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Anxiety disorders (separation anxiety disorder, selective mutism, specific phobias, social anxiety disorder, panic disorder, agoraphobia, and generalised anxiety disorder) are common and disabling conditions that mostly begin during childhood, adolescence, and early adulthood. They differ from developmentally normative or stress-induced transient anxiety by being marked (ie, out of proportion to the actual threat present) and persistent, and by impairing daily functioning. Most anxiety disorders affect almost twice as many women as men. They often co-occur with major depression, alcohol and other substance-use disorders, and personality disorders. Differential diagnosis from physical conditions—including thyroid, cardiac, and respiratory disorders, and substance intoxication and withdrawal—is imperative. If untreated, anxiety disorders tend to recur chronically. Psychological treatments, particularly cognitive behavioural therapy, and pharmacological treatments, particularly selective serotonin-reuptake inhibitors and serotonin–noradrenaline-reuptake inhibitors, are effective, and their combination could be more effective than is treatment with either individually. More research is needed to increase access to and to develop personalised treatments.

The potassium isotope signature of lunar rocks supports the model of a high-energy giant impact as the origin of the Moon. A high-energy giant impact origin for the Moon Kun Wang and Stein Jacobsen report high-precision potassium isotope data for the Earth, the Moon and chondritic meteorites, and show that lunar rocks are significantly enriched in the heavy isotopes of potassium compared to the Earth and chondrites. They conclude that this enrichment can be best explained as the result of the incomplete condensation of a silicate vapour during the Moon-forming giant impact event, at a relatively high ambient pressure. Such conditions would be consistent with the high-energy, high-angular-momentum giant impact model for the origin of the Moon. The Earth–Moon system has unique chemical and isotopic signatures compared with other planetary bodies 1 , 2 , 3 ; any successful model for the origin of this system therefore has to satisfy these chemical and isotopic constraints. The Moon is substantially depleted in volatile elements such as potassium compared with the Earth and the bulk solar composition 4 , and it has long been thought to be the result of a catastrophic Moon-forming giant impact event 5 . Volatile-element-depleted bodies such as the Moon were expected to be enriched in heavy potassium isotopes during the loss of volatiles; however such enrichment was never found 6 . Here we report new high-precision potassium isotope data for the Earth, the Moon and chondritic meteorites. We found that the lunar rocks are significantly (>2 σ ) enriched in the heavy isotopes of potassium compared to the Earth and chondrites (by around 0.4 parts per thousand). The enrichment of the heavy isotope of potassium in lunar rocks compared with those of the Earth and chondrites can be best explained as the result of the incomplete condensation of a bulk silicate Earth vapour at an ambient pressure that is higher than 10 bar. We used these coupled constraints of the chemical loss and isotopic fractionation of K to compare two recent dynamic models that were used to explain the identical non-mass-dependent isotope composition of the Earth and the Moon. Our K isotope result is inconsistent with the low-energy disk equilibration model 7 , but supports the high-energy, high-angular-momentum giant impact model 8 for the origin of the Moon. High-precision potassium isotope data can also be used as a ‘palaeo-barometer’ to reveal the physical conditions during the Moon-forming event.

Early silicate differentiation events for the terrestrial planets can be traced with the short-lived 146Sm-142Nd system (∼100-My half-life). Resulting early Earth-produced 142Nd/144Nd variations are an excellent tracer of the rate of mantle mixing and thus a potential tracer of plate tectonics through time. Evidence for early silicate differentiation in the Hadean (4.6 to 4.0 Ga) has been provided by 142Nd/144Nd measurements of rocks that show both higher and lower (±20 ppm) values than the present-day mantle, demonstrating major silicate Earth differentiation within the first 100 My of solar system formation. We have obtained an external 2σ uncertainty at 1.7 ppm for 142Nd/144Nd measurements to constrain its homogeneity/heterogeneity in the mantle for the last 2 Ga. We report that most modern-day mid-ocean ridge basalt and ocean island basalt samples as well as continental crustal rocks going back to 2 Ga are within 1.7 ppm of the average Earth 142Nd/144Nd value. Considering mafic and ultramafic compositions, we use a mantle-mixing model to show that this trend is consistent with a mantle stirring time of about 400 My since the early Hadean. Such a fast mantle stirring rate supports the notion that Earth’s thermal and chemical evolution is likely to have been largely regulated by plate tectonics for most of its history. Some young rocks have 142Nd/144Nd signatures marginally resolved (∼3 ppm), suggesting that the entire mantle is not equally well homogenized and that some silicate mantle signatures from an early differentiated mantle (>4.1 Ga ago) are preserved in the modern mantle.

Our understanding of social anxiety disorder (also known as social phobia) has moved from rudimentary awareness that it is not merely shyness to a much more sophisticated appreciation of its prevalence, its chronic and pernicious nature, and its neurobiological underpinnings. Social anxiety disorder is the most common anxiety disorder; it has an early age of onset—by age 11 years in about 50% and by age 20 years in about 80% of individuals—and it is a risk factor for subsequent depressive illness and substance abuse. Functional neuroimaging studies point to increased activity in amygdala and insula in patients with social anxiety disorder, and genetic studies are increasingly focusing on this and other (eg, personality trait neuroticism) core phenotypes to identify risk loci. A range of effective cognitive behavioural and pharmacological treatments for children and adults now exists; the challenges lie in optimum integration and dissemination of these treatments, and learning how to help the 30–40% of patients for whom treatment does not work.

The radii and orbital periods of 4,000+ confirmed/candidate exoplanets have been precisely measured by the Kepler mission. The radii show a bimodal distribution, with two peaks corresponding to smaller planets (likely rocky) and larger intermediate-size planets, respectively. While only the masses of the planets orbiting the brightest stars can be determined by ground-based spectroscopic observations, these observations allow calculation of their average densities placing constraints on the bulk compositions and internal structures. However, an important question about the composition of planets ranging from 2 to 4 Earth radii (R⊕) still remains. They may either have a rocky core enveloped in a H₂–He gaseous envelope (gas dwarfs) or contain a significant amount of multicomponent, H₂O-dominated ices/fluids (water worlds). Planets in the mass range of 10–15 M⊕, if half-ice and half-rock by mass, have radii of 2.5 R⊕, which exactly match the second peak of the exoplanet radius bimodal distribution. Any planet in the 2- to 4-R⊕ range requires a gas envelope of at most a few mass percentage points, regardless of the core composition. To resolve the ambiguity of internal compositions, we use a growth model and conduct Monte Carlo simulations to demonstrate that many intermediate-size planets are “water worlds.”

Despite heightened awareness of the clinical significance of social phobia, information is still lacking about putative subtypes, functional impairment, and treatment-seeking. New epidemiologic data on these topics are presented from the National Comorbidity Survey Replication (NCS-R). The NCS-R is a nationally representative household survey fielded in 2001-2003. The World Health Organization (WHO) Composite International Diagnostic Interview Version 3.0 (CIDI 3.0) was used to assess 14 performance and interactional fears and DSM-IV social phobia. The estimated lifetime and 12-month prevalence of social phobia are 12.1% and 7.1% respectively. Performance and interactional fears load onto a single latent factor, and there is little evidence for distinct subtypes based either on the content or the number of fears. Social phobia is associated with significant psychiatric co-morbidity, role impairment, and treatment-seeking, all of which have a dose-response relationship with number of social fears. However, social phobia is the focus of clinical attention in only about half of cases where treatment is obtained. Among non-co-morbid cases, those with the most fears were least likely to receive social phobia treatment. Social phobia is a common, under-treated disorder that leads to significant functional impairment. Increasing numbers of social fears are associated with increasingly severe manifestations of the disorder.

At ocean spreading ridges, circulation of seawater through rock at elevated temperatures alters the chemical and isotopic composition of oceanic crust. Samples obtained from drilling into ocean floor and from ophiolites have demonstrated that certain isotope systems, such as 18O/16O and 87Sr/86Sr, are systematically modified in hydrothermally altered oceanic crust. Although K is known to be mobile during hydrothermal alteration, there have not yet been any K-isotope analyses of altered oceanic crustal materials.Moreover, the 41K/39K of seawater was recently found to be significantly higher than that of igneous rocks, so the addition of seawater K to oceanic crust would be expected to generate 41K/39K variations in affected rocks. Here, we report high-precision 41K/39K measurements for samples from the Bay of Islands ophiolite, and we document large variations in 41K/39K, covarying with previous determinations of 87Sr/86Sr. Our data indicate that analytically resolvable 41K/39K effects arise in oceanic crust as a result of hydrothermal alteration. This finding raises the possibility that 41K/39K can be used as an effective tracer of oceanic crust recycled into the mantle, as a diagnostic criterion by which to identify ancient fragments of oceanic crust, and as a constraint on the flux of K between oceanic crust and seawater.

Depression is a common psychiatric disorder and a leading cause of disability worldwide. Here we conducted a genome-wide association study meta-analysis of six datasets, including >1.3 million individuals (371,184 with depression) and identified 243 risk loci. Overall, 64 loci were new, including genes encoding glutamate and GABA receptors, which are targets for antidepressant drugs. Intersection with functional genomics data prioritized likely causal genes and revealed new enrichment of prenatal GABAergic neurons, astrocytes and oligodendrocyte lineages. We found depression to be highly polygenic, with ~11,700 variants explaining 90% of the single-nucleotide polymorphism heritability, estimating that >95% of risk variants for other psychiatric disorders (anxiety, schizophrenia, bipolar disorder and attention deficit hyperactivity disorder) were influencing depression risk when both concordant and discordant variants were considered, and nearly all depression risk variants influenced educational attainment. Additionally, depression genetic risk was associated with impaired complex cognition domains. We dissected the genetic and clinical heterogeneity, revealing distinct polygenic architectures across subgroups of depression and demonstrating significantly increased absolute risks for recurrence and psychiatric comorbidity among cases of depression with the highest polygenic burden, with considerable sex differences. The risks were up to 5- and 32-fold higher than cases with the lowest polygenic burden and the background population, respectively. These results deepen the understanding of the biology underlying depression, its disease progression and inform precision medicine approaches to treatment. A genome-wide meta-analysis of data from six US and European cohorts involving 1.3 million individuals identifies 243 genetic variants associated with risk and pathophysiology of depression, which is used to develop polygenic risk scores for the prediction of depression recurrence and comorbid psychiatric disorders.

We report high-precision Mg isotopic analyses of different types of lunar samples including two pristine Mg-suite rocks (72415 and 76535), basalts, anorthosites, breccias, mineral separates, and lunar meteorites. The Mg isotopic composition of the dunite 72415 (δ25Mg = −0.140 ± 0.010‰, δ26Mg = −0.291 ± 0.018‰), the most Mg-rich and possibly the oldest lunar sample, may provide the best estimate of the Mg isotopic composition of the bulk silicate Moon (BSM). This δ26Mg value of the Moon is similar to those of the Earth and chondrites and reflects both the relative homogeneity of Mg isotopes in the solar system and the lack of Mg isotope fractionation by the Moon-forming giant impact. In contrast to the behavior of Mg isotopes in terrestrial basalts and mantle rocks, Mg isotopic data on lunar samples show isotopic variations among the basalts and pristine anorthositic rocks reflecting isotopic fractionation during the early lunar magma ocean (LMO) differentiation. Calculated evolutions of δ26Mg values during the LMO differentiation are consistent with the observed δ26Mg variations in lunar samples, implying that Mg isotope variations in lunar basalts are consistent with their origin by remelting of distinct LMO cumulates.

Posttraumatic stress disorder (PTSD) is a common, frequently chronic, and disabling condition which, along with acute stress disorder (ASD), is categorized as a trauma- and stressor-related disorder by the DSM-5. These disorders are unique in requiring exposure to a severe stressor, which implies that potential sufferers could be identified and helped before developing a disorder. Research on prevention strategies for stress-related disorders has taken a number of avenues, including intervention before and after trauma and the use of both psychosocial and somatic approaches. Despite advances in neurobiological understanding of response to trauma, clinical evidence for preventive interventions remains sparse. This review provides an overview of prevention approaches and summarizes the existing literature on prevention of ASD and PTSD, including clinical and preclinical studies. Given the potential benefits to trauma survivors and society, the development of effective preventive interventions should be given greater priority. Resources should be directed to adequately test promising interventions in clinical trials, and research should be conducted according to translational research principles in which preclinical research informs the design of clinical studies.