The acquired immobility response during the "forced swim test (FST)" is not a rodent model of depression, but the test has some validity in predicting a compound's antidepressant potential.... Show moreThe acquired immobility response during the "forced swim test (FST)" is not a rodent model of depression, but the test has some validity in predicting a compound's antidepressant potential. Nevertheless, 60% of the about 600 papers that were published annually the past 2 years label the rodent's immobility response as depression-like behaviour, but the relative contribution per country is changing. When the Editors-in-Chief of 5 journals publishing most FST papers were asked for their point of view on labelling immobility as depression-like behaviour and despair, they responded that they primarily rely on the reviewers regarding scientific merit of the submission. One Editor informs authors of the recent NIMH notice () which encourages investigators to use animal models "for" addressing neurobiological questions rather than as model "of" specific mental disorders. The neurobiological questions raised by use of the FST fall in two categories. First, research on the role of endocrine and metabolic factors, with roots in the 1980s, and with focus on the bottom-up action of glucocorticoids on circuits processing salient information, executive control and memory consolidation. Second, recent findings using novel technological and computational advances that have allowed great progress in charting top-down control in the switch from active to passive coping with the inescapable stressor executed by neuronal ensembles of the medial prefrontal cortex via the peri-aquaductal grey. It is expected that combining neural top-down and endocrine bottom-up approaches will provide new insights in the role of stress-coping and adaptation in pathogenesis of mental disorders. Show less
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... Show moreBackground: 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.AimsTo 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. Method: Systematic review with meta-analyses and meta-regression. Results: Systematic searches (final search date 3 August 2019) yielded 66 eligible publications that reported 150 prevalence estimates (total sample N = 14 882). Prevalence rates were 13 and 42% (95% CI 8-52%) for diagnosed and self-reported anxiety, 30 and 40% (95% CI 23-48%) for diagnosed and self-reported depression, and 29 and 37% (95% CI 22-45%) for diagnosed and self-reported PTSD. These estimates are substantially higher relative to tiose reported in non-refugee populations over the globe and to populations living in conflict or war settings, both for child/ adolescent and adult refugees. Estimates were similar over different home and resettlement areas and independent of length of residence. Conclusions: Our data indicate a challenging and persisting disease burden in refugees due to anxiety, mood disorders and PTSD. Knowing this is relevant for the development of public health policies of host countries. Scalable interventions, tailored for refugees, should become more readily available. Show less
Hoeboer, C.M.; Kleine, R.A. de; Molendijk, M.L.; Schoorl, S.M.D.; Oprel, D.A.C.; Mouthaan, J.; ... ; Minnen, A. van 2020
Background Many patients with post-traumatic stress disorder (PTSD) experience dissociative symptoms. The question of whether these dissociative symptoms negatively influence the effectiveness of... Show moreBackground Many patients with post-traumatic stress disorder (PTSD) experience dissociative symptoms. The question of whether these dissociative symptoms negatively influence the effectiveness of psychotherapy for PTSD is unresolved. Aims To determine the influence of dissociative symptoms on psychotherapy outcome in PTSD. Method We conducted a systematic search in Cochrane, Embase, PILOTS, PsycINFO, PubMed and Web of Science for relevant clinical trials. A random-effects meta-analysis examined the impact of dissociation on psychotherapy outcome in PTSD (pre-registered at Prospero CRD42018086575). Results Twenty-one trials (of which nine were randomised controlled trials) with 1714 patients were included. Pre-treatment dissociation was not related to treatment effectiveness in patients with PTSD (Pearson's correlation coefficient 0.04, 95% CI -0.04 to 0.13). Between-study heterogeneity was high but was not explained by moderators such as trauma focus of the psychotherapy or risk of bias score. There was no indication for publication bias. Conclusions We found no evidence that dissociation moderates the effectiveness of psychotherapy for PTSD. The quality of some of the included studies was relatively low, emphasising the need for high-quality clinical trials in patients with PTSD. The results suggest that pre-treatment dissociation does not determine psychotherapy outcome in PTSD. Show less
This study evaluates the current conceptualization of selective mutism (SM) as an anxiety disorder in the DSM-5 using a meta-analytic approach. In the absence of any systematic assessment of... Show moreThis study evaluates the current conceptualization of selective mutism (SM) as an anxiety disorder in the DSM-5 using a meta-analytic approach. In the absence of any systematic assessment of anxiety in the field of SM, we pooled prevalence data of comorbid anxiety disorders in a random-effects meta-analysis. On the basis of 22 eligible studies (N = 837), we found that 80% of the children with SM were diagnosed with an additional anxiety disorder, notably social phobia (69%). However, considerable heterogeneity was present, which remained unexplained by a priori specified moderators. The finding that SM is often diagnosed in combination with anxiety disorders, indicates that these disorders are not discrete, separable categories. Moreover, this finding does not help to elucidate the relation between SM and anxiety as an etiological mechanism or symptomatic feature. Broadening our research strategies regarding the assessment of anxiety is paramount to clarify the role of anxiety in SM, and allow for proper classification. Show less
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... Show moreThe 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. However, in a recent detailed analysis of the FST application over the past 40 years, we noted a dramatic surge in the use of this test to phenotype animals as 'depressed'. As a follow up to that report, we now present an analysis of the use of the FST over the past three years. This literature analysis shows that the popularity of the EST is still increasing and that the majority of researchers qualifies the rodent's floating response as depressive-like behavior. However, over the past few years we also note a trend to interpret immobility rather as the expression of a coping strategy. In view of this result, we have sent a poll to the relevant authors to learn how consistent they are in naming FST behavior. Remarkably, we find a dramatic inverse correlation between their first qualification of acquired immobility as depressive-like behavior towards their current interpretation as coping strategy. In this contribution we have embedded our literature analysis and poll results in an update on the management of coping with inescapable stressors by processing in prefrontal cortical circuitry and glucocorticoid feedback. Show less
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... Show moreThe 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. However, in a recent detailed analysis of the FST application over the past 40 years, we noted a dramatic surge in the use of this test to phenotype animals as ‘depressed’. As a follow up to that report, we now present an analysis of the use of the FST over the past three years. This literature analysis shows that the popularity of the FST is still increasing and that the majority of researchers qualifies the rodent’s floating response as depressive-like behavior. However, over the past few years we also note a trend to interpret immobility rather as the expression of a coping strategy. In view of this result, we have sent a poll to the relevant authors to learn how consistent they are in naming FST behavior. Remarkably, we find a dramatic inverse correlation between their first qualification of acquired immobility as depressive-like behavior towards their current interpretation as coping strategy. In this contribution we have embedded our literature analysis and poll results in an update on the management of coping with inescapable stressors by processing in prefrontal cortical circuitry and glucocorticoid feedback. Show less
Molendijk, M.L.; Fried, E.I.; Does, W. van der 2018
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... Show moreThe 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. Show less