360 research outputs found

    Number-conserving master equation theory for a dilute Bose-Einstein condensate

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    We describe the transition of NN weakly interacting atoms into a Bose-Einstein condensate within a number-conserving quantum master equation theory. Based on the separation of time scales for condensate formation and non-condensate thermalization, we derive a master equation for the condensate subsystem in the presence of the non-condensate environment under the inclusion of all two body interaction processes. We numerically monitor the condensate particle number distribution during condensate formation, and derive a condition under which the unique equilibrium steady state of a dilute, weakly interacting Bose-Einstein condensate is given by a Gibbs-Boltzmann thermal state of NN non-interacting atoms

    Dopamine receptor 4 promoter polymorphism modulates memory and neuronal responses to salience

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    Animal models and human functional imaging data implicate the dopamine system in mediating enhanced encoding of novel stimuli into human memory. A separate line of investigation suggests an association between a functional polymorphism in the promoter region for the human dopamine 4 receptor gene (DRD4) and sensitivity to novelty. We demonstrate, in two independent samples, that the -521Cmayor queT DRD4 promoter polymorphism determines the magnitude of human memory enhancement for contextually novel, perceptual oddball stimuli in an allele dose-dependent manner. The genotype-dependent memory enhancement conferred by the C allele is associated with increased neuronal responses during successful encoding of perceptual oddballs in the ventral striatum, an effect which is again allele dose-dependent. Furthermore, with repeated presentations of oddball stimuli, this memory advantage decreases, an effect mirrored by adaptation of activation in the hippocampus and substantia nigra/ventral tegmental area in C carriers only. Thus, a dynamic modulation of human memory enhancement for perceptually salient stimuli is associated with activation of a dopaminergic-hippocampal system, which is critically dependent on a functional polymorphism in the DRD4 promoter region

    Disease burden and direct medical costs of incident adult ADHD:A retrospective longitudinal analysis based on German statutory health insurance claims data

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    Background. Adult attention-deficit/hyperactivity disorder (aADHD) is still a largely unrecognized psychiatric condition despite its strong impact on individuals' well-being. Here, we describe the healthcare situation of individuals with incident aADHD over 4 years before and 4 years after initial administrative diagnosis. Methods. A retrospective, longitudinal cohort analysis was conducted using German claims data. The InGef database contained approximately 5 million member-records from over 60 nationwide statutory health insurances (SHI). Individuals were indexed upon initial diagnosis of aADHD. Results. Average age at diagnosis of aADHD was 35 years, and 60% of individuals were male. Comorbidities, resource use, and healthcare costs were substantial before initial diagnosis and decreased within the 4 years thereafter. Only 32% of individuals received initial ADHD medication and adherence was low. The majority received psychotherapy. Individuals with initial ADHD medication showed the highest share in comorbidities, physician visits, medication use for comorbidities, psychotherapy, and costs. Overall, healthcare costs were at over euro4,000 per individual within the year of aADHD diagnosis. Conclusions. We conclude that earlier recognition of aADHD could prevent the development and aggravation of comorbid mental illnesses. At the same time, comorbid conditions may have masked ("over-shadowed") aADHD and delayed diagnosis. The burden of disease in aADHD is high, which was noticeable especially among individuals who received initial ADHD-medication, suggesting that psychopharmacological treatment was mainly considered for the most severely ill. We conclude that measures to facilitate access of aADHD patients to clinical experts are required to improve reality of care in the outpatient setting

    Classes of depression symptom trajectories in patients with major depression receiving a collaborative care intervention

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    Purpose Collaborative care is effective in improving symptoms of patients with depression. The aims of this study were to characterize symptom trajectories in patients with major depression during one year of collaborative care and to explore associations between baseline characteristics and symptom trajectories. Methods We conducted a cluster-randomized controlled trial in primary care. The collaborative care intervention comprised case management and behavioral activation. We used the Patient Health Questionnaire-9 (PHQ-9) to assess symptom severity as the primary outcome. Statistical analyses comprised latent growth mixture modeling and a hierarchical binary logistic regression model. Results We included 74 practices and 626 patients (310 intervention and 316 control recipients) at baseline. Based on a minimum of 12 measurement points for each intervention recipient, we identified two latent trajectories, which we labeled \u27fast improvers\u27 (60.5%) and \u27slow improvers\u27 (39.5%). At all measurements after baseline, \u27fast improvers\u27 presented higher PHQ mean values than \u27slow improvers\u27. At baseline, \u27fast improvers\u27 presented fewer physical conditions, higher health-related quality of life, and had made fewer suicide attempts in their history. Conclusions A notable proportion of 39.5% of patients improved only \u27slowly\u27 and probably needed more intense treatment. The third follow-up in month two could well be a sensible time to adjust treatment to support \u27slow improvers\u27. (DIPF/Orig.

    Digitalisation anxiety: development and validation of a new scale

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    <jats:title>Abstract</jats:title><jats:p>The increasing spread of digital technologies and respective consequences for the way we live, work, and communicate can evoke feelings of tension and discomfort. This so-called digitalisation anxiety is related to existing and future technologies, includes the process of digitalisation in everyday life, and refers to multiple levels (the individual, organisations, and society). Existing scales measuring technology-related fears due not adequately reflect these features. Therefore, we developed the German version of the Digitalisation Anxiety Scale (DAS). Having generated items based on a qualitative interview study (Study 1, n = 26), we demonstrated the DAS’s factor structure, internal consistency and construct validity in Study 2a (n = 109) and test-retest reliability in Study 2b (n = 30). In Study 3 (n = 223), the scale’s structure was confirmed and correlates of digitalisation anxiety were examined. The final version of the DAS consists of 35 items with a four-factor structure (societal triggers for digitalisation anxiety, triggers related to interaction and leadership, triggers within oneself and triggers resulting from the digitalisation implementation process). Digitalisation Anxiety had negative relationships with well-being and performance. The scale allows practitioners and researchers to measure and benchmark individuals’ levels of digitalisation anxiety, and to track changes over time. The scale can inform interventions aiming at reducing digitalisation anxiety and stress resulting from digitalisation. </jats:p&gt

    Establishing an effective dose for chronic intracerebroventricular administration of clozapine in mice

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    Objective:Despite its numerous side effects, clozapine is still the most effective antipsychotics making it an ideal reference substance to validate the efficacy of novel compounds for the treatment of schizophrenia. However, blood–brain barrier permeability for most new molecular entities is unknown, requiring central delivery. Thus, we performed a dose-finding study for chronic intracerebroventricular (icv) delivery of clozapine in mice.Methods:Specifically, we implanted wild-type C57BL/6J mice with osmotic minipumps (Alzet) delivering clozapine at a rate of 0.15 µl/h at different concentrations (0, 3.5, 7 and 14 mg/ml, i.e. 0, 12.5, 25 and 50 µg/day). Mice were tested weekly in a modified SHIRPA paradigm, for locomotor activity in the open field and for prepulse inhibition (PPI) of the acoustic startle response (ASR) for a period of 3 weeks.Results:None of the clozapine concentrations caused neurological deficits or evident gross behavioural alterations in the SHIRPA paradigm. In male mice, clozapine had no significant effect on locomotor activity or PPI of the ASR. In female mice, the 7 and 14 mg/ml dose of clozapine significantly affected both open field activity and PPI, while 3.5 mg/ml of clozapine increased PPI but had no effects on locomotor activity.Conclusion:Our findings indicate that 7 mg/ml may be the optimal dose for chronic icv delivery of clozapine in mice, allowing comparison to screen for novel antipsychotic compounds.</p

    Generalization of Conditioned Contextual Anxiety and the Modulatory Effects of Anxiety Sensitivity

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    Anxiety patients overgeneralize fear responses, possibly because they cannot distinguish between cues never been associated with a threat (i.e., safe) and threat-associated cues. However, as contexts and not cues are discussed as the relevant triggers for prolonged anxiety responses characterizing many anxiety disorders, we speculated that it is rather overgeneralization of contextual anxiety, which constitutes a risk factor for anxiety disorders. To this end, we investigated generalization of conditioned contextual anxiety and explored modulatory effects of anxiety sensitivity, a risk factor for anxiety disorders. Fifty-five participants underwent context conditioning in a virtual reality paradigm. On Day 1 (acquisition), participants received unpredictable mildly painful electric stimuli (unconditioned stimulus, US) in one virtual office (anxiety context, CTX+), but never in a

    White matter abnormalities in the fornix are linked to cognitive performance in SZ but not in BD disorder: An exploratory analysis with DTI deterministic tractography

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    Background In psychosis, white matter (WM) microstructural changes have been detected previously; however, direct comparisons of findings between bipolar (BD) and schizophrenia (SZ) patients are scarce. In this study, we employed deterministic tractography to reconstruct WM tracts in BD and SZ patients. Methods Diffusion tensor imaging (DTI) data was carried out with n=32 euthymic BD type I patients, n=26 SZ patients and 30 matched healthy controls. Deterministic tractography using multiple indices of diffusion (fractional anisotropy (FA), tract volume (Vol), tract length (Le) and number of tracts (NofT)) were obtained from the fornix, the cingulum, the anterior thalamic radiation, and the corpus callosum bilaterally. Results We showed widespread WM microstructural changes in SZ, and changes in the corpus callosum, the left cingulum and the fornix in BD. Fornix fiber tracking scores were associated with cognitive performance in SZ, and with age and age at disease onset in the BD patient group. Limitations Although the influence of psychopharmacological drugs as biasing variables on morphological alterations has been discussed for SZ and BD, we did not observe a clear influence of drug exposure on our findings. Conclusions These results confirm the assumption that SZ patients have more severe WM changes than BD patients. The findings also suggest a major role of WM changes in the fornix as important fronto-limbic connections in the etiology of cognitive symptoms in SZ, but not in B

    Hippocampal overexpression of NOS1AP promotes endophenotypes related to mental disorders.

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    BACKGROUND Nitric oxide synthase 1 adaptor protein (NOS1AP; previously named CAPON) is linked to the glutamatergic postsynaptic density through interaction with neuronal nitric oxide synthase (nNOS). NOS1AP and its interaction with nNOS have been associated with several mental disorders. Despite the high levels of NOS1AP expression in the hippocampus and the relevance of this brain region in glutamatergic signalling as well as mental disorders, a potential role of hippocampal NOS1AP in the pathophysiology of these disorders has not been investigated yet. METHODS To uncover the function of NOS1AP in hippocampus, we made use of recombinant adeno-associated viruses to overexpress murine full-length NOS1AP or the NOS1AP carboxyterminus in the hippocampus of mice. We investigated these mice for changes in gene expression, neuronal morphology, and relevant behavioural phenotypes. FINDINGS We found that hippocampal overexpression of NOS1AP markedly increased the interaction of nNOS with PSD-95, reduced dendritic spine density, and changed dendritic spine morphology at CA1 synapses. At the behavioural level, we observed an impairment in social memory and decreased spatial working memory capacity. INTERPRETATION Our data provide a mechanistic explanation for a highly selective and specific contribution of hippocampal NOS1AP and its interaction with the glutamatergic postsynaptic density to cross-disorder pathophysiology. Our findings allude to therapeutic relevance due to the druggability of this molecule. FUNDING This study was funded in part by the DFG, the BMBF, the Academy of Finland, the NIH, the Japanese Society of Clinical Neuropsychopharmacology, the Ministry of Education of the Russian Federation, and the European Community

    On the role of NOS1 ex1f-VNTR in ADHD – allelic, subgroup, and meta-analysis

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    Attention deficit/hyperactivity disorder (ADHD) is a heritable neurodevelopmental disorder featuring complex genetics with common and rare variants contributing to disease risk. In a high proportion of cases, ADHD does not remit during adolescence but persists into adulthood. Several studies suggest that NOS1, encoding nitric oxide synthase I, producing the gaseous neurotransmitter NO, is a candidate gene for (adult) ADHD. We here extended our analysis by increasing the original sample, adding two further samples from Norway and Spain, and conducted subgroup and co-morbidity analysis. Our previous finding held true in the extended sample, and also meta-analysis demonstrated an association of NOS1 ex1fVNTR short alleles with adult ADHD (aADHD). Association was restricted to females, as was the case in the discovery sample. Subgroup analysis on the single allele level suggested that the repeat allele caused the association. Regarding subgroups, we found that NOS1 was associated with the hyperactive/impulsive ADHD subtype, but not to pure inattention. In terms of comorbidity, major depression, anxiety disorders, cluster C personality disorders and migraine were associated with short repeats, in particular the repeat allele. Also, short allele carriers had significantly lower IQ. Finally, we again demonstrated an influence of the repeat on gene expression in human post-mortem brain samples. These data validate the role of NOS-I in hyperactive/impulsive phenotypes and call for further studies into the neurobiological underpinnings of this association.PostprintPeer reviewe
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