This thesis pertains to the uses of Functional Data Analysis and Machine Learning when analyzing high-dimensional structured datasets. The theme that motivates the first two chapters is the development of dimension-reduction methods in the context of functional data to advance the understanding of in-vivo measurements of neural-spike data. The last chapter addresses the analysis of survey data using machine learning techniques to identify novel risk factors for suicide in the general population. The first chapter of this thesis, "Adaptive Functional Principal Component Analysis," provides a novel method for adequately capturing modes of variation in data exhibiting sharp changes in smoothness. Our work integrates a novel scatterplot technique that adaptively smooths latent functions estimated in an FPCA framework. We are motivated to identify coordinated patterns of brain activity across multiple simultaneously-recorded neurons during motor behavior to understand the dynamics between the brain and dexterous movement. Our proposed method adequately captures the underlying biological mechanisms in our experiment, offering interpretable activation patterns when compared to standard approaches. The second chapter of our dissertation develops statistical procedures to compare the eigendecomposition from two samples of functional data. We first introduce appropriate tests for both independent and paired functions. We are motivated to test whether activation patterns in the motor cortex hold constant when a mouse performs a reaching movement repeatedly. We test all pairwise comparisons across trials and compare the distribution of the p-values against the distribution under the null. Our results suggest trial-to-trial variation in the latent activation patterns that can't be attributed to sampling noise. Our results can inform future methodology for deriving activation patterns from noisy neural spikes. The last chapter of this dissertation dives into applying Machine Learning Techniques to analyze survey data. We use the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) survey to identify novel risk factors for suicide attempts in the general population. Our analysis uses a Balanced Random Forest (BRF) approach and incorporates extreme class imbalance and survey architecture into the algorithm. We extend prior research focusing on high-risk clinical samples by identifying risk factors for suicide attempts in the general population. Our work identifies risk variables that can help guide clinical assessment and the development of suicide risk scales.

Bakgrund: Suicid är ett folkhälsoproblem som har nått epidemiska mått globalt. Suicidala tankar kan kopplas till känslor av hopplöshet och ambivalens, ensamhet, brist på självvärde och otillräcklig förmåga att hantera sitt liv. Specialistsjuksköterskan utför suicidriskbedömningar för att förebygga och förhindra suicid i den psykiatriska öppenvården. Utförandet av suicidriskbedömningar är en komplex uppgift för specialistsjuksköterskan och det är viktigt att det finns möjlighet att kunna reglera känslor och balansera engagemang. Syfte: Syftet med studien var att beskriva specialistsjuksköterskors erfarenheter av att genomföra suicidriskbedömningar i psykiatrisk öppenvård. Metod: Induktiv ansats användes och materialet analyserades med kvalitativ innehållsanalys. Specialistsjuksköterskor inom vuxenpsykiatrisk öppenvård i Region Skåne intervjuades. Tio semistrukturerade intervjuer genomfördes. Resultat: I resultatet framkom tre kategorier: betydelsen av tillit till egen intuition, vikten av tilltro till organisationens stödjande struktur och värdet av förtroende i kommunikationen med patienten. Slutsats: Genom att ha insikt om vad arbetets utmaningar innebär för specialistsjuksköterskan, genom lyhördhet, god kommunikation, fungerande rutiner och kollegial samverkan optimeras förutsättningarna för att utföra en trygg suicidriskbedömning.Resultatet kan användas i utbildningssyfte och som diskussionsunderlag i klinisk verksamhet för att öka kunskap, kompetens och självmedvetenhet vid suicidriskbedömningar. Vidare forskning om suicidpreventivt arbeteutifrån patientens perspektiv skulle vara till nytta. / Background: Suicide is a public health problem that has reached epidemic proportions globally. Suicidal thoughts can be linked to feelings of hopelessness and ambivalence, loneliness, lack of self-worth, and insufficient ability to manage one's life. The specialist nurse performs suicide risk assessments to prevent suicide in psychiatric outpatient care.Carrying out suicide risk assessments is a complex task for the specialist nurse, and it is important that there is an opportunity to regulate emotions and balance commitment. Aim: The aim of the study was to describe specialist nurses' experiences of carrying out suicide risk assessments in psychiatric outpatient care. Method: An inductive approach was used, and the material was analyzed with qualitative content analysis. Specialist nurses in adult psychiatric outpatient care in Region Skåne were interviewed. Ten semi-structured interviews were conducted. Results: The results revealed three categories: The importance of trust in one's own intuition, The importance of trust in the supportive structure of the organization and the Value of trust in communication with the patient.Conclusion: By having insight into what the challenges of the work mean for the specialist nurse, through responsiveness and good communication, functioning routines and collegial collaboration, the conditions for performing a suicide risk assessment safely are optimized. The result can be used for educational purposes and as a basis for discussion in clinical practice to increase knowledge, competence and self-awareness in suicide risk assessments. Further research on suicide risk prevention from the patient´s perspective would be beneficial.

Wu Chi Hang. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 41-49). / Abstracts in English and Chinese. / List of Figures --- p.i / List of Tables --- p.ii / Chapter Chapter 1: --- Introduction to the Study --- p.1 / Introduction --- p.1 / The Role of Family Problems --- p.3 / The Mediating Effect of Self-Perception --- p.5 / The Mediating Effect of Beliefs about the World --- p.7 / Combining Self-Perceptions and Social Beliefs as Mediators --- p.11 / Gender Difference in the Mediation Model Interactions --- p.11 / Chapter Chapter 2: --- Method --- p.13 / Sample and Procedures --- p.13 / Instruments --- p.13 / McMaster Family Assessment Device (FAD) --- p.13 / Perceived Stress Scale (PSS) --- p.14 / Depression-Cognition: Cognition Checklist ´ؤ Depression (CCL-D) --- p.14 / Rosenberg Self-Esteem Scale --- p.14 / The Social Axioms Survey --- p.14 / Suicidal Ideation Questionnaire (SIQ) --- p.15 / Analysis --- p.16 / Chapter Chapter 3: --- Results --- p.17 / Correlation among Variables --- p.17 / Exploratory Factor Analysis of FAD and Self-Perceptions --- p.18 / Mediation Analysis for Suicidal Ideation --- p.20 / Model Containing both Mediators --- p.24 / Testing Gender Differences in the Model --- p.28 / Chapter Chapter 4: --- Discussion --- p.31 / Family and Suicidal Ideation --- p.31 / Family as a System --- p.32 / The Role of Social Beliefs --- p.34 / A Gender-General Model for Suicidal Ideation --- p.37 / Implications and Further Research --- p.38 / References --- p.40 / Appendix --- p.49

Background Self-harm is a major and growing public health issue among young people worldwide. Self-harm is an important risk factor for suicide, which is one of the leading causes of death for young people. Although suicide rates are declining overall, this trend is not seen in young people. Young people with mental distress and/or suicidal thoughts are reluctant to seek help, and often drop out of treatment initiated after a self-harm episode. Many young people who self-harm have had contact with healthcare before their first self-harm episode, but often for reasons other than suicidal thoughts or psychiatric problems. In this context, physical illness is associated with increased risk for self-harm and suicide among young people. The present thesis investigated how young people perceived the help and support they received before and after an episode of self-harm. A further aim was to map the inpatient somatic healthcare contacts young patients had before an episode of self-harm, and determine any relationship to risk for self-harm and suicide. Method Four studies were conducted using qualitative and quantitative methods. Participants were people aged 16-24 years. The definition of self-harm was based on the intentional self-harm criteria in the International Classification of Diseases, tenth revision, which includes all forms of self-harm without ascribing suicidal intent. In the first two studies, 10 respective 9 participants with a first healthcare contact for self-harm were interviewed during 2009-2011. The interviews covered participants’ knowledge and experience of professional care before their healthcare contact for self-harm. Participants were interviewed a second time 6 months later about their experiences with professional care during the period since their initial interview. Qualitative content analysis was used for all interviews. For the next two studies, we selected 16,235 participants with a first hospitalisation for self-harm during 1999-2009 from the Swedish National Inpatient Register. These cases were compared with matched controls to determine the odds of having been admitted with a non-psychiatric diagnosis during the year preceding the self-harm admission. To assess risk for suicide, data were retrieved from the Swedish Cause of Death Register for all deceased participants until 2013, and group differences were determined using survival analysis. Results In the first interview, participants described how they wanted more information on where they could turn for professional help. They also wanted different help-seeking pathways and emphasised the importance of the quality of professional contact. After 6 months, participants stressed the importance of being able to rely on professionals and treatment. Their life circumstances significantly affected their treatment, and practical help was appreciated. The register studies showed that young people admitted for self-harm were more likely to have been hospitalised with symptomatic diagnoses such as abdominal pain and syncope/collapse, and somatic illnesses such as epilepsy and diabetes mellitus type 1. A higher proportion of cases (4.5%; women 2.6%, men 8.8%) died during the study period than controls (0.3%; women 0.2%, men 0.6%) (p<0.001). For both cases and controls, a higher proportion of those with a previous somatic admission died from suicide during the study period than those without a somatic admission (cases: 4.2% vs. 2.8%, p<0.05). For cases with a somatic admission, the hazard ratio was 1.43 (95% confidence interval 1.04-1.98) compared with those without somatic admissions (controlled for age, sex and psychiatric admission). Survival of cases with a previous somatic admission compared with those without was 98.4% versus 99.2% after the first year, 97.8% versus 98.9% after the second year, and 95.5% versus 96.9% after the tenth year. Conclusion These findings suggest that healthcare providers need to find new ways to reach young people at risk for suicidal behaviour. Access to professional help should be easy and direct. Treatment for young people after self-harm should be flexible, and be receptive to input from the patient. The importance of and need for basic practical help should not be overlooked. Somatic healthcare contact provides an opportunity for intervention, particularly as psychiatric problems can manifest as physical symptoms, and physical illness is a risk factor for self-harm and suicide.

Psychologists and other mental health professionals working in correctional institutions bear the considerable responsibility for identifying, diagnosing, and treating mentally disordered inmates. The importance of these responsibilities has been recognized in recent years because of the burgeoning population of inmates in general and the higher numbers of inmates with mental illness in particular. Research has demonstrated that the screens currently used in correctional settings to identify mentally disordered and suicidal inmates are either unvalidated or generally ineffective. This study investigates the validity of different mental health screens in a jail population. Inmates from the Grayson County Jail were administered three screens: the Referral Decision Scale (RDS), Personality Assessment Screener (PAS), and the Mental Disability/Suicide Intake Screen (MDSIS). Criterion measures were the Schedule for Affective Disorders and Schizophrenia (SADS) for Axis I disorders and the Suicide Probability Scale (SPS) for suicidal ideation. Results indicate that each screen most effectively assessed one clinical domain: the RDS for psychosis, the MDSIS for suicidality, and the PAS for depression. Gender differences were observed in screen items most effective for classifying inmates by suicide risk level.

Made available in DSpace on 2016-03-22T17:27:35Z (GMT). No. of bitstreams: 1 xenia1.pdf: 708937 bytes, checksum: cc885d49bb2a8c9ada32a3218f9e37f3 (MD5) Previous issue date: 2014-01-24 / Objective: To investigate the relationship between peripheral levels of corticotropin releasing hormone (CRH) and interleukin-1 (IL-1) in BD individuals with and without suicide risk (SR) and controls. Methods: 120 young adults (40 controls, 40 BD subjects without SR and 40 BD subjects with SR) were enrolled from a population-based study carried out in the city of Pelotas, (Brazil). BD and SR were assessed with MINI 5.0 and peripheral markers were evaluated by ELISA. Results: Levels of CRH were significantly lower both in BD subjects without SR (p = 0.04) or with SR (p = 0.02) when compared to control. However, levels of IL-1 were increased in BD subjects with SR (p = 0.05) when compared to control. Socio-demographic and clinical variables, current mood episode and use of psychiatry medication were not associated with changes in these markers. No correlation was found between peripheral levels of CRH and IL-1 (p = 0.60) in the population or in BD with SR group (p = 0.88) Conclusions: These results suggest that peripheral mechanisms linking stress hormones and the immune system might be critical patterns involved in suicidal behavior associated with BD / Avaliar se existem alterações nos níveis periféricos do hormônio liberador de corticotropina (CRH) e na interleucina-1 (IL-1) em pacientes com transtorno bipolar, com ou sem risco de suicídio comparando com indivíduos sem transtornos de humor. 2.3.2. Objetivos específicos 1. Avaliar os níveis séricos de CRH e IL-1 em pacientes com diagnóstico de transtorno bipolar comparando com controles sem transtornos de humor; 2. Comparar os níveis séricos de CRH e IL-1 em pacientes com diagnóstico de transtorno bipolar com e sem risco de suicídio, e controles sem transtornos de humor; 3. Investigar se existe algum efeito da diferença de gênero, idade, atividade física, índice de massa corporal e fatores sócio- demográficos com os níveis de CRH e IL-1 em pacientes bipolares com e sem risco de suicídio e controles. 4. Verificar se existem alterações nos níveis periféricos de CRH e IL-1 durante os episódios atuais de humor dentro do transtorno bipolar. 5. Verificar se existem uma correlação entre os níveis periféricos de CRH e IL-1

Made available in DSpace on 2016-03-22T17:27:35Z (GMT). No. of bitstreams: 1 SharonMFerreir.pdf: 2163870 bytes, checksum: d5e466194ea4c397ec8640eb900fa160 (MD5) Previous issue date: 2014-10-27 / % Major depressive disorder (MDD) is one of the most prevalent psychiatric disorders that affect approximately 17% of the population in a lifetime. Neurotrophins (NGF) are a group of structurally related proteins, which control the development and differentiation of nerve cells that play a role in cellular migration proliferation, differentiation and phenotypic maintenance central nervous system development. Thus, the role of NGF in neuronal plasticity and support, may suggests that these NGF plays an important action in the etiology and pathophysiology of suicide individuals. Therefore, the aim of this study was to evaluate serum levels of NGF in healthy and depressed person with and without suicide risk in a population-based sample of individuals. This study was performed 47 individuals with current depressive episode and suicide risk without a history of mania, and allocated to major depression and suicide risk groups. Two groups of 47 individuals each, were matched by sex and age: the active control group was composed of those with current depressive episode without risk of suicide; while the population control group included individuals with no history of affective disorder.This study was conducted by a questionnaire with demographic questions (gender, ethnicity, age and education level). After the diagnostic interview, a collection of blood from each individual was performed. Measurement of serum levels of NGF by ELISA. The comparison between the levels of NGF with the group of depressed individuals at risk for suicide without a depressed suicide risk and healthy control was performed by ANOVA with Bonferroni through post-hoc test.. NGF levels were significantly lower (p <0.001) in the groups with major depression and major depression with suicide risk (92.39 ± 41.21ng / mL and 100.99 ± 35.08ng / mL, 40 respectively) compared to the control group (149.81 ± 65.94 ng / ml). In conclusion, our study demonstrates that reducing the levels of NGF can be used as a marker TDM, compared with healthy individuals / O transtorno depressivo maior (TDM) é um dos distúrbios psiquiátricos de maior prevalência que acomete em aproximadamente 17% da população geral ao longo da vida. As neurotrofinas, dentre elas o fator de crescimento neural (NGF), são um grupo de proteínas relacionadas estruturalmente, as quais controlam o desenvolvimento e a diferenciação das células nervosas que desempenham um papel importante na proliferação celular, migração, diferenciação fenotípica e manutenção do sistema nervoso central em desenvolvimento. Devido ao importante papel das NGF na plasticidade e suporte neuronal, sugere-se que o NGF desempenha um importante papel na etiologia e fisiopatologia do suicídio. Portanto o objetivo deste estudo foi avaliar os níveis séricos de NGF em indivíduos saudáveis e deprimidos com e sem risco de suicídio de uma amostra de base populacional. O estudo envolveu 47 indivíduos para compor o grupo com depressão maior e risco de suicídio. Outros dois grupos, de 47 indivíduos cada, foram pareados por sexo e idade: o grupo controle ativo foi composto por aqueles que apresentaram episódio depressivo atual, sem risco de suicídio; enquanto o grupo controle populacional contemplou os indivíduos sem história de transtorno afetivo. O estudo foi realizado por um questionário com questões sociodemográficas (sexo, etnia, idade e escolaridade). Os níveis séricos de NGF foram analisados através da técnica de ELISA. A comparação entre os níveis de NGF com o grupo de indivíduos deprimidos com risco de suicídio, deprimidos sem risco de suicídio e controle populacional foi realizada por ANOVA, com post-hoc através do teste Bonferroni. Os níveis de NGF foram significativamente menores (p<0.001) nos grupos com depressão maior e depressão maior com risco de suicídio 38 (92.39±41.21ng/mL e 100.99±35.08ng/mL, respectivamente) quando comparados ao grupo controle (149.81±65.94ng/mL).Concluimos que a redução dos níveis de NGF podem ser utilizados como um marcador de estado em TDM, em comparação com os de indivíduos saudáveis

Introduction: Over 800,000 people die by suicide each year, and despite being a global public health issue, limited research exists exploring suicide risk assessment practices in emergency departments. The current thesis investigated emergency department suicide risk assessment practices and clinician experiences in Scotland, to develop guidance to inform the development of a clinically meaningful and feasible suicide risk assessment for these settings which is theoretically underpinned. Methods: A mixed-method triangulation approach was utilised. Two systematic reviews were conducted to update the risk and protective factor literature. This was followed by a national survey of suicide risk assessment practices in emergency departments. Fifty-one clinicians across 17 emergency departments participated, and six clinicians participated in follow-up semi-structured interviews to investigate their experiences, which were analysed using thematic analysis. Findings of the thesis were triangulated using the ‘following-a-thread' method, to develop guidance for informing the development of future risk assessment for use in emergency departments. Results: The systematic reviews identified emerging risk and protective factors including, sexual orientation and internet usage. The survey identified substantial variation in practice between emergency department clinicians. Only 35 (68.6%) participants reported using a suicide risk assessment tool. Importantly, variation was found not only across clinicians and departments, but also within departments, with clinicians based within the same department reporting differing risk assessment practices, indicating both inter- and intra-department suicide risk assessment practice differences. The qualitative analysis of clinician experience established four major themes (current experiences; components of suicide risk assessment; clinical decision-making; suicide risk assessment needs). Triangulation of findings developed recommendations for suicide risk assessment tools and training for emergency departments. Discussion: The risk and protective factor literature has evolved due to societal changes, and there is substantial variation in suicide risk assessment practices, both across and within emergency departments. Clinicians also find suicide risk assessment challenging. There is a need for consistent training, appropriate and helpful guidelines, and the improvement of risk assessment tools to improve practice. It is recommended that suicide risk assessment tools are developed to align to clinicians' needs, while taking into account research from the health domain and from related psychological research domains.

An integrative model involving optimism/pessimism and future orientation as predictors of suicide risk (viz., depressive symptoms and suicidal behavior) was tested in a sample of adult, primary care patients. Beyond the additive influence of the two predictors of suicide risk, optimism/pessimism and future orientation were also hypothesized to interact together to exacerbate suicide risk. Results indicated that optimism/pessimism was a robust predictor of suicide risk in adults. Future orientation was found to add significant incremental validity to the prediction of depressive symptoms, but not of suicidal behavior. Noteworthy, the optimism/pessimism × future orientation interaction was found to significantly augment the prediction of both depressive symptoms and suicidal behavior. Implications for therapeutic enhancement of future-oriented constructs in the treatment of suicidal individuals are discussed.

Prior research has established that a history of post-traumatic stress disorder (PTSD) and/or traumatic brain injury (TBI) increases the risk of suicide behavior. Few studies have examined the role of specific PTSD symptom clusters and suicide attempts. The current study is among a handful of studies that have examined the association between the presence of PTSD symptom clusters and suicide attempts among Veterans with PTSD and/or TBI. The study utilized archival data from a sample of 137 Veterans receiving mental health treatment at the Denver Veteran Affairs Medical Center. Results from logistic regression analyses indicated that PTSD symptom clusters were not associated with an increased risk for suicide behavior among individuals with and without a history of TBI. Results suggest that looking at the presence of PTSD symptoms is not sufficient to account for the risk of suicide behavior. Clinical and research implications on the need to examine the role of PTSD symptom severity and suicide behavior are discussed.