Publications by authors named "Marc Molendijk"

Objective: The number of forced migrants has been rising for years. Many forced migrants suffer from post-traumatic stress disorder (PTSD), depression, and/or anxiety and need treatment. Here, we evaluate the effectiveness of psychological interventions (CBT, EMDR, expressive/art, mindfulness, mixed elements, NET and psychoeducation) in reducing symptoms of PTSD, depression, and anxiety in forced migrants.

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Aims: It has been suggested that people with mental disorders have an elevated risk to acquire severe acute respiratory syndrome coronavirus 2 and to be disproportionally affected by coronavirus disease 19 (COVID-19) once infected. We aimed to analyse the COVID-19 infection rate, course and outcome, including mortality and long COVID, in people with anxiety, depressive, neurodevelopmental, schizophrenia spectrum and substance use disorders relative to control subjects without these disorders.

Methods: This study constitutes a preregistered systematic review and random-effects frequentist and Bayesian meta-analyses.

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Background: People with neurodegenerative disease and mild cognitive impairment (MCI) may have an elevated risk of acquiring severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and may be disproportionally affected by coronavirus disease 2019 (COVID-19) once infected.

Aims: To review all eligible studies and quantify the strength of associations between various pre-existing neurodegenerative disorders and both SARS-CoV-2 susceptibility and COVID-19 illness course and outcome.

Method: Pre-registered systematic review with frequentist and Bayesian meta-analyses.

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Purpose: The COVID-19 pandemic has been a leading cause of stress and feelings of loss of control, both of which have been related to eating disorder (ED) pathology onset and deterioration. We aim to estimate the magnitude of changes in the prevalence rates of, and indicators for, ED psychopathology in the face of the COVID-19 pandemic.

Method: Pre-registered systematic review with frequentist and Bayesian meta-analyses.

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Worldwide, an increase in cases and severity of domestic violence (DV) has been reported as a result of social distancing measures implemented to decrease the spreading of the Coronavirus Disease (COVID-19). As one's language can provide insight in one's mental health, this pre-registered study analyzed word use in a DV online support group, aiming to investigate the impact of the COVID-19 pandemic on DV victims in an ex post facto research design. Words reflecting social support and leisure activities were investigated as protective factors against linguistic indicators of depression in 5,856 posts from the r/domesticviolence subreddit and two neutral comparison subreddits (r/changemyview & r/femalefashionadvice).

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Background: The incubus phenomenon is a paroxysmal sleep-related disorder characterized by the visuotactile sensation of a person or entity exerting pressure on one's thorax during episodes of sleep paralysis and (apparent) wakefulness. This terrifying phenomenon is relatively unknown even though a previous meta-analysis indicated a lifetime prevalence of 0.11 for individuals in the general population and of 0.

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Article Synopsis
  • The "forced swim test" (FST) is often misrepresented as a rodent model of depression, but it's more accurately a predictor of antidepressant effects, with 60% of 600 annual studies incorrectly labeling it as indicating depression-like behavior.
  • Editors of top journals emphasize relying on peer reviews for labeling immobility in rodents while acknowledging a shift towards using animal models for neurobiological research instead of strict representations of mental disorders.
  • Current research is focusing on two key areas: the impact of glucocorticoids on mental processes (bottom-up) and advances in understanding how the brain switches between active and passive coping mechanisms (top-down), aiming to uncover links between stress adaptation and mental health issues.
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Background: The recommendations of experts who write review articles are a critical determinant of the adaptation of new treatments by clinicians. Several types of reviews exist (narrative, systematic, meta-analytic), and some of these are more vulnerable to researcher bias than others. Recently, the interest in nutritional interventions in psychiatry has increased and many experts, who are often active researchers on this topic, have come to strong conclusions about the benefits of a healthy diet on depression.

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Background: The number of refugees is at its highest since the Second World War and on the rise. Many refugees suffer from anxiety, depression and post-traumatic stress disorder (PTSD), but exact and up-to-date prevalence estimates are not available.

Aims: To report the pooled prevalence of anxiety and mood disorders and PTSD in general refugee populations residing in high-income countries and to detect sources of heterogeneity therein.

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Article Synopsis
  • This study uses a meta-analytic approach to evaluate how selective mutism (SM) is classified as an anxiety disorder in the DSM-5, combining data from 22 studies with 837 children.
  • Findings show that 80% of children with SM also have another anxiety disorder, primarily social phobia (69%), indicating that SM and anxiety disorders may not be separate conditions.
  • The study highlights a need for better research methods to assess anxiety in relation to SM, as current categorizations do not clarify the connection between the two.
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The forced swim test (FST) for rodents does not model despair or helplessness. It also is not a read-out for depression, anxiety, psychomotor retardation or autism, because these are anthropomorphic interpretations of the rodent's acquired immobility. Rather, the transition from swimming to immobility allows to examine the mechanistic underpinning of coping with inescapable stressors.

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The SMILES trial showed substantial improvement of depressive symptoms following seven consultations on healthy dieting. The very large effect size on depression reduction seems remarkable and we suggest that selectively induced expectancy and a loss of blinding have contributed to the observed effect.

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Background: Magnesium (Mg2+) has received considerable attention with regards to its potential role in the pathophysiology of the mood disorders, but the available evidence seems inconclusive.AimsTo review and quantitatively summarise the human literature on Mg2+ intake and Mg2+ blood levels in the mood disorders and the effects of Mg2+ supplements on mood.

Method: Systematic review and meta-analyses.

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Background: The incubus phenomenon is a paroxysmal sleep-related disorder characterized by compound hallucinations experienced during brief phases of (apparent) wakefulness. The condition has an almost stereotypical presentation, characterized by a hallucinated being that exerts pressure on the thorax, meanwhile carrying out aggressive and/or sexual acts. It tends to be accompanied by sleep paralysis, anxiety, vegetative symptoms, and feelings of suffocation.

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Background: It has been claimed that the quality of a diet is associated with the incidence of depressive disorders. We sought to investigate the evidence for this claim.

Methods: Systematic searches were performed up to March 6th, 2017 in order to identify prospective cohort studies that reported on exposure to dietary patterns or food groups and the incidence of depression/depressive symptoms.

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Chronotypes have been associated with psychopathology. The eveningness chronotype has been consistently linked with depressed states or depressive disorder, but the underlying mechanism remains unclear. Prior studies have shown associations between chronotype and personality traits that are linked to depression (e.

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Background: The oxytocin receptor (OXTR) gene may be involved in resilience or vulnerability towards stress, and hence in the development of stress-related disorders. There are indications that OXTR single nucleotide polymorphisms (SNPs) interact with early life stressors in predicting levels of depression and anxiety. To replicate and extend these findings, we examined whether three literature-based OXTR SNPs (rs2254298, rs53576, rs2268498) interact with childhood maltreatment in the development of clinically diagnosed depression and anxiety disorders.

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Background: Inflammatory processes and neural-immune interactions have been implicated in the pathogenesis of psychiatric conditions, but studies in bipolar disorder are inconclusive so far. We aimed to investigate whether peripheral concentrations of C-reactive protein (CRP), an acute-phase response protein of inflammatory activity, are increased in bipolar disorder across the mood spectrum.

Methods: In this systematic review and meta-analysis, we searched MEDLINE, the Cochrane Library, Scopus, and Web of Knowledge from database inception to Aug 14, 2016, for studies that measured serum and plasma CRP concentrations in adult patients with bipolar disorder (as defined by DSM-IV-TR) and healthy controls.

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An increasing number of studies suggest possible beneficial effects of exercise in alleviating ADHD functional outcomes. The current study provides a quantitative meta-analysis of the available studies investigating this relationship. Studies reporting on the effects of physical exercise on motor skills and executive functions in children with ADHD were identified through Cochrane, PsycInfo, PubMed, Web of Science databases.

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Background: The neurotrophic hypothesis postulates that mood disorders such as bipolar disorder (BD) are associated with a lower expression of brain-derived neurotrophic factor (BDNF). However, its role in peripheral blood as a biomarker of disease activity and of stage for BD, transcending pathophysiology, is still disputed. In the last few years an increasing number of clinical studies assessing BDNF in serum and plasma have been published.

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The forced swim test is based on the progressive immobility a rodent displays when immersed in a beaker filled with water from where no escape is possible. While the test was originally designed to identify the antidepressant potential of drugs, over the past decade a rapidly growing number of publications (more than 2000) portray this immobility response anthropomorphically as a measure for depression and despair. This is incorrect.

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