Significant age by childhood trauma interactions on grey matter volumes: A whole brain VBM analysis.

BACKGROUND: Childhood trauma is deleterious to long term brain development. The changes are variable, and depend on gender, age and the nature of the trauma. In this exploratory analysis, we investigated the effects of exposure to emotional trauma on grey matter (GM) volumes in adolescent females. METHODS: We explored GM volumes in non-clinical females aged 12-17 years who had been exposed to either higher (HET; N = 75) or minimal (MET; N = 127) emotional trauma. High-resolution T1-weighted structural images were analysed with an optimised FSL-VBM protocol. The General Linear Model was run on HET versus MET with continuous age as an interaction. Mean GM volumes were extracted from significant corrected age interaction statistical maps and scrutinised with SPSS®. RESULTS: We observed greater HET*age than MET*age interactions (corrected p-value = 0.0002), in 4 separate bilateral cortical regions associated with mood disorders. Scrutiny of these regions showed significant GM volume enlargements in the early adolescent HET group (p = 0.017) and reductions in the late adolescent HET group (p < 0.0001). Notably, there were no differences in middle adolescence (p > 0.05). LIMITATIONS: Causality cannot be inferred from this cross-sectional study and the onset of trauma cannot be determined using retrospective measures. CONCLUSIONS: Whilst GM volumes diminish from early adolescence onwards, our results show that HET impacts this brain development, perhaps first via unstable adaptative mechanisms, followed by maladaptive processes in late adolescence. This suggests that compromises of emotional and cognitive self-regulation in mood disorders may underpin the structural abnormalities observed across multiple brain regions in these teenage girls.

Lithium replacement dose recommendations using Monte Carlo simulations.

OBJECTIVES: Missed medication doses are a common clinical problem, and cause consternation when prescribing lithium because its plasma levels must be kept within a narrow therapeutic window. Therefore, this study set out to determine the potential impact of missed lithium doses on its pharmacokinetics, and to explore the optimal compensatory dosing scheme. This is difficult to determine clinically and in research because of ethical constraints and therefore we modelled the effects using simulations. METHODS: Monte Carlo simulations were used to simulate lithium concentrations under different missed dose scenarios. For patients with normal renal function, the optimal replacement dosing scheme was selected based on the lowest percentage of deviation from the full adherence scenario. However, for patients with renal impairment the appropriate dosing schedule was selected based on the lowest number of simulated concentrations above the upper range of 1.2 mEq/L. RESULTS: The impact of a missed lithium dose depended on its daily dose. The higher the daily dose, the higher the deviation from full adherence. In patients with normal renal function, replacement with a regular dose was most appropriate. But in patients with renal impairment, replacement with a partial dose appeared to be most suitable. CONCLUSIONS: This study has enabled insights into the optimal suitable lithium replacement dosing schemes for patients with normal renal function and renal impairment. These proposed schemes can be used cautiously in clinical practice in conjunction with clinician judgment and can also be used as a basis for future clinical research.

Novel insights into irritability: the relationship between subjective experience, age and mood.

BACKGROUND: The relationship between irritability as a subjective experience and the behavioural indicators typically used to measure the construct are not known. Its links to mood, and contextual relationships, vary with age and are yet to be thoroughly examined. AIMS: First, to interrogate the relationship between the subjective experience of irritability and mood, and that with its behavioural indicators. Second, to determine how these relationships vary with age and over time. METHOD: This study examined data from a previous clinical trial of adolescents and young adults (N = 82) with bipolar disorder, who received a psychological intervention over 18 months. Participants completed a battery of questionnaires, which included assessments of irritability. Analyses of covariance were conducted to examine the interaction between mood symptoms, subjective measures of irritability, behavioural measures of irritability and age over time. RESULTS: Subjective irritability scores differed significantly over time when controlling for manic, but not depressive, symptom scores. Further, subjective irritability significantly differed when controlling for behavioural measures of irritability (temper outbursts and argumentativeness). There were significant interactions between scores of depressive symptoms, temper outbursts and subjective irritability with age, wherein younger participants showed no correlation between depressive symptoms and temper outbursts. In addition, younger participants showed lower correlations between subjective irritability and both depressive and temper outburst scores, than older participants. CONCLUSIONS: Subjective irritability is linked to mood morbidity and behavioural outbursts, and these relationships are contingent on age. Our novel findings suggest that subjective irritability should be assessed in greater detail in patients with mood disorders.

Profiling rTMS: A critical response.

This article is a detailed response to the criticisms levelled by the authors of an accompanying viewpoint, which claims that the positioning of repetitive transcranial magnetic stimulation (rTMS) in the 2020 Royal Australian and New Zealand College of Psychiatrists (RANZCP) clinical practice guidelines for the management mood disorders (MDcpg2020) is incorrect. We, the authors of the MDcpg2020, strongly refute these assertions and argue that first we have determined the positioning of rTMS using the same criteria as those applied to other treatments for depression. Second, in accordance with National Health and Medical Research Council (NHMRC) guidelines, the processes by which we have developed the MDcpg2020 have been guided by best practice and have been overseen throughout by the RANZCP. Third, our objective and detailed examination of the relevant research has shown that the evidence needed to support the positioning of rTMS alongside standard therapies for depression is severely deficient. And therefore, as a consequence, we set out clearly both our logic and reasoning with respect to interpreting rTMS data and outline our evidence-informed position in which rTMS remains a potential alternative therapy that can be considered in certain clinical circumstances once both suitable psychological and pharmacological treatments have been trialled. We also discuss why, until further research is conducted, rTMS is perhaps best regarded as an experimental therapy and an investigational tool, and to assist in this regard, we propose a framework for consideration by those conducting rTMS studies in the future. Thus, based on current knowledge, we conclude that rTMS does not have a sufficient evidence base to warrant recognition as a standard therapy for depression alongside established treatments such as psychological interventions, pharmacotherapy, and electroconvulsive therapy. Furthermore, there is no clinical profile for depressed patients that might benefit from rTMS and therefore tolerability alone is not good enough reason to promote rTMS in the management of major depression.

Irritability and mood symptoms in adolescent girls: Trait anxiety and emotion dysregulation as mediators.

BACKGROUND: Irritability is a common symptom in youth that is thought to be predictive of mood disorders. Its effects on mood are likely to be age-dependent, with direct and indirect mediators. We assessed age-related effects and mediators of irritability in adolescent girls with subthreshold depressive and manic symptoms. METHODS: We analysed the irritability item from the Mood Disorder Questionnaire in 3 cohorts of girls aged 12-18years (N=229); 12-13years (N=82); 14-15years (N=68); and 16-18years (N=79). They also completed mood, anxiety and emotion regulation questionnaires. MANOVA, correlations and bootstrapped mediation analyses were performed with SPSS®v25 and Hayes Processv3.5®. RESULTS: Overall, irritable girls had higher depressive and manic symptoms, trait anxiety and emotion dysregulation than those who were not irritable. Significantly higher rates of irritability were observed in mid-adolescents (aged 14-15years; p = 0.001). Notably, irritability exerted effects on depressive symptoms via trait anxiety, non-acceptance of emotions and dysregulation in emotion clarity throughout adolescence. However, irritability directly exerted effects on manic symptoms in mid-adolescence but in older adolescents, their relationship was indirect via impulse control dysregulation. LIMITATIONS: The cross-sectional design and non-clinical sample limit generalisability of our findings. CONCLUSIONS: Irritability is involved in subthreshold depressive symptoms, via trait anxiety and perceptual emotion dysregulation. On the other hand, irritability is directly and indirectly associated with subthreshold manic symptoms via dysregulated impulse control depending on age. Therefore, screening for irritability, trait anxiety and emotion dysregulation throughout adolescence may facilitate the early detection of subthreshold depressive and manic symptoms, and the implementation of preventive strategies.

Interactions of OXTR rs53576 and emotional trauma on hippocampal volumes and perceived social support in adolescent girls.

Oxytocin (OXT) is a neuropeptide involved in social behaviour and is sensitive to environmental influences to alter individual vulnerability or resilience to stress resulting in both negative and positive outcomes. The effects of the OXT receptor (OXTR) single nucleotide polymorphism (SNP) rs53576 on hippocampal and amygdala structure and functions in adults are differentially associated with susceptibility to adversity and social behaviours, but this evidence is lacking in healthy adolescents. Adolescence is a developmental period characterised by neurobiological and psychosocial changes resulting in higher susceptibility to mood disorders, particularly among girls. As the brain is highly plastic at this stage, to understand psychosocial and emotional development, clarity of the interactions between rs53576 and adversity on hippocampal and amygdala volumes and social behaviours is needed. In this study, we investigated the interactions between rs53576 and emotional trauma (ET) exposure on hippocampal and amygdala volumes of adolescent girls, and associations with parenting style, perceived social support and bullying behaviour. Based on an unbiased and corrected analytical approach, we found smaller left hippocampal volumes in higher (hET) compared to minimally (mET) exposed AA homozygotes, but no differences in G allele carriers nor in the amygdala. Within the mET AA group, larger volumes were associated with peer perceived social support, but in their hET counterparts, smaller volumes were associated with familial perceived social support. This evidence supports an important role for the hippocampus in social behaviours but extends current knowledge to suggest that hippocampal social behavioural features are contextually dependent on rs53576.

Modelling resilience in adolescence and adversity: a novel framework to inform research and practice.

Recent conceptualisations of resilience have advanced the notion that it is a dynamic and multifaceted construct. However, its adaptive components, especially those forged by adversity, have not been fully realised, and its neurobiological and psychosocial underpinnings are yet to be meaningfully integrated. In part, this is because a developmental perspective is often neglected in the formulation of resilience. In this review, we consider the findings of resilience research, with a specific emphasis on the developmental period of adolescence. To bridge the gaps in our current understanding, we propose a model of resilience that is predicated on experiencing adversity. Specifically, our model provides a sophisticated insight into the components of resilience, which, together with intrinsic features, involves facilitation of, and skill acquisition via strengthening processes we term tempering and fortification. The model also points to the potential trajectories of adversity-driven resilience and forms the basis of a framework that allows for individual variance in resilience, and the identification of both neurobiological and psychosocial targets for prevention and therapeutic interventions.

Understanding trauma-induced hippocampal subfield volume changes in the context of age and health.

There is an urgent need to integrate the findings converging from different perspectives examining hippocampal volume changes both overall but in particular within its subfields in relation to childhood trauma and illness. We comment on a recent paper's findings and link these to our own research in an effort to provide impetus to this endeavor.

Effect of stress gene-by-environment interactions on hippocampal volumes and cortisol secretion in adolescent girls.

OBJECTIVE: Adolescence is a time of increased susceptibility to environmental stress and mood disorders, and girls are particularly at risk. Genes interacting with the environment (G × E) are implicated in hypothalamic-pituitary-adrenal axis dysregulation, hippocampal volume changes and risk or resilience to mood disorders. In this study, we assessed the effects of stress system G × E interactions on hippocampal volumes and cortisol secretion in adolescent girls. METHODS: We recruited 229 girls aged 12-18 years, and scans were obtained from 202 girls. Of these, 76 had been exposed to higher emotional trauma (abuse or neglect). Hippocampal volumes were measured using Freesurfer and high-resolution structural magnetic resonance imaging scans. Saliva samples were collected for measurement of cortisol levels and genotyping of stress system genes: FKBP5, NR3C1 (both N = 194) and NR3C2 ( N = 193). RESULTS: Among girls with the 'G' allelic variant of the NR3C1 gene, those who had been exposed to higher emotional trauma had significantly smaller left hippocampal volumes ( N = 44; mean = 4069.58 mm3, standard deviation = 376.99) than girls who had been exposed to minimal emotional trauma with the same allelic variant ( N = 69; mean = 4222.34 mm3, standard deviation = 366.74). CONCLUSION: In healthy adolescents, interactions between emotional trauma and the 'protective' NR3C1 'GG' variant seem to induce reductions in left hippocampal volumes. These G × E interactions suggest that vulnerability to mood disorders is perhaps driven by reduced 'protection' that may be specific to emotional trauma. This novel but preliminary evidence has implications for targeted prevention of mood disorders and prospective multimodal neuroimaging and longitudinal studies are now needed to investigate this possibility.

The effects of childhood trauma on adolescent hippocampal subfields.

OBJECTIVE: Mood disorders are more common among girls and typically emerge during adolescence. The precise reasons for this are unknown, but among the many mechanisms implicated are stress-induced hippocampal structural changes during this developmental stage. The hippocampus is a complex structure comprised of subfields that develop differentially and respond variably to stress and childhood adversity, both of which are risk factors for mood disorders. To better understand vulnerability to mood disorders, we investigated a cohort of adolescent girls and determined volumetric changes in their hippocampal subfields to elucidate the potential effects of childhood trauma. METHODS: Of the 229 participants, 201 girls (aged 12-17 years) fulfilled our analysis inclusion criteria. Of these, 76 had been exposed to higher emotional trauma (emotional abuse or neglect). The girls underwent high-resolution structural magnetic resonance imaging scans, and hippocampal subfield volumes were measured using FreeSurfer. We compared hippocampal subfield volumes in those exposed to higher emotional trauma and those exposed to minimal emotional trauma, at three time-points of adolescent development: early (12-13 years), mid (14-15 years) and late (16-17 years). RESULTS: Mid-adolescent girls exposed to higher emotional trauma had significantly smaller left CA3 volumes than minimal emotional trauma girls ( p = 0.028). Within the minimal emotional trauma group, mid-adolescents had significantly larger left CA3 volumes than early ( p = 0.034) and late ( p = 0.036) adolescents. Within the higher emotional trauma group, early adolescents had significantly larger left CA3 volumes than late adolescents ( p = 0.036). CONCLUSION: In our exploratory study, we observed higher emotional trauma-induced volume changes in the left CA3 hippocampal subfield, which varied depending on age, and may ultimately produce deficits in behavioural, cognitive and emotional processes. We propose that these changes (1) may provide a mechanism through which vulnerability to mood disorders may be increased in adolescent girls, and (2) may signal the best times to implement targeted prevention interventions.

Treatment-resistant depression: problematic illness or a problem in our approach?

Treatment-resistant depression is widely defined as non-response to two 'adequate' courses of treatment. However, the definitions of treatment and depression are inconsistent reflecting gaps in our understanding. We argue that a failure to respond is often the result of administering inappropriate treatment, which occurs principally because of paradigm failure.Declaration of interestNone.

Primary Prevention of Mood Disorders: A Primary Concern That Requires Urgent Action.

Among mental disorders in youth, mood disorders contribute the greatest burden. With a multifactorial etiology and a developmental trajectory, mood disorders have myriad manifestations; hence, preventative approaches have to be equally diverse.