REM sleep is related to the transfer of implicit procedural knowledge following metacognitive learning

Objective: The hypothesis that REM sleep is also related to the transfer of implicit procedural knowledge was tested. Methods: A total of 21female adults (mean age: 19.49years) took part in the study. After a baseline night, participants were randomly assigned to one of two conditions to solve a cognitive procedural task (Tower of Hanoi problem; ToH); on the evening of the assessment night, one group solved the cognitive procedural task with and one group solved the task without metacognitive stimulation. The morning after the assessment night, participants solved three further transfer tasks (ToH with more disks; the Hobbits and Orcs problem; Katona's card problem). Results: Participants with metacognitive stimulation showed an increased performance in all three transfer tasks. Moreover, these participants had a significantly increased REM sleep. Conclusion: REM sleep seems to be related to metacognitively acquired implicit procedural knowledge. The transfer of the acquired implicit procedural knowledge does not seem to be limited to structurally similar task

Differences in maladaptive schemas between patients suffering from chronic and acute posttraumatic stress disorder and healthy controls

War, as a stressor event, has a variety of acute and chronic negative consequences, such as posttraumatic stress disorder (PTSD). In this context, early maladaptive schema-based problems in PTSD have recently become an important research area. The aim of this study was to assess early maladaptive schemas in patients with acute and chronic PTSD.; Using available sampling methods and diagnostic criteria, 30 patients with chronic PTSD, 30 patients with acute PTSD, and 30 normal military personnel who were matched in terms of age and wartime experience were selected and assessed with the Young Schema Questionnaire-Long Form, Beck Depression Inventory second version (BDI-II), the Beck Anxiety Inventory (BAI), and the Impact of Events Scale (IES).; Both acute and chronic PTSD patients, when compared with normal military personnel, had higher scores for all early maladaptive schemas. Additionally, veterans suffering from chronic PTSD, as compared with veterans suffering from acute PTSD and veterans without PTSD, reported more impaired schemas related, for instance, to Self-Control, Social Isolation, and Vulnerability to Harm and Illness.; The results of the present study have significant preventative, diagnostic, clinical, research, and educational implications with respect to PTSD

Sleep duration and subjective psychological well-being in adolescence: a longitudinal study in Switzerland and Norway

Adolescents' sleep duration and subjective psychological well-being are related. However, few studies have examined the relationship between sleep duration and subjective psychological well-being longitudinally across adolescence - a time of profound biological and psychosocial change. The aim of this longitudinal study was to investigate whether shorter sleep duration in adolescents is predictive of lower subjective psychological well-being 6 months and 12 months later or whether lower subjective psychological well-being is predictive of shorter sleep duration.; Adolescents (age range, 10.02-15.99 years; mean age, 13.05±1.49 years; 51.8%, female) from German-speaking Switzerland (n=886) and Norway (n=715) reported their sleep duration and subjective psychological well-being on school days using self-rating questionnaires at baseline (T1), 6 months (T2), and 12 months from baseline (T3).; Cross-sectional and longitudinal analyses revealed that sleep duration decreased with age. Longer sleep duration was concurrently associated with better subjective psychological well-being. Crossed-lagged autoregressive longitudinal panel analysis showed that sleep duration prospectively predicted subjective psychological well-being while there was no evidence for the reverse relationship.; Sleep duration is predictive of subjective psychological well-being. The findings offer further support for the importance of healthy sleep patterns during adolescence

Letters to the Editor

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66389/1/j.1600-0447.1989.tb03017.x.pd

Examining Dark Triad traits in relation to mental toughness and physical activity in young adults

Objective: The Dark Triad (DT) describes a set of three closely related personality traits: Machiavellianism, narcissism, and psychopathy. Mental toughness (MT) refers to a psychological construct combining confidence, commitment, control, and challenge. High MT is related to greater physical activity (PA) and, relative to men, women have lower MT scores. The aims of the present study were 1) to investigate the association between DT, MT, and PA, and 2) to compare the DT, MT, and PA scores of men and women. Methods: A total of 341 adults (M=29 years; 51.6% women; range: 18–37 years) took part in the study. Participants completed a series of questionnaires assessing DT, MT, and PA. Results: Machiavellianism, narcissism, and psychopathy were all significantly associated with higher MT scores (rs =0.45, 0.50, and 0.20, respectively). DT traits and MT were associated with more vigorous PA. Compared to men, women participants had lower scores for DT traits (overall score and psychopathy), while no differences were found for MT or PA in both sexes. Conclusion: DT traits, high MT, and vigorous PA are interrelated. This pattern of results might explain why, for instance, successful professional athletes can at the same time be tough and ruthless

Long-term outcomes of physical activity counseling in in-patients with major depressive disorder: results from the PACINPAT randomized controlled trial.

Major depressive disorder (MDD) is an increasingly common psychiatric illness associated with a high risk of insufficient physical activity, which in turn is associated with negative mental and physical health outcomes. Theory-based, individually tailored, in-person and remote physical activity counseling has the potential to increase physical activity levels in various populations. Given this, the present study investigated the effect of such a physical activity intervention on the physical activity behavior of in-patients with MDD. This was a multi-center, two-arm randomized controlled trial including initially insufficiently physically active adult in-patients with MDD from four study sites in Switzerland. The sample consisted of 220 participants (Mage = 41 ± 12.6 years, 52% women), 113 of whom were randomized to the intervention group and 107 to the control group. The main outcome, moderate-to-vigorous physical activity (MVPA), was assessed at three time points via hip-worn accelerometer. According to accelerometer measures, there was no significant difference in minutes spent in MVPA over a 12-month intervention period when comparing the intervention with the control group (β = -1.02, 95% CI = -10.68 to 8.64). Higher baseline physical activity significantly predicted physical activity at post and follow-up. This study showed that it is feasible to deliver an individually tailored, theory-based physical activity counseling intervention to in-patients with MDD, however yielding no significant effects on accelerometer-based MVPA levels. Further efforts are warranted to identify efficacious approaches.Trial registration: ISRCTN, ISRCTN10469580, registered on 3rd September 2018, https://www.isrctn.com/ISRCTN10469580

The Combined Dexamethasone/CRH Test (DEX/CRH Test) and Prediction of Acute Treatment Response in Major Depression

In this study the predictive value of the combined dexamethasone/CRH test (DEX/CRH test) for acute antidepressant response was investigated. In 114 depressed inpatients suffering from unipolar or bipolar depression (sample 1) the DEX/CRH test was performed at admission and shortly before discharge. During their stay in the hospital patients received different antidepressant treatment regimens. At admission, the rate of nonsuppression (basal cortisol levels >75.3 nmol/l) was 24.6% and was not related to the later therapeutic response. Moreover, 45 out of 114 (39.5%) patients showed an enhancement of HPA axis function at discharge in spite of clinical improvement. In a second sample, 40 depressed patients were treated either with reboxetine or mirtazapine for 5 weeks. The DEX/CRH test was performed before, after 1 week, and after 5 weeks of pharmacotherapy. Attenuation of HPA axis activity after 1 week was associated with a more pronounced alleviation of depressive symptoms after 5-week mirtazapine treatment, whereas downregulation of HPA system activity after 5 weeks was related to clinical response to reboxetine. However, early improvement of HPA axis dysregulation was not necessarily followed by a beneficial treatment outcome. Taken together, performance of a single DEX/CRH test does not predict the therapeutic response. The best predictor for response seems to be an early attenuation of HPA axis activity within 1 or 2 weeks. However, early improvement of HPA system dysfunction is not a sufficient condition for a favourable response. Since a substantial part of depressive patients display a persistence of HPA axis hyperactivity at discharge, downregulation of HPA system function is not a necessary condition for acute clinical improvement either. Our data underline the importance of HPA axis dysregulation for treatment outcome in major depression, although restoration of HPA system dysfunction seems to be neither a necessary nor a sufficient determinant for acute treatment response

Orexin Receptor Antagonism, a New Sleep-Enabling Paradigm: A Proof-of-Concept Clinical Trial

Peer reviewe

Dendritic Morphology of Hippocampal and Amygdalar Neurons in Adolescent Mice Is Resilient to Genetic Differences in Stress Reactivity

Many studies have shown that chronic stress or corticosterone over-exposure in rodents leads to extensive dendritic remodeling, particularly of principal neurons in the CA3 hippocampal area and the basolateral amygdala. We here investigated to what extent genetic predisposition of mice to high versus low stress reactivity, achieved through selective breeding of CD-1 mice, is also associated with structural plasticity in Golgi-stained neurons. Earlier, it was shown that the highly stress reactive (HR) compared to the intermediate (IR) and low (LR) stress reactive mice line presents a phenotype, with respect to neuroendocrine parameters, sleep architecture, emotional behavior and cognition, that recapitulates some of the features observed in patients suffering from major depression. In late adolescent males of the HR, IR, and LR mouse lines, we observed no significant differences in total dendritic length, number of branch points and branch tips, summated tip order, number of primary dendrites or dendritic complexity of either CA3 pyramidal neurons (apical as well as basal dendrites) or principal neurons in the basolateral amygdala. Apical dendrites of CA1 pyramidal neurons were also unaffected by the differences in stress reactivity of the animals; marginally higher length and complexity of the basal dendrites were found in LR compared to IR but not HR mice. In the same CA1 pyramidal neurons, spine density of distal apical tertiary dendrites was significantly higher in LR compared to IR or HR animals. We tentatively conclude that the dendritic complexity of principal hippocampal and amygdala neurons is remarkably stable in the light of a genetic predisposition to high versus low stress reactivity, while spine density seems more plastic. The latter possibly contributes to the behavioral phenotype of LR versus HR animals