Neuroendocrine aspects of pediatric aggression: Can hormone measures be clinically useful?

A machine learning approach for understanding the metabolomics response of children with autism spectrum disorder to medical cannabis treatment

Autism spectrum disorder (ASD) is a neurodevelopmental condition impacting behavior, communication, social interaction and learning abilities. Medical cannabis (MC) treatment can reduce clinical symptoms in individuals with ASD. Cannabis-responsive biomarkers are metabolites found in saliva that change in response to MC treatment. Previously we showed levels of these biomarkers in children with ASD successfully treated with MC shift towards the physiological levels detected in typically developing (TD) children, and potentially can quantify the impact. Here, we tested for the first time the capabilities of machine learning techniques applied to our dynamic, high-resolution and rich feature dataset of cannabis-responsive biomarkers from a limited number of children with ASD before and after MC treatment and a TD group to identify: (1) biomarkers distinguishing ASD and TD groups; (2) non-cannabinoid plant molecules with synergistic effects; and (3) biomarkers associated with specific cannabinoids. We found: (1) lysophosphatidylethanolamine can distinguish between ASD and TD groups; (2) novel phytochemicals contribute to the therapeutic effects of MC treatment by inhibition of acetylcholinesterase; and (3) THC- and CBD-associated cannabis-responsive biomarkers are two distinct groups, while CBG is associated with some biomarkers from both groups.

Psychobiological Correlates of Aggression in Female Adolescents with Borderline Personality Disorder

INTRODUCTION

Aggressive behavior in reaction to threats, frustration, or provocation is prevalent in borderline personality disorder (BPD). This study investigated aggressive behavior and its biological correlates in adolescents with BPD.

METHODS

Twenty-one female adolescents with a DSM-IV BPD diagnosis and 25 sex- and age-matched healthy controls participated in the Taylor Aggression Paradigm (TAP), a laboratory-based experiment measuring aggressive behavior in the interpersonal context. Heart rate was measured and saliva samples were taken throughout the experiment.

RESULTS

Multilevel mixed-effects linear regression analyses revealed no significant group difference in aggressive behavior induced by the TAP. Additionally, the two groups did not differ in cortisol, testosterone, and heart rate responses to the aggression induction. The BPD group showed a significant cortisol increase in the time preceding the start of the TAP in contrast to the healthy control group, in whom a significant heart rate increase from baseline to the first block of the TAP was observed.

DISCUSSION

There was no evidence, either at the phenomenological or the biological level, of increased task-induced aggression in adolescents with BPD. The results may indicate that adolescents with BPD experienced fearful stress in anticipation of the experimental task in contrast to healthy controls who showed an adaptive response of the autonomic nervous system necessary to deal with the upcoming demand.

An Exploratory Cohort Study of the Association between the Level of Testosterone and Suicidal Ideation in Hospitalized Adolescent Females with Depression in China

BACKGROUND

To date, around 4 per 100,000 adolescents committed suicide within the 29 OECD countries. The suicidal behavior is related to psychological factors, genetics, neurobiology, and other biomarkers. The aim of this study was to examine risk factors for the development of suicidal ideation in adolescent females with depression, focusing on the relationship between different testosterone levels and suicidal ideation, in order to help develop strategies to intervene in suicidal behavior in female adolescents with depression.

METHOD

In this single-center prospective cohort study, we enrolled adolescent females with depression. We collected information on their baseline data, testosterone levels, symptom self-rating scale scores, suicidal ideation, non-suicidal self-injurious (NSSI) behaviours, and suicide attempts. We used multivariate logistic regression to identify risk factors for the development of suicidal ideation in adolescent females with depression.

RESULTS

A total of 113 hospitalized adolescent females were enrolled with a mean age of 13.5 (1.20). Among these patients, there were 86 (76.11%) subjects who suffered from suicidal ideation, 59 (52.21%) had NSSI and 23 (20.35%) had suicide attempt behavior. In the final model, higher level of testosterone (p=0.04) and higher age (p=0.02) were associated with the higher odds of having suicidal ideation.

CONCLUSION

In this exploratory cohort study, the emergence of suicidal ideation was common among adolescent females with depression. This study is consistent with the other studies. It shows that the age is a potential predictor for suicidal ideation in hospitalized adolescent females with depression.

Association of Corticotropin-Releasing Hormone Receptor-1 Gene Polymorphisms and Personality Traits with Violent Aggression in Male Adolescents

There is evidence that corticotropin-releasing hormone receptor 1 (CRHR1) gene polymorphisms and indifferent impulsive personality traits play an important role in violent aggression in male adolescents. Genotyping for two tag single-nucleotide polymorphisms (SNP) (rs242924, rs17689966) was conducted using TaqMan SNP for 138 violent young male criminals, 98 nonviolent young male criminals, and 153 noncriminal adults. The general situation and personality traits (SSP) questionnaire was given to the young violent and nonviolent male criminal groups. The results showed that the frequency of the G allele in rs242924 of the CRHR1 gene in the violent aggression group was higher than that in the normal adult controls (P < 0.025, OR = 2.29, 95% CI = 1.13-4.62). The difference in genotype distribution was significant among the three groups (P < 0.05), and when the violent group was compared with the two control groups, no significant difference was found (P > 0.025). The impulsiveness, trait irritability, verbal trait aggression, and physical trait aggression scores in the violent group were significantly higher than those in the nonviolent group of adolescents. These findings suggest that the variance in CRHR1 gene polymorphisms and personality traits may play a role in violent aggression in male adolescents, and that the interaction of the CRHR1 gene and the impulsive personality trait may cause an increased susceptibility to violence towards others.

Highly aggressive behavior induced by social stress is associated to reduced cytochrome c oxidase activity in mice brain cortex

Violence and aggression represent severe social problems, with profound impacts on public health. Despite the development of experimental models to study aggressive behavior is highly appreciated, the underlying mechanisms remain poorly understood. Given the key contribution of mitochondria to central nervous system bioenergetics, we hypothesized that mitochondrial function in brain would be altered by social stress. Using a model of spontaneous aggression, we investigated here the effects of social stress on brain mitochondrial function in prefrontal cortex of Swiss mice. Animals were categorized as highly aggressive, subordinate and non-aggressive (harmonic) after stress induced by regrouping and compared them with non-regrouped animals. Despite social stress did not affect brain cortex oxygen consumption rates and NADH:cytochrome c oxidoreductase activity, cytochrome c oxidase expression and activity were significantly lower in highly aggressive animals compared to non-regrouped ones. These changes were not observed in ATP synthase and adenine nucleotide translocator content suggesting a selective effect of social stress on cytochrome c oxidase. Therefore, aggressive behavior generated upon social stress associates to selective reduction in cytochrome c oxidase activity, with potential detrimental effects on brain bioenergetics and function.

The role of trauma in the hormonal interplay of cortisol, testosterone, and oxytocin in adolescent aggression

Although numerous studies have examined the neuroendocrinology of aggression, the findings are mixed and focused on cortisol and testosterone. We argue that past findings remain inconclusive partly because the key roles of oxytocin and trauma have not been systematically integrated yet. Oxytocin is associated with social behavior and interacts with cortisol and testosterone, whereas trauma is a crucial risk factor of aggression that strongly affects hormonal activity. In this review, we investigate the role of trauma in the hormonal interplay of cortisol, testosterone, and oxytocin in aggression during adolescence. We first discuss how these hormones interact with each other and how trauma influences these interactions and then we propose a model that highlights the role of trauma in the hormonal interplay in aggression. We suggest that the timing of trauma has a distinct effect on hormonal activity and it should be integrated into any comprehensive model. Current trauma is linked to different levels of oxytocin, cortisol, testosterone, and testosterone/cortisol ratio than childhood trauma, but this distinction is also influenced by gender and type of aggression. We conclude that in order to better understand the neuroendocrinology of aggression, it is crucial to incorporate the investigation of oxytocin and trauma in future research.

Effects of adrenal androgens during the prenatal period on the second to fourth digit ratio in school-aged children

OBJECTIVES

We investigated the relationship between the levels of adrenal steroid hormones in cord blood and the second to fourth digit ratio (2D/4D), which is regarded as an indirect method to investigate the putative effects of prenatal exposure to androgens, in school-aged children.

MATERIALS AND METHODS

Of the 514 mother-child pairs who participated in the prospective cohort study of birth in Sapporo between 2002 and 2005, the following adrenal steroid hormone levels in 294 stored cord blood samples (135 males and 159 females) were measured; cortisol, cortisone, androstenedione and dehydroepiandrosterone (DHEA). A total of 190 out of 350 children who were currently school-aged and contactable for this survey sent back photocopies of their palms for 2D/4D measurements.

RESULTS

2D/4D in all right hands, left hands, and mean values was significantly lower in males than in females (p<0.01). DHEA levels were significantly higher in females. A multivariate regression model showed that 2D/4D negatively correlated with DHEA in males only (p<0.01). No correlations were observed in the other adrenal steroid hormones tested in males or in any adrenal steroid hormones in females.

CONCLUSION

DHEA is mainly secreted in large amounts by the adrenal gland and is transformed into active sex-steroid hormones in peripheral tissues. The present study demonstrated that sex differences in digits were influenced by adrenal androgens during the prenatal period, possibly through intracrinological processes for androgen receptors located in fetal cartilaginous tissues.

Discovery of biochemical biomarkers for aggression: A role for metabolomics in psychiatry

Human aggression encompasses a wide range of behaviors and is related to many psychiatric disorders. We introduce the different classification systems of aggression and related disorders as a basis for discussing biochemical biomarkers and then present an overview of studies in humans (published between 1990 and 2015) that reported statistically significant associations of biochemical biomarkers with aggression, DSM-IV disorders involving aggression, and their subtypes. The markers are of different types, including inflammation markers, neurotransmitters, lipoproteins, and hormones from various classes. Most studies focused on only a limited portfolio of biomarkers, frequently a specific class only. When integrating the data, it is clear that compounds from several biological pathways have been found to be associated with aggressive behavior, indicating complexity and the need for a broad approach. In the second part of the paper, using examples from the aggression literature and psychiatric metabolomics studies, we argue that a better understanding of aggression would benefit from a more holistic approach such as provided by metabolomics. © 2016 Wiley Periodicals, Inc.

DHEA effects on brain and behavior: insights from comparative studies of aggression

Historically, research on the neuroendocrinology of aggression has been dominated by the paradigm that the brain receives sex steroid hormones, such as testosterone (T), from the gonads, and then these gonadal hormones modulate behaviorally relevant neural circuits. While this paradigm has been extremely useful for advancing the field, recent studies reveal important alternatives. For example, most vertebrate species are seasonal breeders, and many species show aggression outside of the breeding season, when the gonads are regressed and circulating levels of gonadal steroids are relatively low. Studies in diverse avian and mammalian species suggest that adrenal dehydroepiandrosterone (DHEA), an androgen precursor and prohormone, is important for the expression of aggression when gonadal T synthesis is low. Circulating DHEA can be converted into active sex steroids within the brain. In addition, the brain can synthesize sex steroids de novo from cholesterol, thereby uncoupling brain steroid levels from circulating steroid levels. These alternative mechanisms to provide sex steroids to specific neural circuits may have evolved to avoid the costs of high circulating T levels during the non-breeding season. Physiological indicators of season (e.g., melatonin) may allow animals to switch from one neuroendocrine mechanism to another across the year. DHEA and neurosteroids are likely to be important for the control of multiple behaviors in many species, including humans. These studies yield fundamental insights into the regulation of DHEA secretion, the mechanisms by which DHEA affects behavior, and the brain regions and neural processes that are modulated by DHEA. It is clear that the brain is an important site of DHEA synthesis and action. This article is part of a Special Issue entitled 'Essential role of DHEA'.

Increased severity of suicidal behavior in impulsive aggressive patients exposed to familial adversities

BACKGROUND

The mechanisms by which childhood abuse and family history of suicidal behavior (FHS) lead to an increased risk of suicidal behavior are still unknown. Impulsive aggression may play an intermediate role. We investigated whether greater scores for aggression and impulsivity might be associated with the effects of FHS and/or childhood abuse on the severity of suicidal behavior.

METHOD

We examined the scores of three scales measuring impulsive aggression in a sample of 696 suicide attempters. We compared the highest and lowest scores with regard to reports of childhood abuse and FHS using adjusted multinomial regression models. Genetic polymorphisms of the serotonergic system known to be associated with impulsive aggression were also analyzed.

RESULTS

Patients with high impulsive aggressive scores showed significant differences in sociodemographic, clinical and suicidal features compared with patients with low impulsive aggressive scores. Adjusted results showed that combinations of some types of childhood abuse and FHS, particularly emotional abuse and emotional neglect, are associated with high impulsivity and hostility scores. The SS genotype of the serotonin transporter gene (5-HTTLPR) was associated with high levels of impulsivity when the subjects reported emotional abuse [odds ratio (OR) 5.55, 95% confidence interval (CI) 1.75-17.5] or physical abuse (OR 5.03, 95% CI 1.50-16.9) in their childhood.

CONCLUSIONS

Our results support the role of impulsive aggression as one of the links that may connect childhood abuse and FHS with severity of suicidal behavior.

The association between salivary hormone levels and children's inpatient aggression: a pilot study

Aggression is a common management problem for child psychiatry hospital units. We describe an exploratory study with the primary objective of establishing the feasibility of linking salivary concentrations of three hormones (testosterone, dehydroepiandrosterone [DHEA], and cortisol) with aggression. Between May 2011 and November 2011, we recruited 17 psychiatrically hospitalized boys (age 7-9 years). We administered the Brief Rating of Aggression by Children and Adolescents (BRACHA) and Predatory-Affective Aggression Scale (PAAS) upon admission. Saliva samples were collected from the participants during a 24-h period shortly after admission: immediately upon awakening, 30 min later, and again between 3:45 and 7:45 P.M. Nursing staff recorded Overt Aggression Scale ratings twice a day during hospitalization to quantify aggressive behavior. The salivary cortisol concentrations obtained from aggressive boys 30 min after awakening trended higher than levels from the non-aggressive boys (p = 0.06), were correlated with the number of aggressive incidents (p = 0.04), and trended toward correlation with BRACHA scores (p = 0.06). The aggressive boys also showed greater morning-to-evening declines in cortisol levels (p = 0.05). Awakening levels of DHEA and testosterone were correlated with the severity of the nearest aggressive incident (p < 0.05 for both). The BRACHA scores of the aggressive boys were significantly higher than scores of the non-aggressive boys (p < 0.001). Our data demonstrate the feasibility of collecting saliva from children on an inpatient psychiatric unit, affirm the utility of the BRACHA in predicting aggressive behavior, and suggest links between salivary hormones and aggression by children who undergo psychiatric hospitalization.

The cognitive and neural correlates of psychopathy and especially callous–unemotional traits in youths: A systematic review of the evidence

It is unclear whether the concepts and findings of the underlying neurobiology of adult psychopathy apply to youths as well. If so, a life span approach to treatment should be taken. Because youths’ brains are still developing, interventions at an early age may be far more effective in the long run. The aim of this systematic review is to examine whether the neurocognitive and neurobiological factors that underlie juvenile psychopathy, and specifically callous–unemotional (CU) traits, are similar to those underlying adult psychopathy. The results show that youths with CU traits show lower levels of prosocial reasoning, lower emotional responsivity, and decreased harm avoidance. Brain imaging studies in youths with CU traits are still rare. Available studies suggest specific neural correlates, such as a reduced response of the amygdala and a weaker functional connectivity between the amygdala and the ventromedial prefrontal cortex. These findings are largely in line with existing theories of adult psychopathy, such as the dual-hormone serotonergic hypothesis and the integrated emotions systems theory. We recommend that future studies investigate the role of oxytocin, invest in the study of neural mechanisms, and study the precursors, risk factors, and correlates of CU traits in early infancy and in longitudinal designs.