nutrients. By directly regulating fetal nutrient supply and fetal growth, the placenta plays a central role in fetal programming. Furthermore, perturbations in the maternal compartment may affect the methylation status of placental genes and increase placental oxidative/nitrative stress, resulting in changes in placental function. Intervention strategies targeting the placenta in order to prevent or alleviate altered fetal growth and/or fetal programming include altering placental growth and nutrient transport by maternally administered IGFs (insulin-like growth factors) and altering maternal levels of methyl donors.

How can drug discovery for psychiatric disorders be improved?

Psychiatric disorders such as depression, anxiety and schizophrenia are leading causes of disability worldwide, and have a huge societal impact. However, despite the clear need for better therapies, and major advances in the understanding of the molecular basis of these disorders in recent years, efforts to discover and develop new drugs for neuropsychiatric disorders, particularly those that might revolutionize disease treatment, have been relatively unsuccessful. A multidisciplinary approach will be crucial in addressing this problem, and in the first Advances in Neuroscience for Medical Innovation symposium, experts in multiple areas of neuroscience considered key questions in the field, in particular those related to the importance of neuronal plasticity. The discussions were used as a basis to propose steps that can be taken to improve the effectiveness of drug discovery for psychiatric disorders.

The genetic background to PTSD

Although extensive research has already been done on the genetic bases of psychiatric disorders, little is known about polygenetic influences in posttraumatic stress disorder (PTSD). This article reviews molecular genetic studies relating to PTSD that were found in a literature search in Medline, Embase and Web of Science. Association studies have investigated 8 major genotypes in connection with PTSD. They have tested hypotheses involving key candidate genes in the serotonin (5-HTT), dopamine (DRD2, DAT), glucocorticoid (GR), GABA (GABRB), apolipoprotein systems (APOE2), brain-derived neurotrophic factor (BDNF) and neuropeptide Y (NPY). The studies have produced inconsistent results, many of which may be attributable to methodological shortcomings and insufficient statistical power. The complex aetiology of PTSD, for which experiencing a traumatic event forms a necessary condition, makes it difficult to identify specific genes that substantially contribute to the disorder. Gene-finding strategies are difficult to apply. Interactions between different genes and between them and the environment probably make certain people vulnerable to developing PTSD. Gene-environmental studies are needed that focus more narrowly on specific, distinct endophenotypes and on influences from environmental factors.