Unleashing the full power of LHCb to probe stealth new physics.

In this paper, we describe the potential of the LHCb experiment to detect stealth physics. This refers to dynamics beyond the standard model that would elude searches that focus on energetic objects or precision measurements of known processes. Stealth signatures include long-lived particles and light resonances that are produced very rarely or together with overwhelming backgrounds. We will discuss why LHCb is equipped to discover this kind of physics at the Large Hadron Collider and provide examples of well-motivated theoretical models that can be probed with great detail at the experiment.

['I'm in hate with you; epistemic distrust in patients with a severe personality disorder]. / 'Ik haat van jou'; epistemisch wantrouwen bij mensen met een ernstige persoonlijkheidsstoornis.

Background The assessment and treatment of patients with a personality disorder have made considerable progress during the last decades. Unfortunately, this progress is often limited to patients with a personality disorder in general. Patients with a personality disorder who also fulfil criteria for a severe mental illness (SMI-PD) profit less. Aim To describe the relationship between contemporary paradigms about personality disorders and the current treatment practices of patients with SMI-PD, and to assess the added value of the recently introduced paradigm epistemic trust and distrust. Method An expert group of mental health professionals, all members of the Expertise Centre for Personality Disorders, conducted a literature study and in addition organized an invitational conference and consensus meetings, resulting in an analysis and recommendations for treatment of patients with SMI-PD. Results The epistemic trust and distrust paradigm clarifies the learning process of patients with SMI-PD and the way patients benefit from treatment. We conclude with elaborations of this paradigm for five contexts of patients with SMI-PD. Conclusion The epistemic trust and distrust paradigm seems a promising concept to improve the often difficult treatment of patients with SMI-PD.

Can chronotype function as predictor of a persistent course of depressive and anxiety disorder?

BACKGROUND: The role of chronotype, the individual timing of sleep/activity, has been studied in relation to depressive and anxiety disorders. A cross-sectional association between a depressive episode and evening-type has been identified. However, until now the predicting capacity of chronotype concerning persistence of psychiatric disorders remains unclear. Our aim is to examine whether a later chronotype in patients with a depressive and/or anxiety disorder can serve as a predictor of a persistent course. METHODS: A subsample of patients with a depressive and/or anxiety disorder diagnosis and chronotype data of the longitudinal Netherlands Study of Depression and Anxiety (NESDA) was used. Diagnosis of depressive and anxiety disorders (1-month DSM-IV based diagnosis) were determined at baseline (n = 505). From this group persistence was determined at 2-year (FU2) (persistent course: n = 248, non-persistent course: n = 208) and 4-year follow-up (FU4) (persistent course: n = 151, non-persistent course: n = 264). Chronotype was assessed at baseline with the Munich Chronotype Questionnaire. RESULTS: A later chronotype did not predict a persistent course of depressive and/or anxiety disorder at FU2 (OR (95% CI) = 0.99 (0.83-1.19), P = 0.92) or at FU4 (OR (95% CI) = 0.94 (0.77-1.15), P = 0.57). LIMITATIONS: Persistence was defined as having a diagnosis of depressive and/or anxiety disorder at the two-year and four-year follow-up, patients may have remitted and relapsed between assessments. CONCLUSION: Chronotype, measured as actual sleep timing, of patients with a depressive or anxiety disorder did not predict a persistent course which suggests it might be unsuitable as predictive tool in clinical settings.

The duration of light treatment and therapy outcome in seasonal affective disorder.

BACKGROUND: Seasonal affective disorder (SAD) is characterized by recurrent episodes of major depression with a seasonal pattern, treated with light therapy (LT). Duration of light therapy differs. This study investigates retrospectively whether a single week of LT is as effective as two weeks, whether males and females respond differently, and whether there is an effect of expectations as assessed before treatment. METHODS: 83 women, and 25 men received either one-week (n=42) or two weeks (n=66) of LT were included in three studies. Before LT, patients׳ expectations on therapy response were assessed. RESULTS: Depression severity was similar in both groups before treatment (F(1,106)=0.19ns) and decreased significantly during treatment (main effect "time" F(2,105)=176.7, p<0.001). The speed of therapy response differs significantly in treatment duration, in favor of 1 week (F(2,105)=3.2, p=0.046). A significant positive correlation between expectations and therapy response was found in women (ρ=0.243, p=0.027) and not in men (ρ=-0.154,ns). When expectation was added as a covariate in the repeated-measures analysis it shows a positive effect of the level of expectation on the speed of therapy response (F(2,104)=4.1, p=0.018). LIMITATIONS: A limitation is the retrospective design. CONCLUSIONS: There is no difference between 1 and 2 weeks of LT in overall therapy outcome, but the speed of therapy response differed between 1 week LT and 2 weeks LT. Together with the significant correlation between expectations and therapy response in women, we hypothesize that expectations play a role in the speed of therapy response.