Generalized Anxiety Disorder: Comorbidity, Comparative Biology and Treatment

Generalized anxiety disorder (GAD) is a severe and chronic anxiety disorder characterized by uncontrollable worrying and somatic anxiety (tension, insomnia and hypervigilance). It is a common condition, with lifetime prevalence rates for DSM-IV GAD in the general population of approx. 5–6% being reported. In addition, like other anxiety disorders, GAD also shows comorbidity with depression and most of the other anxiety disorders. This article reviews data on the prevalence of GAD, its comorbidity with depression, and its social and economic impact. Proposed neurobiological mechanisms for GAD are discussed, since an understanding of these may help in the development of future therapies. Finally, current pharmacological and non-pharmacological treatment options for GAD are reviewed, with particular attention being paid to published clinical-trial data

Medical cannabis for severe treatment resistant epilepsy in children: a case-series of 10 patients

Objectives To report the findings of a case-series of 10 children suffering with intractable epilepsies in the UK to determine the feasibility for using whole-plant cannabis medicines to treat seizures in children. Setting This study was conducted retrospectively through collecting clinical data from caretakers and clinicians on study outcome variables. Participants were recruited through the MedCann Support and End our Pain charity groups which are patient representative groups that support children who are using medical cannabis to treat their epilepsies. Medicines were prescribed to patients by clinicians in both National Health Service and private medical practices. Follow-up calls were conducted throughout the period January 2021 to May 2021 to keep data recorded up to date. Participants Ten children, 18 years old or under, with intractable epilepsies were recruited from two charities. There were no limitations on diagnosis, sex or ethnic origin. Interventions Participants were treated with a range of whole-plant medical cannabis oils. Individual dosing regimens were determined by clinicians. Primary outcome measure The primary outcome measure was seizure frequency. Results Seizure frequency across all 10 participants reduced by 86% with no significant adverse events. Participants reduced use of antiepileptic drugs from an average of seven to one following treatment with medical cannabis. We also noted significant financial costs of £874 per month to obtain these medicines through private prescriptions. Conclusions This study establishes the feasibility of whole-plant medical cannabis as an effective and well-tolerated medicine for reducing seizure frequency in children suffering with intractable epilepsies. These findings justify the potential value of further research into the reported therapeutic benefit of whole-plant medicinal cannabis products

Early appearance of germinal center–derived memory B cells and plasma cells in blood after primary immunization

Immunization with a T cell–dependent antigen elicits production of specific memory B cells and antibody-secreting cells (ASCs). The kinetic and developmental relationships between these populations and the phenotypic forms they and their precursors may take remain unclear. Therefore, we examined the early stages of a primary immune response, focusing on the appearance of antigen-specific B cells in blood. Within 1 wk, antigen-specific B cells appear in the blood with either a memory phenotype or as immunoglobulin (Ig)G1 ASCs expressing blimp-1. The memory cells have mutated VH genes; respond to the chemokine CXCL13 but not CXCL12, suggesting recirculation to secondary lymphoid organs; uniformly express B220; show limited differentiation potential unless stimulated by antigen; and develop independently of blimp-1 expression. The antigen-specific IgG1 ASCs in blood show affinity maturation paralleling that of bone marrow ASCs, raising the possibility that this compartment is established directly by blood-borne ASCs. We find no evidence for a blimp-1–expressing preplasma memory compartment, suggesting germinal center output is restricted to ASCs and B220+ memory B cells, and this is sufficient to account for the process of affinity maturation

The development and validation of a human screening model of tobacco abstinence

Introduction Given the low efficacy of smoking cessation methods, an experimental medicine model indicating smoking abstinence would be of great benefit to the development of new treatments. Hence the sensitivity of cognitive tasks and ambulatory craving measures to smoking abstinence were investigated. Methods Cognitive tasks and ambulatory ratings of craving were assessed for sensitivity to acute abstinence (experiment 1), and nicotine replacement therapy administration (NRT) (experiment 2). Results In experiment 1 go/no-go performance was improved (Mean Difference [MD] -0.99, 95% CI: −1.90 to −0.08) and craving was lower (Regression Coefficient [RC] −33.39, 95% CI: -39.96 to -26.82) in satiated compared with abstinent smokers. There was no clear evidence that N-back (MD 0.64, 95% CI: −0.42 to 2.51), delay discounting (MD 0.01, 95% CI: 0.001 to 0.005) or dot probe performance (MD 0.61, 95% CI: −0.87 to 1.54) were sensitive to acute abstinence. In experiment 2 go/no-go performance was improved (MD 1.12, 95% CI: 0.16–2.08) and craving was lower (RC −18.59, 95% CI: −24.63 to −12.55) smokers abstinent overnight receiving NRT compared with placebo. There was no clear evidence that N-back (MD −0.25, 95% CI: −1.45 to 0.94), delay discounting (MD 0.01, 95% CI: -0.002 to 0.004) or dot probe performance (MD −0.49, 95% CI: −1.61 to −0.64) were sensitive to NRT. Conclusions Findings from two experiments converge to suggest that abstinence in smokers reliably increases ambulatory craving assessments and, to a lesser extent, decreases go/no-go task performance. These findings can be utilized in the development of an experimental medicine model to test novel treatments for smoking cessation

Bupropiooni augmentatsiooni toime estsitalopraamravi suhtes resistentsetel depressiivsetel patsientidel

Üha enam on andmeid, et bupropioon on üks efektiivsemaid valikuid augmentatsiooniks neil depressiivsetel patsientidel, kes serotoniini tagasihaarde inhibiitoritele reageerivad osaliselt või mitteküllaldaselt. Käesolevas uuringus jälgiti bupropiooni augmentatsiooni efektiivsust ja talutavust estsitalopraamravile mittereageerinud patsientidel. Seisundi kliinilist raskusastet ja paranemist hinnati kahenädalase intervalliga, kasutades selleks erinevaid skaalasid. Patsiendid hindasid sümptomeid ja võimalikke kõrvaltoimeid enesehinnangulistel skaaladel. Sarnaselt eelnevate uuringutega leiti, et bupropiooni augmentatsioon oli üldiselt hästi talutav ja aitas edukalt saada ravivastust enamikul serotoniini tagasihaarde inhibiitori monoteraapia suhtes resistentsetel patsientidel. Melanhoolset tüüpi depressioon oli seotud ebapiisava või osalise ravivastusega estsitalopraamile. Tulemused toetasid seisukohta, et bupropioon on esmavaliku antidepressant melanhoolse depressiooni ravis. Eesti Arst 2009; 88(2):82−9

Characterisation of the contribution of the GABA-benzodiazepine α1 receptor subtype to [11C]Ro15-4513 PET images

This positron emission tomography (PET) study aimed to further define selectivity of [11C]Ro15-4513 binding to the GABARα5 relative to the GABARα1 benzodiazepine receptor subtype. The impact of zolpidem, a GABARα1-selective agonist, on [11C]Ro15-4513, which shows selectivity for GABARα5, and the nonselective benzodiazepine ligand [11C]flumazenil binding was assessed in humans. Compartmental modelling of the kinetics of [11C]Ro15-4513 time-activity curves was used to describe distribution volume (VT) differences in regions populated by different GABA receptor subtypes. Those with low α5 were best fitted by one-tissue compartment models; and those with high α5 required a more complex model. The heterogeneity between brain regions suggested spectral analysis as a more appropriate method to quantify binding as it does not a priori specify compartments. Spectral analysis revealed that zolpidem caused a significant VT decrease (∼10%) in [11C]flumazenil, but no decrease in [11C]Ro15-4513 binding. Further analysis of [11C]Ro15-4513 kinetics revealed additional frequency components present in regions containing both α1 and α5 subtypes compared with those containing only α1. Zolpidem reduced one component (mean±s.d.: 71%±41%), presumed to reflect α1-subtype binding, but not another (13%±22%), presumed to reflect α5. The proposed method for [11C]Ro15-4513 analysis may allow more accurate selective binding assays and estimation of drug occupancy for other nonselective ligands

The value of real world evidence: the case of medical cannabis

Randomised controlled trials (RCTs) have long been considered the gold standard of medical evidence. In relation to cannabis based medicinal products (CBMPs), this focus on RCTs has led to very restrictive guidelines in the UK, which are limiting patient access. There is general agreement that RCT evidence in relation to CBPMs is insufficient at present. As well as commercial reasons, a major problem is that RCTs do not lend themselves well to the study of whole plant medicines. One solution to this challenge is the use of real world evidence (RWE) with patient reported outcomes (PROs) to widen the evidence base. Such data increasingly highlights the positive impact medical cannabis can have on patients’ lives. This paper outlines the value of this approach which involves the study of interventions and patients longitudinally under medical care. In relation to CBMPs, RWE has a broad range of advantages. These include the study of larger groups of patients, the use of a broader range and ratio of components of CBMPs, and the inclusion of more and rarer medical conditions. Importantly, and in contrast to RCTs, patients with significant comorbidities–and from a wider demographic profile–can also be studied, so providing higher ecological validity and increasing patient numbers, whilst offering significant cost savings. We conclude by outlining 12 key recommendations of the value of RWE in relation to medical cannabis. We hope that this paper will help policymakers and prescribers understand the importance of RWE in relation to medical cannabis and help them develop approaches to overcome the current situation which is detrimental to patients