Delivering transgender-specific knowledge and skills into health and allied health studies and training: a systematic review.

Many transgender individuals face inequities, discrimination, and sometimes even a lack of transgender-specific knowledge in health care settings. Educational curricula can address such disparities and help future health professionals to become more knowledgeable, confident, and well-prepared for addressing the needs of transgender individuals. This systematic review aims to summarize current training interventions about care of transgender individuals for health and allied health students, and to analyse the effects of the respective intervention. A total of six databases (Pubmed, MEDLINE, Scopus, Web of Science, Embase and SciSearch) were screened for original articles published between 2017 and June 2021. Search terms and eligibility criteria were pre-specified, and after a structured selection process 21 studies were included into further analysis. Extracted data contained information on general study properties, population, design, program format and outcomes of interest. A narrative synthesis was used to summarize detected results. Study quality was assessed for each individual study. A self-developed 18-item checklist combining criteria of two prior published tools was used to assess overall quality of quantitative studies. For qualitative studies a 10-item checklist by Kmet et al. [HTA Initiat, 2004] was applied. Eligible studies were designed for multiple health or allied health profession students, and varied widely regarding program format, duration, content, and assessed outcomes. Almost all (N = 19) interventions indicated improvements in knowledge, attitude, confidence and comfort levels or practical skills concerning care for transgender clients. Major limitations included the lack of long-term data, validated assessment tools, control groups and comparative studies. Training interventions contribute to prepare future health professionals to deliver competent and sensitive care and which may improve the prospective experienced health care reality of transgender individuals. However, currently there is no common consensus about best practice of education. Additionally, little is known about whether detected effects of training interventions translate into noticeable improvements for transgender clients. Further studies are warranted to assess the direct impact of specific interventions in the light of the respective target populations.

Child and adolescent psychiatry training in Australia and New Zealand.

The specialty of Child and Adolescent Psychiatry was formally recognised in the 1930s. The Faculty of Child and Adolescent Psychiatry was established in 1964 in Australia, as a subspecialty in The Royal Australian and New Zealand College of Psychiatrists (RANZCP). The aim of the current article is first to provide a brief summary and overview of the current status of Child and Adolescent Psychiatry (CAP), followed by an outline of the requirements of the Training Program for CAP in Australia and New Zealand. The training required to become a fully qualified child and adolescent psychiatrist in Australia and New Zealand consists of different stages and takes the form of competency-based training. Information relating to assessment types, supervision and research requirements is also described. Accreditation procedures for the training program are stipulated by RANZCP to monitor standards and to ensure consistency within the programs delivered across Australia and New Zealand. Employment opportunities for trainees upon completion of the program are discussed. In summary, this article highlights the requirements of the training programs for CAP in Australia and New Zealand.

Effects of serotonin depletion and dopamine depletion on bimodal divided attention.

Objectives: This study aimed to explore the effects of acute phenylalanine tyrosine depletion (APTD) and acute tryptophan depletion (ATD) on bimodal divided attention. A balanced amino acid mixture (BAL) served as control condition.Methods: Fifty-three healthy adults (final analyzed sample was N = 49, age: M = 23.8 years) were randomly assigned to APTD, ATD or BAL in a double-blind, between-subject approach. Divided attention was assessed after 4 h. Blood samples were taken before and 6 h after challenge intake.Results: Amino acid concentrations following challenge intake significantly decreased (all P ≤ 0.01). There was a significant difference in the mean reaction time (RT) towards auditory stimuli, but not towards visual stimuli between the groups. Post-hoc comparison of mean RTs (auditory stimuli) showed a significant difference between ATD (RT = 604.0 ms, SD = 56.9 ms) and APTD (RT = 556.4 ms, SD = 54.2 ms; P = 0.037), but no RT difference between ATD and BAL or APTD and BAL (RT = 573.6 ms, SD = 45.7 ms).Conclusions: The results indicate a possible dissociation between the effects of a diminished brain 5-HT and DA synthesis on the performance in a bimodal divided attention task. The difference was exclusively observed within the RT towards auditory signals.

Serotonin and aggressive behaviour in children and adolescents: a systematic review.

OBJECTIVE: The role of serotonin (5-HT) in human aggression has been the subject of a large number of studies, mostly with adults. Meta-analyses indicate a small but significant inverse relationship between central nervous 5-HT availability and aggression, but genetically informed studies suggest two pathways: one to reactive aggression and the other to proactive aggression. METHOD: We conducted a systemic review on central nervous 5-HT function in children and adolescents, with attention to the function of aggression. RESULTS: In total, 675 articles were screened for relevance, with 45 reviewed. These included blood assays (e.g. plasma, 5-HIAA; platelet 5-HTR2A ), epigenetic studies, retrospective PET studies and 5-HT challenge paradigms (e.g. tryptophan depletion). Overall, findings were mixed, with support both for negative and for positive associations of central nervous 5-HT function with aggression in children and adolescents. CONCLUSION: We propose factors that may be blurring the picture, including problems in the conceptualization and measurement of aggression in young people, the lack of prospective designs and the bias towards clinical samples of boys. Research needs to account for variance in the both motivation for and implementation of aggression, and look to the behavioural economics literature to consider the roles of reward, vengeance and self-control more clearly.

Resting state default mode network connectivity in children and adolescents with ADHD after acute tryptophan depletion.

OBJECTIVE: Alterations of the default mode network (DMN) have been described in patients with neuropsychiatric disorders, including attention deficit hyperactivity disorder (ADHD), and the neurotransmitter serotonin (5-HT) is known to modulate DMN activity. This study aimed to explore the role of 5-HT on the DMN and its functional connectivity (FC) in young patients with ADHD. METHODS: Young male patients with ADHD (n = 12) and healthy controls (n = 10) (both aged 12-17 years) were subjected to acute tryptophan depletion (ATD) and subsequently diminished brain 5-HT synthesis. Three hours after challenge intake (ATD or a balanced control condition, BAL), resting state fMRI scans were obtained. RESULTS: In patients, ATD led to attenuated FC of the right superior premotor cortex (BA 6) with the DMN, comparable to the extent found in controls after BAL administration. ATD lowered FC of the left somatosensory cortex (BA 3) with the DMN, independently of the factor group, but with stronger effects in controls. CONCLUSIONS: Data reveal a serotonergic modulation of FC between BA 6 and 3, known to be relevant for motor planning and sensory perception, and the DMN, thereby possibly pointing toward ATD acting beneficially on neural planning of motor activity in patients with ADHD.

Serotonergic modulation of resting state default mode network connectivity in healthy women.

The default mode network (DMN) plays a central role in intrinsic thought processes. Altered DMN connectivity has been linked to diminished cerebral serotonin synthesis. Diminished brain serotonin synthesis is further associated with a lack of impulse control and various psychiatric disorders. Here, we investigated the serotonergic modulation of intrinsic functional connectivity (FC) within the DMN in healthy adult females, controlling for the menstrual cycle phase. Eighteen healthy women in the follicular phase (aged 20-31 years) participated in a double-blind controlled cross-over study of serotonin depletion. Acute tryptophan depletion (ATD) and a balanced amino acid load (BAL), used as the control condition, were applied on two separate days of assessment. Neural resting state data using functional magnetic resonance imaging (fMRI) and individual trait impulsivity scores were obtained. ATD compared with BAL significantly reduced FC with the DMN in the precuneus (associated with self-referential thinking) and enhanced FC with the DMN in the frontal cortex (associated with cognitive reasoning). Connectivity differences with the DMN between BAL and ATD in the precentral gyrus were significantly correlated with the magnitude of serotonin depletion. Right medial frontal gyrus and left superior frontal gyrus connectivity differences with the DMN were inversely correlated with trait impulsivity. These findings partially deviate from previous findings obtained in males and underline the importance of gender-specific studies and controlling for menstrual cycle to further elucidate the mechanism of ATD-induced changes within intrinsic thought processes.

Human breast milk and adipokines--A potential role for the soluble leptin receptor (sOb-R) in the regulation of infant energy intake and development.

Concentrations of different adipokines in human breast milk are thought to be able to affect energy intake of the infant. Leptin is a hormone synthesized by adipose tissue and the human placenta and favors satiety. The availability of leptin in breast milk is influenced by epithelial cells of the mammary gland that are known to be able to produce leptin, as well as leptin from maternal circulation that is transported to the breast milk, and which can thus in turn reach neonatal blood after absorption. Research so far as mainly focused on leptin concentrations in breast milk. However, evidence suggests that in addition to leptin concentrations levels of the so-called soluble leptin receptor (sOb-R), the main high-affinity binding protein for leptin in humans, are necessary in order to calculate the free leptin index (FLI) and to assess function of the leptin axis. FLI is calculated from the ratio of leptin to the sOb-R, and serves as the main parameter for assessing function of the leptin axis throughout maturation and development. Here we propose that assessing sOb-R levels in addition to leptin concentrations in breast milk could serve as a valuable tool to investigate effects of the leptin axis in breast milk because sOb-R concentrations can impact available leptin levels, and which in turn can have significant implications for infant energy intake and related development.

Neural correlates of reactive aggression in children with attention-deficit/hyperactivity disorder and comorbid disruptive behaviour disorders.

OBJECTIVE: Attention deficit hyperactivity disorder (ADHD) is often linked with impulsive and aggressive behaviour, indexed by high comorbidity rates between ADHD and disruptive behaviour disorders (DBD). The present study aimed to investigate underlying neural activity of reactive aggression in children with ADHD and comorbid DBD using functional neuroimaging techniques (fMRI). METHOD: Eighteen boys with ADHD (age 9-14 years, 10 subjects with comorbid DBD) and 18 healthy controls were administered a modified fMRI-based version of the 'Point Subtraction Aggression Game' to elicit reactive aggressive behaviour. Trials consisted of an 'aggression phase' (punishment for a fictitious opponent) and an 'outcome phase' (presentation of the trial outcome). RESULTS: During the aggression phase, higher aggressive responses of control children were accompanied by higher activation of the ventral anterior cingulate cortex and the temporoparietal junction. Patients displayed inverted results. During the outcome phase, comparison between groups and conditions showed differential activation in the dorsal striatum and bilateral insular when subjects gained points. Losing points was accompanied by differential activation of regions belonging to the insula and the middle temporal sulcus. CONCLUSION: Data support the hypothesis that deficient inhibitory control mechanisms are related to increased impulsive aggressive behaviour in young people with ADHD and comorbid DBD.

The Role of Serotonin (5-HT) in Behavioral Control: Findings from Animal Research and Clinical Implications.

The neurotransmitters serotonin and dopamine both have a critical role in the underlying neurobiology of different behaviors. With focus on the interplay between dopamine and serotonin, it has been proposed that dopamine biases behavior towards habitual responding, and with serotonin offsetting this phenomenon and directing the balance toward more flexible, goal-directed responding. The present focus paper stands in close relationship to the publication by Worbe et al. (2015), which deals with the effects of acute tryptophan depletion, a neurodietary physiological method to decrease central nervous serotonin synthesis in humans for a short period of time, on the balance between hypothetical goal-directed and habitual systems. In that research, acute tryptophan depletion challenge administration and a following short-term reduction in central nervous serotonin synthesis were associated with a shift of behavioral performance towards habitual responding, providing further evidence that central nervous serotonin function modulates the balance between goal-directed and stimulus-response habitual systems of behavioral control. In the present focus paper, we discuss the findings by Worbe and colleagues in light of animal experiments as well as clinical implications and discuss potential future avenues for related research.

Effects of serotonin depletion on punishment processing in the orbitofrontal and anterior cingulate cortices of healthy women.

Diminished synthesis of the neurotransmitter serotonin (5-HT) has been linked to disrupted impulse control in aversive contexts. However, the neural correlates underlying a serotonergic modulation of female impulsivity remain unclear. The present study investigated punishment-induced inhibition in healthy young women. Eighteen healthy female subjects (aged 20-31) participated in a double-blinded, counterbalanced, placebo-controlled, within subjects, repeated measures study. They were assessed on two randomly assigned occasions that were controlled for menstrual cycle phase. In a randomized order, one day, acute tryptophan depletion (ATD) was used to reduce 5-HT synthesis in the brain. On the other day, participants received a tryptophan-balanced amino acid load (BAL) as a control condition. Three hours after administration of ATD/BAL, neural activity was recorded during a modified Go/No-Go task implementing reward or punishment processes using functional magnetic resonance imaging (fMRI). Neural activation during No-Go trials in punishment conditions after BAL versus ATD administration correlated positively with the magnitude of central 5-HT depletion in the ventral and subgenual anterior cingulate cortices (ACC). Furthermore, neural activation in the medial orbitofrontal cortex (mOFC) and the dorsal ACC correlated positively with trait impulsivity. The results indicate reduced neural sensitivity to punishment after short-term depletion of 5-HT in brain areas related to emotion regulation (subgenual ACC) increasing with depletion magnitude and in brain areas related to appraisal and expression of emotions (mOFC and dorsal ACC), increasing with trait impulsivity. This suggests a serotonergic modulation of neural circuits related to emotion regulation, impulsive behavior, and punishment processing in females.

Amino acid challenge and depletion techniques in human functional neuroimaging studies: an overview.

Imbalances of neurotransmitter systems, particularly serotonin (5-HT) and dopamine (DA), are known to play an essential role in many neuropsychiatric disorders. The transient manipulation of such systems through the alteration of their amino acid precursors is a well-known research tool. Among these methods are alterations of tryptophan, the essential amino acid (AA) precursor of 5-HT, as well as manipulations of tyrosine and phenylalanine, the AA precursors of DA, which can be metabolized into norepinephrine and subsequently into epinephrine. These systems can be loaded by applying a large dose of these AAs or depleted by applying an amino acid mixture lacking the respective AAs serving as precursors. Functional neuroimaging has given insights into differential brain activation patterns and functions depending on the tasks performed, pharmacological treatments or specific disorders. Such research has shed light on the function of many brain areas as well as their interactions. The combination of AA challenge approaches with neuroimaging techniques has been subject of numerous studies. Overall, the studies conducted in this particular field of research have shown that AA challenge techniques are valid and effective research tools that allow the investigation of serotonergic and dopaminergic systems without causing serious side effects or long-term damage to the subjects. In this review, we will present an overview of the results obtained so far and discuss the implications of these findings as well as open questions that remain to be answered.

Effects of a short-term reduction in brain serotonin synthesis on the availability of the soluble leptin receptor in healthy women.

Serotonin (5-HT) and the hormone leptin have been linked to the underlying neurobiology of appetite regulation with evidence coming from animal and cellular research, but direct evidence linking these two pathways in humans is lacking. We examined the effects of reduced brain 5-HT synthesis due to acute tryptophan depletion (ATD) on levels of soluble leptin receptor (sOb-R), the main high-affinity leptin binding protein, in healthy adults using an exploratory approach. Women, but not men, showed reduced sOb-R concentrations after ATD administration. With females showing reduced baseline levels of central 5-HT synthesis compared to males diminished brain 5-HT synthesis affected the leptin axis through the sOb-R in females, thereby potentially influencing their vulnerability to dysfunctional appetite regulation and co-morbid mood symptoms.

Change in electrodermal activity after acute tryptophan depletion associated with aggression in young people with attention deficit hyperactivity disorder (ADHD).

We investigated the impact of acute tryptophan depletion (ATD) and reduced brain serotonin synthesis on physiological arousal in 15 young people with ADHD participating in an aggression-inducing game. ATD was not associated with altered physiological arousal, as indexed by electrodermal activity (EDA). Baseline aggression was negatively correlated with the mean ATD effect on EDA. In accordance with the low arousal theory related to aggressive behavior, subjects with reduced physiological responsiveness/lower electrodermal reactivity to ATD tended to display elevated externalizing behavior.