Comparative study of machine learning methods for modeling associations between risk factors and future dementia cases.

A substantial portion of dementia risk can be attributed to modifiable risk factors that can be affected by lifestyle changes. Identifying the contributors to dementia risk could prove valuable. Recently, machine learning methods have been increasingly applied to healthcare data.

Blunted Cardiovascular Reactivity Predicts Worse Performance in Working Memory Tasks.

When we experience psychological challenges in the environment, our heart rate usually rises to make us more able to solve the task, but there is an individual difference in cardiovascular reactivity (CVR). Extreme CVR to environmental demands has been associated with worse health outcomes, with blunted CVR (little or no rise in heart rate) related to maladaptive behavior, including depression. The blunted CVR has been explained by motivational disengagement, which involves giving up on a task when facing obstacles.

Exposure factors associated with dementia among older adults in Iceland: the AGES-Reykjavik study.

The study aimed to assess whether factors related to cognitive performance were associated with the development of dementia. Additionally, the study aimed to establish whether cognitive performance at baseline or change in cognition between baseline and follow-up (five-year period) had a stronger association with whether an individual would fulfill a dementia criterion at follow-up. The data was collected from 2002 to 2011.

Cognition and brain health among older adults in Iceland: the AGES-Reykjavik study.

The paper aimed to compare how factors previously identified as predictive factors for cognitive decline and dementia related to cognitive performance on the one hand and brain health on the other. To that aim, multiple linear regression was applied to the AGES-Reykjavik study epidemiological data. Additionally, a regression analysis was performed for change in cognition over 5 years, using the same exposure factors.

Case Report: Successful Implementation of Integrative Cognitive Remediation for Early Psychosis.

Many individuals demonstrate functionally relevant impairment in neurocognition as well as social cognition early on in the course of their psychotic disorder. There is robust evidence supporting cognitive remediation as an effective treatment of cognitive dysfunction in schizophrenia. Increasingly it is accepted that earlier treatment is associated with better outcome and that it is important to systematically assess and treat cognitive dysfunction before the cognitive and functional disabilities are fully realized.

P300 Analysis Using High-Density EEG to Decipher Neural Response to rTMS in Patients With Schizophrenia and Auditory Verbal Hallucinations.

Schizophrenia is a complex disorder about which much is still unknown. Potential treatments, such as transcranial magnetic stimulation (TMS), have not been exploited, in part because of the variability in behavioral response. This can be overcome with the use of response biomarkers.

Integrative cognitive remediation for early psychosis: A 12-month follow-up.

In recent years, a growing number of studies have attempted to treat social-cognitive impairment within neurocognitive remediation as means of improving outcome in psychotic disorders with promising results. However, the durability of the effects is still under debate and little is known about the long-term efficacy of integrated neuro- and social-cognitive remediation in early psychosis. The purpose of this study was to examine long-term effects of a 12-week integrative cognitive remediation (ICR) for early psychosis.

Increase in the incidence of alcoholic pancreatitis and alcoholic liver disease in Iceland: impact of alcohol consumption.

To analyze the incidence of acute alcoholic pancreatitis and of severe alcoholic liver disease (ALD) and its association with alcohol consumption with identification of both alcoholic cirrhosis (AC) and severe alcoholic hepatitis (AH), in a population-based setting. A search was undertaken in diagnoses database for diagnostic codes in order to find patients hospitalized with incident acute alcoholic pancreatitis (AP) and alcoholic liver disease in Iceland in 2001-2015. Diagnoses were verified in all patients who were retrospectively reviewed.

Trail Making Test, Stroop, and Verbal Fluency: Regression-Based Norms for the Icelandic Population.

Objective: The aim of this study was to construct regression-based norms for 3 executive-function tests: the Trail Making Test, Stroop, and Verbal Fluency.

Method: A sample of 1,034 healthy Icelandic adults (18-64 years) was used to calculate predicted scores for test measures from all 3 tests, controlled for the effects of age, gender, and education, as well as the interaction between these variables.

Results: The 3 demographic variables showed significant effects on most test measures and were included in the final equation for estimating predicted scores.

Cognitive Measures and Performance on the Antisaccade Eye Movement Task.

The antisaccade (AS) task is considered a prominent measure of inhibitory control, but it is still unclear which cognitive processes are used for successful performance of the task. Previous results have provided evidence for the involvement of several processes, including working memory (WM), inhibition and attention. Thus, the aim of this study was to explore, using a range of neuropsychological tests, which cognitive factors predict individual differences in AS performance.

Integrative cognitive remediation for early psychosis: Results from a randomized controlled trial.

Early application of cognitive remediation may help prevent the development of long-term functional impairments that characterize psychotic disorders. Interventions that encompass both neurocognitive and social-cognitive training may work synergistically to bridge the gap between cognitive gains and functional outcomes in early psychosis. We integrated three cognitive remediation approaches: Neuropsychological Educational Approach to Remediation (NEAR), Compensatory Cognitive Training (CCT), and Social Cognition and Interaction Training (SCIT), and evaluated the effects on cognition, clinical symptoms, self-assessed and informant-assessed social functioning in early psychosis.

Social and non-social measures of cognition for predicting self-reported and informant-reported functional outcomes in early psychosis.

The main aim of this study was to investigate the individual contributions of neurocognitive and social-cognitive domains to self-reported and informant-reported functional outcome in early psychosis. We also sought to further characterize the nature of cognitive impairments in this sample and explore the interrelationships between the social-cognitive measures and how they correlate with measures of neurocognition and clinical symptoms. In this study, 70 patients (mean age: 24.

Schizophrenia, cognition, and aging: cognitive deficits and the relationship between test performance and aging.

Most measures of cognitive function decline with age during adulthood. Research indicates that people with schizophrenia experience considerable cognitive deficits. These deficits appear to become more troublesome with increasing age, but this has been debated.

Risk factors for chronic and recurrent pancreatitis after first attack of acute pancreatitis.

Objective: To study the outcome of acute pancreatitis and risk factors for recurrent and chronic pancreatitis in a population based cohort of patients with first-time acute pancreatitis.

Methods: All patients with first-time acute pancreatitis from 2006-2015 in Iceland were retrospectively evaluated. Medical records were scrutinized and relevant data extracted.

Optimal designs for a multiresponse Emax model and efficient parameter estimation.

The aim of dose finding studies is sometimes to estimate parameters in a fitted model. The precision of the parameter estimates should be as high as possible. This can be obtained by increasing the number of subjects in the study, N, choosing a good and efficient estimation approach, and by designing the dose finding study in an optimal way.

Simultaneous estimation of parameters in the bivariate Emax model.

In this paper, we explore inference in multi-response, nonlinear models. By multi-response, we mean models with m > 1 response variables and accordingly m relations. Each parameter/explanatory variable may appear in one or more of the relations.

Addition of eGFR and Age Improves the Prognostic Absolute Renal Risk-Model in 1,134 Norwegian Patients with IgA Nephropathy.

Background: Predicting outcome in individual patients with IgA nephropathy (IgAN) is difficult but important. For this purpose, the absolute renal risk (ARR) model has been developed in a French cohort to calculate the risk of end-stage renal disease (ESRD) and death. ARR (0-3) is scored in individual IgAN patients based on the presence of proteinuria ≥1 g/24 h, hypertension, and severe histopathological lesions (1 point per risk factor).

CNVs conferring risk of autism or schizophrenia affect cognition in controls.

In a small fraction of patients with schizophrenia or autism, alleles of copy-number variants (CNVs) in their genomes are probably the strongest factors contributing to the pathogenesis of the disease. These CNVs may provide an entry point for investigations into the mechanisms of brain function and dysfunction alike. They are not fully penetrant and offer an opportunity to study their effects separate from that of manifest disease.

Analysing the large decline in coronary heart disease mortality in the Icelandic population aged 25-74 between the years 1981 and 2006.

Background: Coronary heart disease (CHD) mortality rates have been decreasing in Iceland since the 1980s. We examined how much of the decrease between 1981 and 2006 could be attributed to medical and surgical treatments and how much to changes in cardiovascular risk factors.

Methodology: The previously validated IMPACT CHD mortality model was applied to the Icelandic population.

COMT val(158)met genotype and smooth pursuit eye movements in schizophrenia.

The association between the catechol-O-methyltransferase (COMT) val(158)met polymorphism (rs4680) and smooth pursuit eye movements (SPEM) was investigated in 110 schizophrenia patients and 96 controls. Patients had lower steady-state pursuit gain and made more frequent saccades than controls. Genotype was not associated with schizophrenia or SPEM, in either group or the combined sample.

Neuregulin-1 genotypes and eye movements in schizophrenia.

Neuregulin-1 (NRG-1) is a putative susceptibility gene for schizophrenia but the neurocognitive processes that may involve NRG-1 in schizophrenia are unknown. Deficits in antisaccade (AS) and smooth pursuit eye movements (SPEM) are promising endophenotypes, which may be associated with brain dysfunctions underlying the pathophysiology of schizophrenia. The aim of this study was to investigate the associations of NRG-1 genotypes with AS and SPEM in schizophrenia patients and healthy controls.

Common variants conferring risk of schizophrenia.

Schizophrenia is a complex disorder, caused by both genetic and environmental factors and their interactions. Research on pathogenesis has traditionally focused on neurotransmitter systems in the brain, particularly those involving dopamine. Schizophrenia has been considered a separate disease for over a century, but in the absence of clear biological markers, diagnosis has historically been based on signs and symptoms.

Large recurrent microdeletions associated with schizophrenia.

Reduced fecundity, associated with severe mental disorders, places negative selection pressure on risk alleles and may explain, in part, why common variants have not been found that confer risk of disorders such as autism, schizophrenia and mental retardation. Thus, rare variants may account for a larger fraction of the overall genetic risk than previously assumed. In contrast to rare single nucleotide mutations, rare copy number variations (CNVs) can be detected using genome-wide single nucleotide polymorphism arrays.