Investigating bullying as a predictor of suicidality in a clinical sample of adolescents with Autism Spectrum Disorder

For typically developing adolescents, being bullied is associated with increased risk of suicidality. Although adolescents with autism spectrum disorder (ASD) are at increased risk of both bullying and suicidality, there is very little research that examines the extent to which an experience of being bullied may increase suicidality within this specific population. To address this, we conducted a retrospective cohort study to investigate the longitudinal association between experiencing bullying and suicidality in a clinical population of 680 adolescents with ASD. Electronic health records of adolescents (13–17 years), using mental health services in South London, with a diagnosis of ASD were analyzed. Natural language processing was employed to identify mentions of bullying and suicidality in the free text fields of adolescents' clinical records. Cox regression analysis was employed to investigate the longitudinal relationship between bullying and suicidality outcomes. Reported experience of bullying in the first month of clinical contact was associated with an increased risk suicidality over the follow‐up period (hazard ratio = 1.82; 95% confidence interval = 1.28–2.59). In addition, female gender, psychosis, affective disorder diagnoses, and higher intellectual ability were all associated with suicidality at follow‐up. This study is the first to demonstrate the strength of longitudinal associations between bullying and suicidality in a clinical population of adolescents with ASD, using automated approaches to detect key life events within clinical records. Our findings provide support for identifying and dealing with bullying in schools, and for antibullying strategy's incorporation into wider suicide prevention programs for young people with ASD. Autism Res 2020, 13: 988‐997. © 2020 The Authors. Autism Research published by International Society for Autism Research published by Wiley Periodicals, Inc. LAY SUMMARY: We investigated the relationship between bullying and suicidality in young people with autism spectrum disorder (ASD). We examined the clinical records of adolescents (aged 13–18 years old) with ASD in South London who were receiving treatment from Child and Adolescent Mental Health Services. We found that if they reported being bullied in the first month after they were first seen by mental health services, they were nearly twice as likely to go on to develop suicidal thoughts or behaviors

Cooperative Assembly of Terminase and Integration Host Factor at the Packaging Initiation Site of Bacteriophage Lambda

Thesis (Ph.D.)--University of Washington, 2013Packaging of viral genomes into procapsids by terminase enzymes is conserved in many DNA viruses. Terminases bind to linear concatemers of replicated viral genomes and concomitantly excise (mature) and package a single genome per procapsid. In this thesis, I interrogate the role of E. coli integration host factor (IHF) in mediating the site-specific assembly of bacteriophage lambda terminase at its cognate DNA site, cos, which serves as the packaging initiation site. IHF binds to an I-element within cos and introduces a strong bend in the duplex. It was previously demonstrated that the small terminase subunit could stabilize an IHF-induced bend at cos. I hypothesized that terminase holoenzyme and IHF cooperatively assemble at cos and wrap the duplex into a compact nucleoprotein complex. Rigorous analysis of this cooperative assembly is complex due to the multiple terminase and IHF binding elements within cos. Therefore, I dissected the cos site into individual specific and nonspecific IHF binding sequences, and analyzed the relevant protein affinities for these subsites as well as for (1) the full-length cos site and (2) a random nonspecific (NS) sequence of equivalent length. Analytical ultracentrifugation and electrophoretic mobility shift studies show that IHF and terminase only modestly discriminate between cos and NS-DNA substrates; however, the two proteins cooperatively bind to cos-DNA. The data suggest that IHF confers site-specificity of binding to terminase. Also evident is significant nonspecific DNA binding concurrent with specific interactions, even on specific DNA substrates. IHF likely facilitates the high-affinity cooperative assembly of a relevant nucleoprotein complex at the cos site despite significant nonspecific binding of both proteins to DNA, with the functional significance of nonspecific DNA binding being the enhancement of protein-DNA interactions. Furthermore, sedimentation equilibrium studies demonstrate that while terminase assembles in the absence of IHF as a dimer on a 274 bp DNA substrate inclusive of the entire cos site, in the presence of IHF a nucleoprotein complex of mass consistent with five terminase protomers and two IHF molecules results. This finding further implicates IHF in the cooperative assembly of a specific ternary IHF-DNA-terminase complex at the packaging initiation site of bacteriophage lambda. A terminase packaging enzyme that both (1) site-specifically matures DNA and (2) packages DNA in a sequence-independent manner must be capable of both specific and nonspecific DNA binding. This work furthers the understanding of (1) one of the factors (IHF) involved in the site-specific assembly of a nucleoprotein complex required for the initiation of viral packaging, and (2) the nature of the specific nucleoprotein complex assembled at the cos site prior to DNA maturation and packaging

Recorded poor insight as a predictor of service use outcomes:Cohort study of patients with first-episode psychosis in a large mental healthcare database

ObjectivesTo investigate recorded poor insight in relation to mental health and service use outcomes in a cohort with first-episode psychosis.DesignWe developed a natural language processing algorithm to ascertain statements of poor or diminished insight and tested this in a cohort of patients with first-episode psychosis.SettingThe clinical record text at the South London and Maudsley National Health Service Trust in the UK was used.ParticipantsWe applied the algorithm to characterise a cohort of 2026 patients with first-episode psychosis attending an early intervention service.Primary and secondary outcome measuresRecorded poor insight within 1 month of registration was investigated in relation to (1) incidence of psychiatric hospitalisation, (2) odds of legally enforced hospitalisation, (3) number of days spent as a mental health inpatient and (4) number of different antipsychotic agents prescribed; outcomes were measured over varying follow-up periods from 12 months to 60 months, adjusting for a range of sociodemographic and clinical covariates.ResultsRecorded poor insight, present in 48.9% of the sample, was positively associated with youngest and oldest age groups, unemployment and schizophrenia (compared with bipolar disorder) and was negatively associated with Asian ethnicity, married status, home ownership and recorded cannabis use. It was significantly associated with higher levels of all four outcomes over the succeeding 12 months. Associations with hospitalisation incidence and number of antipsychotics remained independently significant when measured over 60 and 48 months, respectively.ConclusionsRecorded poor insight in people with recent onset psychosis predicted higher subsequent inpatient mental healthcare use. Improving insight might benefit patients’ course of illness as well as reduce mental health service use

Investigating the relationship between thought interference, somatic passivity and outcomes in patients with psychosis:a natural language processing approach using a clinical records search platform in south London

OBJECTIVES: We aimed to apply natural language processing algorithms in routine healthcare records to identify reported somatic passivity (external control of sensations, actions and impulses) and thought interference symptoms (thought broadcasting, insertion, withdrawal), first-rank symptoms traditionally central to diagnosing schizophrenia, and determine associations with prognosis by analysing routine outcomes. DESIGN: Four algorithms were developed on deidentified mental healthcare data and applied to ascertain recorded symptoms over the 3 months following first presentation to a mental healthcare provider in a cohort of patients with a primary schizophreniform disorder (ICD-10 F20-F29) diagnosis. SETTING AND PARTICIPANTS: From the electronic health records of a large secondary mental healthcare provider in south London, 9323 patients were ascertained from 2007 to the data extraction date (25 February 2020). OUTCOMES: The primary binary dependent variable for logistic regression analyses was any negative outcome (Mental Health Act section, >2 antipsychotics prescribed, >22 days spent in crisis care) over the subsequent 2 years. RESULTS: Final adjusted models indicated significant associations of this composite outcome with baseline somatic passivity (prevalence 4.9%; adjusted OR 1.61, 95% CI 1.37 to 1.88), thought insertion (10.7%; 1.24, 95% CI 1.15 to 1.55) and thought withdrawal (4.9%; 1.36, 95% CI 1.10 to 1.69), but not independently with thought broadcast (10.3%; 1.05, 95% CI 0.91 to 1.22). CONCLUSIONS: Symptoms traditionally central to the diagnosis of schizophrenia, but under-represented in current diagnostic frameworks, were thus identified as important predictors of short-term to medium-term prognosis in schizophreniform disorders

Identifying Suicide Ideation and Suicidal Attempts in a Psychiatric Clinical Research Database using Natural Language Processing

AbstractResearch into suicide prevention has been hampered by methodological limitations such as low sample size and recall bias. Recently, Natural Language Processing (NLP) strategies have been used with Electronic Health Records to increase information extraction from free text notes as well as structured fields concerning suicidality and this allows access to much larger cohorts than previously possible. This paper presents two novel NLP approaches – a rule-based approach to classify the presence of suicide ideation and a hybrid machine learning and rule-based approach to identify suicide attempts in a psychiatric clinical database. Good performance of the two classifiers in the evaluation study suggest they can be used to accurately detect mentions of suicide ideation and attempt within free-text documents in this psychiatric database. The novelty of the two approaches lies in the malleability of each classifier if a need to refine performance, or meet alternate classification requirements arises. The algorithms can also be adapted to fit infrastructures of other clinical datasets given sufficient clinical recording practice knowledge, without dependency on medical codes or additional data extraction of known risk factors to predict suicidal behaviour.</jats:p

Association between depressive symptoms and cognitive-behavioural therapy receipt within a psychosis sample:a cross-sectional study

OBJECTIVES: To examine whether depressive symptoms predict receipt of cognitive–behavioural therapy for psychosis (CBTp) in individuals with psychosis. DESIGN: Retrospective cross-sectional analysis of electronic health records (EHRs) of a clinical cohort. SETTING: A secondary National Health Service mental healthcare service serving four boroughs of south London, UK. PARTICIPANTS: 20 078 patients diagnosed with an International Classification of Diseases, version 10 (ICD-10) code between F20 and 29 extracted from an EHR database. PRIMARY AND SECONDARY OUTCOME MEASURES: Primary: Whether recorded depressive symptoms predicted CBTp session receipt, defined as at least one session of CBTp identified from structured EHR fields supplemented by a natural language processing algorithm. Secondary: Whether age, gender, ethnicity, symptom profiles (positive, negative, manic and disorganisation symptoms), a comorbid diagnosis of depression, anxiety or bipolar disorder, general CBT receipt prior to the primary psychosis diagnosis date or type of psychosis diagnosis predicted CBTp receipt. RESULTS: Of patients with a psychotic disorder, only 8.2% received CBTp. Individuals with at least one depressive symptom recorded, depression symptom severity and 12 out of 15 of the individual depressive symptoms independently predicted CBTp receipt. Female gender, White ethnicity and presence of a comorbid affective disorder or primary schizoaffective diagnosis were independently positively associated with CBTp receipt within the whole sample and the top 25% of mentioned depressive symptoms. CONCLUSIONS: Individuals with a psychotic disorder who had recorded depressive symptoms were significantly more likely to receive CBTp sessions, aligning with CBTp guidelines of managing depressive symptoms related to a psychotic experience. However, overall receipt of CBTp is low and more common in certain demographic groups, and needs to be increased

Seasonal impact of mineral dust on deep-ocean particle flux in the eastern subtropical Atlantic Ocean

International audienceSeasonal lithogenic particle and Al fluxes were obtained from a deep-ocean sediment trap deployment during 1992 and 1993 off NW Africa, and were compared concurrently with atmospheric Al concentrations and two-dimensional backward trajectories of windfields from two barometric levels in the lower and mid troposphere. Marine Al fluxes, lithogenic particle fluxes and grain size distributions in the area were found to be directly linked to airmass pathways and surface mineral Ž y2 y1. Ž aerosol concentrations. At 1000 m water depth, highest Al fluxes 10.77 mg m day , lithogenic particle fluxes 99.25 y2 y1. Ž. mg m day and smallest mean grain sizes 11.9 mm occurred during the winter and spring season, concurrent with Ž y3. highest atmospheric dust load and Al-concentrations 15 300 ng m in the lower troposphere. A strong seasonal change of the main atmospheric dust transport from low altitude winds during winterrspring to higher altitudes during summer is Ž. Ž y2 y1. clearly reflected at depth by a significant coarsening of mean grain sizes 18.6 mm and lowest Al 0.81 mg m day and Ž y2 y1. lithogenic particle fluxes 11.3 mg m day found in the sediment traps. The comparison of marine, atmospheric and model derived data used within this study highlights the close temporal coupling between atmospheric dust transport and the deep-ocean particle stock.

Self-Assembled p–n Homojunction in SnS₂ Nanosheets for Electrocatalytic Hydrogen Evolution: The Role of Sulfur Defects

In this study, we demonstrate the impressive electrocatalytic hydrogen evolution (HER) capabilities of a self-assembled p–n homojunction in SnS2 nanosheets enriched with sulfur vacancies (VS) and tin vacancies (VSn). Our experiments demonstrate that after aqueous washing, SnS2 nanosheets washed ten times (S10) contain more VS and VSn than those washed three times (S3). As a result, S10 exhibits a significantly better HER performance than S3, with an overpotential of 119 mV at 10 mA/cm2, a Tafel slope of 140 mV/dec, a turnover frequency of 10.9 m/s, and faster H+ mass transport. S10 exhibits improved HER performance with an overpotential of 116 mV at 10 mA/cm2 and a Tafel slope of 96 mV/dec in the visible spectrum due to VS and better interfacial carrier separation from the p–n homojunction. Our partial density of states and Gibbs free energy calculation for H adsorption (ΔGH) reveal that undercoordinated Sn atoms near VS contribute to H adsorption in both S3 and S10. However, as S10 contains more VS than S3, its HER activity is superior. Our findings suggest that defect engineering through a simple and effective chemical synthesis approach can optimize the electro- and photoelectrochemical HER activity of layered two-dimensional SnS2 nanosheets