The Tower of London task in children and adolescents with neuropsychiatric disorders.

The Tower of London, Drexel Version, Second Edition (TOL-DX) is purported to measure multiple aspects of executive functions, although it also possesses inherent non-executive demands. Such complexity makes it useful in detecting impairment but difficult in interpreting the neurocognitive cause of impairment, particularly in children. This study investigated the developmental, neurocognitive, and symptom correlates of the TOL-DX in children and adolescents with neuropsychiatric disorders. Two-hundred and thirty-three children and adolescents (7-21 years old) completed the TOL-DX during a neuropsychological evaluation as part of clinical care within a children's psychiatric hospital. Pearson correlation, regression models, and receiver operating characteristic curve (ROC) analyses examined the association among variables. Visuospatial and executive functions (EF) were most consistently related to total moves, execution time, and violations. TOL-DX variables were associated with attention in younger participants and EF in older participants. No TOL-DX scores were related to parent-reported symptoms. The TOL-DX possesses inherent visuospatial and attention/executive demands in children and adolescents which are difficult to differentiate, differ by age group, and not associated to clinical symptoms. Taken together, the TOL-DX is complex to interpret, but psychometrically sound and sensitive to neurocognitive impairment in children and adolescents with transdiagnostic neuropsychiatric disorders.

Frontoparietal beta event characteristics are associated with early life stress and psychiatric symptoms in adults.

Recent work has found that the presence of transient, oscillatory burst-like events, particularly within the beta band (15-29 Hz), is more closely tied to disease state and behavior across species than traditional electroencephalography (EEG) power metrics. This study sought to examine whether features of beta events over frontoparietal electrodes were associated with early life stress (ELS) and the related clinical presentation. Eighteen adults with documented ELS (n = 18; ELS + ) and eighteen adults without documented ELS (n = 18; ELS-) completed eyes-closed resting state EEG as part of their participation in a larger childhood stress study. The rate, power, duration, and frequency span of transient oscillatory events were calculated within the beta band at five frontoparietal electrodes. ELS variables were positively associated with beta event rate at Fp2 and beta event duration at Pz, in that greater ELS was associated with higher resting rates and longer durations. These beta event characteristics were used to successfully distinguish between ELS + and ELS- groups. In an independent clinical dataset (n = 25), beta event power at Pz was positively correlated with ELS. Beta events deserve ongoing investigation as a potential disease marker of ELS and subsequent psychiatric treatment outcomes.

Childhood stress, gender, and cognitive control: Midline theta power.

The emergence of psychiatric symptoms is a common consequence of childhood stress exposure. However, there are a dearth of reliable clinical hallmarks or physiological biomarkers to predict post-trauma symptom emergence. The objective of this study was to examine if childhood stressors and stress-related symptoms are associated with altered midline theta power (MTP) during cognitive control demands, and how these associations interact with gender and early adversity. N = 53 children (ages 9-13 years old) from a longitudinal study of children maltreated during early childhood and non-maltreated children participated in this study. EEG recorded neural activity during a Zoo-Themed Go/No-Go task. Stress-related symptoms, recent stressful events, and other adversity experiences were identified. MTP was analyzed with clinical variables in a series of follow-up analyses. The number of stressors in the past six months was negatively correlated with MTP in those with low preschool adversity, but not in those with high preschool adversity. MTP was higher in girls than in boys, and the associations of MTP with stressors and symptoms were moderated by gender. MTP was negatively associated with stressors in the past six months in girls, while in boys, MTP was associated with stress-related symptoms. Childhood stressful events were associated with reduced MTP during cognitive control demands, and this was finding was moderated by gender and early life adversity. These preliminary findings suggest that boys and girls may process stressful experiences in distinct ways, and preschool adversity may potentially blunt the interaction between current stress and neural dynamics. However, ongoing investigation is needed.

Christianson Syndrome across the Lifespan: An International Longitudinal Study in Children, Adolescents, and Adults.

Mutations in the X-linked endosomal Na+/H+ Exchanger 6 (NHE6) causes Christianson Syndrome (CS). In the largest study to date, we examine genetic diversity and clinical progression, including cerebellar degeneration, in CS into adulthood. Data were collected as part of the International Christianson Syndrome and NHE6 (SLC9A6) Gene Network Study. Forty-four individuals with 31 unique NHE6 mutations, age 2 to 32 years, were followed prospectively, herein reporting baseline, 1-year follow-up, and retrospective natural history. We present data on the CS phenotype with regard to physical growth, adaptive and motor regression, and across the lifespan, including information on mortality. Longitudinal data on body weight and height were examined using a linear mixed model: the rate of growth across development was slow and resulted in prominently decreased age-normed height and weight by adulthood. Adaptive functioning was longitudinally examined: a majority of adult (18+ years) participants lost gross and fine motor skills over a 1-year follow-up. Previously defined core diagnostic criteria for CS (present in >85%) - namely nonverbal status, intellectual disability, epilepsy, postnatal microcephaly, ataxia, hyperkinesia - were universally present in age 6 to 16; however, an additional core feature of high pain tolerance was added (present in 91%), and furthermore, evolution of symptoms were noted across the lifespan, such that postnatal microcephaly, ataxia and high pain threshold were often not apparent prior to age 6, and hyperkinesis decreased after age 16. While neurologic exams were consistent with cerebellar dysfunction, importantly, a majority of individuals (>50% older than 10) also had corticospinal tract abnormalities. Three participants died during the period of the study. In this large and longitudinal study of CS, we begin to define the trajectory of symptoms and the adult phenotype, thereby identifying critical targets for treatment.

Pre-treatment frontal beta events are associated with executive dysfunction improvement after repetitive transcranial magnetic stimulation for depression: A preliminary report.

Repetitive transcranial magnetic stimulation (rTMS) is an established clinical treatment for major depressive disorder (MDD) that has also been found to improve aspects of executive functioning. The objective of this study was to examine whether oscillatory burst-like events within the beta band (15-29 Hz) prior to treatment could predict subsequent change in self-reported executive dysfunction (EDF) across a clinical course of rTMS for MDD. Twenty-eight adults (64% female) with MDD completed the self-report Frontal Systems Behavior Scale (FrSBe) and provided eyes-closed resting-state electroencephalography (EEG) before and after a clinical course of rTMS therapy for primary MDD. The rate, power, duration, and frequency span of transient EEG measured oscillatory beta events were calculated. Events within delta/theta and alpha bands were examined to assess for beta specificity. After controlling for improvement in primary depressive symptoms, a lower rate of beta events at F3, Fz, F4, and Cz prior to rTMS treatment was associated with a larger improvement in EDF after rTMS treatment. In addition, a decrease in beta event rate at Fz pre-to-post treatment was associated with a larger improvement in EDF after treatment. Results were largely specific to the beta band. In this study, the rate of frontrocentral beta events prior to treatment significantly predicted the likelihood of subsequent improvement in EDF symptoms following a clinical course of rTMS for MDD. These preliminary findings suggest the potential utility of EEG measured beta events and rTMS for targeting EDF across an array of neuropsychiatric disorders.

Moderators of Age of Diagnosis in > 20,000 Females with Autism in Two Large US Studies.

The objective of this study was to determine the clinical features that moderate a later age at ASD diagnosis in females in a large sample of females with ASD. Within two large and independent ASD datasets (> 20,000 females), females were first diagnosed with ASD 14-months later relative to males. This later age at diagnosis was moderated by a mild or atypical presentation, wherein repetitive behaviors were limited, IQ and language were broadly intact, and recognized symptoms emerged later in development. Females are at risk for a later age at ASD diagnosis and treatment implementation, and modification of early childhood ASD screening methods for females may be warranted.

Parental age and autism severity in the Rhode Island Consortium for Autism Research and Treatment (RI-CART) study.

Advanced parental age at offspring birth has been associated with autism spectrum disorder (ASD). The objective of the current study was to investigate associations between parental age at birth and autism severity. The Rhode Island Consortium for Autism Research and Treatment (RI-CART) study represents a community-based sample with a range of autism severity, including participants with and without ASD. This study involved participants (n = 1178) enrolled in RI-CART with available mother and father ages at birth. Primary data points included the age of mother and father at the participant's birth and results from the Autism Diagnostic Observation Schedule - Second Edition (ADOS-2). Mothers were 1.7 years older at the time of birth of the child with ASD, as compared to mothers of offspring without ASD. Fathers of children with ASD were 1.6 years older at the time of birth than fathers of children without ASD. The age of both parents at offspring birth displayed a positive, statistically significant association with overall ASD severity and the severity of restricted/repetitive behaviors. This finding was driven by the association between parental age and the severity of compulsions or rituals. Intelligence and adaptive functioning did not moderate the relationship between parental age and ASD severity. This study extends prior research to show that advanced parental age at birth is associated with the severity as well as the presence of ASD in offspring.

Cognitive Control Deficits in Depression: A Novel Target to Improve Suboptimal Outcomes in Childhood.

Cognitive control deficits are one of three primary endophenotypes in depression, and the enhanced targeting of these deficits in clinical and research work is expected to lead to improved depression outcomes. Cognitive control is a set of self-regulatory processes responsible for goal-oriented behavior that predicts clinical/functional outcomes across the spectrum of brain-based disorders. In depression, cognitive control deficits emerge by the first depressive episode, persist during symptom remission, and worsen over the course of depression. In addition, the presence of these deficits predicts a poor response to evidence-based depression treatments, including psychotherapy and antidepressant medication. This is particularly relevant to childhood depression, as 1%-2% of children are diagnosed with depression, yet there are very limited evidence-based treatment options. Cognitive control deficits may be a previously underaddressed factor contributing to poor outcomes, although there remains a dearth of research examining the topic. The investigators describe the prior literature on cognitive control in depression to argue for the need for increased focus on this endophenotype. They then describe cognitive control-focused clinical and research avenues that would likely lead to improved treatments and outcomes for this historically undertreated aspect of childhood depression.

Human neurons from Christianson syndrome iPSCs reveal mutation-specific responses to rescue strategies.

Christianson syndrome (CS), an X-linked neurological disorder characterized by postnatal attenuation of brain growth (postnatal microcephaly), is caused by mutations in SLC9A6, the gene encoding endosomal Na+/H+ exchanger 6 (NHE6). To hasten treatment development, we established induced pluripotent stem cell (iPSC) lines from patients with CS representing a mutational spectrum, as well as biologically related and isogenic control lines. We demonstrated that pathogenic mutations lead to loss of protein function by a variety of mechanisms: The majority of mutations caused loss of mRNA due to nonsense-mediated mRNA decay; however, a recurrent, missense mutation (the G383D mutation) had both loss-of-function and dominant-negative activities. Regardless of mutation, all patient-derived neurons demonstrated reduced neurite growth and arborization, likely underlying diminished postnatal brain growth in patients. Phenotype rescue strategies showed mutation-specific responses: A gene transfer strategy was effective in nonsense mutations, but not in the G383D mutation, wherein residual protein appeared to interfere with rescue. In contrast, application of exogenous trophic factors (BDNF or IGF-1) rescued arborization phenotypes across all mutations. These results may guide treatment development in CS, including gene therapy strategies wherein our data suggest that response to treatment may be dictated by the class of mutation.

A preliminary investigation of childhood anxiety/depressive symptomatology and working memory across multiple units of analysis.

This exploratory study examined multiple units of working memory (WM) analysis in a transdiagnostic, treatment-seeking, pediatric sample. This included a) an electroencephalography marker of WM (coupling of theta and gamma oscillations [i.e., theta-gamma coupling] in frontal brain regions), b) WM test performance, and c) parent-reported WM symptoms. A composite score combining each of these units of analysis correlated with self-reported depressive and anxiety symptoms, with only theta-gamma coupling independently predicted anxiety/depressive symptoms. Results confirm prior findings on the association between WM and anxiety/depression, although the majority of this variance was explained by frontal theta-gamma coupling during WM demands.

Autism Heterogeneity in a Densely Sampled U.S. Population: Results From the First 1,000 Participants in the RI-CART Study.

The objective of this study was to establish a large, densely sampled, U.S. population-based cohort of people with autism spectrum disorder (ASD). The Rhode Island Consortium for Autism Research and Treatment (RI-CART) represents a unique public-private-academic collaboration involving all major points of service for families in Rhode Island affected by ASD. Diagnosis was based on direct behavioral observation via the Autism Diagnostic Observation Schedule, Second Edition. For the first 1,000 participants, ages ranged from 21 months to 64 years. Using Geographic Information System and published prevalence rates, the overall cohort is estimated to represent between 20% and 49% of pediatric age persons in Rhode Island with ASD, with demographics representative of U.S. Census. We observed a high rate of co-occurring medical and psychiatric conditions in affected individuals. Among the most prominent findings of immediate clinical importance, we found that females received a first diagnosis of ASD at a later age than males, potentially due to more advanced language abilities in females with ASD. In summary, this is the first analysis of a large, population-based U.S. cohort with ASD. Given the depth of sampling, the RI-CART study reflects an important new resource for studying ASD in a representative U.S. population. Psychiatric and medical comorbidities in ASD constitute a substantial burden and warrant adequate attention as part of overall treatment. Our study also suggests that new strategies for earlier diagnosis of ASD in females may be warranted. Autism Res 2020, 13: 474-488. © 2020 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: The Rhode Island Consortium for Autism Research and Treatment (RI-CART) represents a unique public-private-academic collaboration involving all major points of service for families in Rhode Island affected by autism spectrum disorder (ASD). In this article, we provide results from the first 1,000 participants, estimated to represent >20% of affected families in the state. Importantly, we find a later age at first diagnosis of ASD in females, which potentially calls attention to the need for improved early diagnosis in girls. Also, we report a high rate of co-occurring medical and psychiatric conditions in affected individuals.

Neurocognitive heterogeneity across the spectrum of psychopathology: need for improved approaches to deficit detection and intervention.

Neurocognition is one of the strongest predictors of clinical and functional outcomes across the spectrum of psychopathology, yet there remains a dearth of unified neurocognitive nosology and available neurocognition-targeted interventions. Neurocognitive deficits manifest in a transdiagnostic manner, with no psychiatric disorder uniquely affiliated with one specific deficit. In fact, recent research has identified that essentially all investigated disorders are comprised of 3-4 neurocognitive profiles. This within-disorder neurocognitive heterogeneity has hampered the development of novel, neurocognition-targeted interventions, as only a portion of patients with any given disorder possess neurocognitive deficits that would warrant neurocognitive intervention. The development of criteria and terminology to characterize these neurocognitive deficit syndromes would provide clinicians with the opportunity to more systematically identify and treat their patients and provide researchers the opportunity to develop neurocognition-targeted interventions for patients. This perspective will summarize recent work and discuss possible approaches for neurocognition-focused diagnosis and treatment in psychiatry.

Measurement of executive functioning with the National Institute of Health Toolbox and the association to anxiety/depressive symptomatology in childhood/adolescence.

INTRODUCTION: Despite preliminary research, there remain inconsistent findings with regard to the role of executive functioning (EF) deficits in childhood anxiety and depression. This report examined the association of The National Institute of Health (NIH) Toolbox to clinical neuropsychological measures and to childhood, anxiety/depressive symptomatology. Methods: One-hundred eight children and adolescents completed the three EF measures from the NIH Toolbox (List Sorting Working Memory Test [LSWMT], Dimensional Change Card Sorting Test [DCCST], and Flanker Test of Attention and Inhibition [Flanker]) in an outpatient neuropsychology program. These tests were compared to established measures of EF in terms of linear correlations and detection of impairment. Heaton's Global Deficit Score (GDS) was utilized to calculate impairment. The Toolbox-EF measures were paired with parent-reported EF symptoms (Behavior Rating Inventory of Executive Function [BRIEF2]) to identify the role of EF in childhood anxiety/depressive symptomatology. RESULTS: Toolbox-EF measures displayed medium sized correlations with their clinically comparable counterparts, and generally did not differ in their detection of impairment. Toolbox-GDS was associated with depression diagnosis and clinically significant child-reported anxiety and depressive symptoms. Together, Toolbox/BRIEF2 accounted for 26.8-30.9% of elevated depressive symptom variance, but only 13.2-14% of elevated anxiety symptom variance. Further, EF impairment was associated with depression across self report, parent report, and clinical diagnosis. DISCUSSION: The NIH Toolbox-EF measures display comparable psychometric properties to clinically available EF measures in a pediatric (primarily psychiatric) neuropsychology setting. The Toolbox appears to display an appropriate ability to detect EF deficits secondary to self-reported depression in childhood.

GPT2 mutations in autosomal recessive developmental disability: extending the clinical phenotype and population prevalence estimates.

The glutamate pyruvate transaminase 2 (GPT2) gene produces a nuclear-encoded mitochondrial enzyme that catalyzes the reversible transfer of an amino group from glutamate to pyruvate, generating alanine and alpha-ketoglutarate. Recessive mutations in GPT2 have been recently identified in a new syndrome involving intellectual and developmental disability (IDD), postnatal microcephaly, and spastic paraplegia. We have identified additional families with recessive GPT2 mutations and expanded the phenotype to include small stature. GPT2 loss-of-function mutations were identified in four families, nine patients total, including: a homozygous mutation in one child [c.775T>C (p.C259R)]; compound heterozygous mutations in two siblings [c.812A>C (p.N271T)/c.1432_1433delGT (p.V478Rfs*73)]; a novel homozygous, putative splicing mutation [c.1035C>T (p.G345=)]; and finally, a recurrent mutation, previously identified in a distinct family [c.1210C>T (p.R404*)]. All patients were diagnosed with IDD. A majority of patients had remarkably small stature throughout development, many < 1st percentile for height and weight. Given the potential biological function of GPT2 in cellular growth, this phenotype is strongly suggestive of a newly identified clinical susceptibility. Further, homozygous GPT2 mutations manifested in at least 2 of 176 families with IDD (approximately 1.1%) in a Pakistani cohort, thereby representing a relatively common cause of recessive IDD in this population, with recurrence of the p.R404* mutation in this population. Based on variants in the ExAC database, we estimated that approximately 1 in 248 individuals are carriers of moderately or severely deleterious variants in GPT2.

Longitudinal MRI findings in patient with SLC25A12 pathogenic variants inform disease progression and classification.

Aspartate-glutamate carrier 1 (AGC1) is one of two exchangers within the malate-aspartate shuttle. AGC1 is encoded by the SLC25A12 gene. Three patients with pathogenic variants in SLC25A12 have been reported in the literature. These patients were clinically characterized by neurodevelopmental delay, epilepsy, hypotonia, cerebral atrophy, and hypomyelination; however, there has been discussion in the literature as to whether this hypomyelination is primary or secondary to a neuronal defect. Here we report a 12-year-old patient with variants in SLC25A12 and magnetic resonance imaging (MRI) at multiple ages. Novel compound heterozygous, recessive variants in SLC25A12 were identified: c.1295C>T (p.A432V) and c.1447-2_1447-1delAG. Clinical presentation is characterized by severe intellectual disability, nonambulatory, nonverbal status, hypotonia, epilepsy, spastic quadriplegia, and a happy disposition. The serial neuroimaging findings are notable for cerebral atrophy with white matter involvement, namely, early hypomyelination yet subsequent progression of myelination. The longitudinal MRI findings are most consistent with a leukodystrophy of the leuko-axonopathy category, that is, white matter abnormalities that are most suggestive of mechanisms that result from primary neuronal defects. We present here the first case of a patient with compound heterozygous variants in SLC25A12, including brain MRI findings, in the oldest individual reported to date with this neurogenetic condition.

Measurement and Modulation of Working Memory-Related Oscillatory Abnormalities.

Despite the critical role of working memory (WM) in neuropsychiatric conditions, there remains a dearth of available WM-targeted interventions. Gamma and theta oscillations as measured with electroencephalography (EEG) or magnetoencephalography (MEG) reflect the neural underpinnings of WM. The WM processes that fluctuate in conjunction with WM demands are closely correlated with WM test performance, and their EEG signatures are abnormal in several clinical populations. Novel interventions such as transcranial magnetic stimulation (TMS) have been shown to modulate these oscillations and subsequently improve WM performance and clinical symptoms. Systematically identifying pathological WM-related gamma/theta oscillatory patterns with EEG/MEG and developing ways to target them with interventions such as TMS is an active area of clinical research. Results hold promise for enhancing the outcomes of our patients with WM deficits and for moving the field of clinical neuropsychology towards a mechanism-based approach.

Complex Neurological Phenotype in Female Carriers of NHE6 Mutations.

Mutations in NHE6 (also termed SLC9A6) cause the X-linked neurological disorder Christianson syndrome (CS) in males. The purpose of this study was to examine the phenotypic spectrum of female carriers of NHE6 mutations. Twenty female carriers from 9 pedigrees were enrolled, ranging from approximately age 2 to 65. A subset of female carriers was assessed using standardized neuropsychological measures. Also, the association of NHE6 expression with markers of brain age was evaluated using 740 participants in the Religious Orders Study (ROS) and Rush Memory and Aging Project (MAP). A majority, but not all, female carriers demonstrated a deficit in at least one neurocognitive domain (85%). A recognizable neuropsychological profile emerged, revealing impairments in visuospatial function, attention, and executive function. Common neuropsychiatric diagnoses included: intellectual disability/developmental delay (20%), learning difficulties (31%), speech/language delays (30%), and attention-deficit/hyperactivity disorder (20%). Notable neurological diagnoses in aging CS female carriers include corticobasal degeneration and atypical parkinsonism. In postmortem brains from the ROS/MAP dataset of normal and pathological aging, decreased NHE6 expression was correlated with greater tau deposition. Our study provides an examination of the phenotypic range in female carriers of NHE6 mutations. The findings indicate that NHE6-related disease in females represents a new neurogenetic condition.

Prevalence of low test scores in a pediatric psychiatric inpatient population: Applying multivariate base rate analyses.

The understanding of neuropsychological functioning in pediatric psychiatric inpatient populations is growing, but limited, resulting in interpretive challenges. This study examined the application of multivariate base rate (MVBR) analysis in a clinical sample to appraise its utility in characterizing the frequency of low scores, as well as predictors of low scores, when using a flexible test battery. Participants included 99 children from a psychiatric inpatient unit referred for neuropsychological testing. Children hospitalized with psychiatric disorders exhibited high rates of low scores at varying criteria across the battery of tests. Hierarchical multiple regression analyses revealed that after accounting for demographic and psychiatric factors, intellectual functioning accounted for approximately 26% of the variance in observed low scores. The results suggest that a substantial percentage of this population produces low scores on neuropsychological testing and, consistent with prior research, intellectual functioning is strongly associated with low score frequency. To our knowledge, this is the first study to examine the clinical application of MVBR analysis in a pediatric psychiatric inpatient population using a flexible test battery. Taken together, this investigation highlights the potential clinical utility of MVBR analysis when interpreting neuropsychological performance in clinical pediatric populations.