RESUMO
As native ranges are often geographically structured, invasive species originating from a single source population only carry a fraction of the genetic diversity present in their native range. The invasion process is thus often associated with a drastic loss of genetic diversity resulting from a founder event. However, the fraction of diversity brought to the invasive range may vary under different invasion histories, increasing with the size of the propagule, the number of reintroduction events, and/or the total genetic diversity represented by the various source populations in a multiple-introduction scenario. In this study, we generated a SNP data set for the invasive termite Reticulitermes flavipes from 23 native populations in the eastern United States and six introduced populations throughout the world. Using population genetic analyses and approximate Bayesian computation random forest, we investigated its worldwide invasion history. We found a complex invasion pathway with multiple events out of the native range and bridgehead introductions from the introduced population in France. Our data suggest that extensive long-distance jump dispersal appears common in both the native and introduced ranges of this species, probably through human transportation. Overall, our results show that similar to multiple introduction events into the invasive range, admixture in the native range prior to invasion can potentially favour invasion success by increasing the genetic diversity that is later transferred to the introduced range.
Assuntos
Genética Populacional , Espécies Introduzidas , Isópteros , Animais , Teorema de Bayes , Variação Genética , Isópteros/genética , Repetições de Microssatélites , Estados UnidosRESUMO
The microbes residing within the gut of an animal host often increase their own fitness by modifying their host's physiological, reproductive and behavioural functions. Whereas recent studies suggest that they may also shape host sociality and therefore have critical effects on animal social evolution, the impact of the gut microbiota on maternal care remains unexplored. This is surprising, as this behaviour is widespread among animals, often determines the fitness of both juveniles and parents, and is essential in the evolution of complex animal societies. Here, we tested whether life-long alterations of the gut microbiota with rifampicin-a broad-spectrum antibiotic-impair pre- and post-hatching maternal care in the European earwig. Our results first confirm that rifampicin altered the mothers' gut microbial communities and indicate that the composition of the gut microbiota differs before and after egg care. Contrary to our predictions, however, the rifampicin-induced alterations of the gut microbiota did not modify pre- or post-hatching care. Independent of maternal care, rifampicin increased the females' faeces production and resulted in lighter eggs and juveniles. By contrast, rifampicin altered none of the other 21 physiological, reproductive and longevity traits measured over the 300 days of a female's lifetime. Overall, these findings reveal that altering the gut microbiota with a large spectrum antibiotic such as rifampicin does not necessarily affect host sociality. They also emphasize that not all animals have evolved a co-dependence with their microbiota and call for caution when generalizing the central role of gut microbes in host biology.
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Microbioma Gastrointestinal , Microbiota , Animais , Antibacterianos , Feminino , Rifampina , Comportamento SocialRESUMO
Although mutualistic associations between animals and microbial symbionts are widespread in nature, the mechanisms that have promoted their evolutionary persistence remain poorly understood. A vertical mode of symbiont transmission (from parents to offspring) is thought to ensure partner fidelity and stabilization, although the efficiency of vertical transmission has rarely been investigated, especially in cases where hosts harbour a diverse microbial community. Here we evaluated vertical transmission rates of cellulolytic gut oxymonad and parabasalid protists in the wood-feeding termite Reticulitermes grassei. We sequenced amplicons of the 18S rRNA gene of protists from 24 colonies of R. grassei collected in two populations. For each colony, the protist community was characterized from the gut of 14 swarming reproductives and from a pool of 10 worker guts. A total of 98 operational taxonomic units belonging to 13 species-level taxa were found. The vertical transmission rate was estimated for each protist present in a colony based on its frequency among the reproductives. The results revealed that transmission rates were high, with an average of 0.897 (±0.164) per protist species. Overall, the protist community did not differ between reproductive sexes, suggesting that both the queen and the king could contribute to the gut microbiota of the offspring. A positive relationship between the transmission rate of protists and their prevalence within populations was also detected. However, transmission rates alone do not explain the prevalence of protists. In conclusion, these findings reveal key forces behind a conserved, multispecies mutualism, raising further questions on the roles of horizontal transfer and negative selection in shaping symbiont prevalence.
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Metagenômica/métodos , Transcriptoma/genética , Código de Barras de DNA Taxonômico/métodos , Ecologia , Oceano Pacífico , Fitoplâncton/genética , Proteostase/genética , Proteostase/fisiologiaRESUMO
The creation of geographic barriers has long been suspected to contribute to the formation of new species. We investigated the phylogeography of desert ants in the western Mediterranean basin in order to elucidate their mode of diversification. These insects which have a low dispersal capacity are recently becoming important model systems in evolutionary studies. We conducted an extensive sampling of species belonging to the Cataglyphis albicans group in the Iberian Peninsula (IP) and the northern Morocco (North Africa; NA). We then combined genetic, chemical and morphological analyses. The results suggest the existence of at least three and five clades in the IP and NA, respectively, whose delineation partially encompass current taxonomic classification. The three Iberian clades are monophyletic, but their origin in NA is uncertain (79% and 22% for Bayesian and Maximum Likelihood support, respectively). The estimation of divergence time suggests that a speciation process was initiated after the last reopening of the Gibraltar Straits ≈5.33 Ma. In the IP, the clades are parapatric and their formation may have been triggered by the fragmentation of a large population during the Pleistocene due to extended periods of glaciation. This scenario is supported by demographic analyses pointing at a recent expansion of Iberian populations that contrasts with the progressive contraction of the NA clades. Niche modeling reveals that this area, governed by favorable climatic conditions for desert ants, has recently increased in the IP and decreased in NA. Altogether, our data points at geoclimatic events as major determinants of species formation in desert ants, reinforcing the role of allopatric speciation.
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Formigas/fisiologia , Evolução Biológica , África do Norte , Animais , Formigas/anatomia & histologia , Formigas/genética , Teorema de Bayes , Demografia , Análise Discriminante , Europa (Continente) , Variação Genética , Gibraltar , Hidrocarbonetos/metabolismo , Funções Verossimilhança , Masculino , Repetições de Microssatélites/genética , Modelos Biológicos , Marrocos , Filogenia , Filogeografia , Análise de Componente PrincipalRESUMO
Termites of the genus Reticulitermes are widespread invaders, particularly in urban habitats. Their cryptic and subterranean lifestyle makes them difficult to detect, and we know little about their colony dynamics over time. In this study we examined the persistence of Reticulitermes flavipes (Kollar) colonies in the city of Paris over a period of 15 years. The aim was (1) to define the boundaries of colonies sampled within the same four areas over two sampling periods, (2) to determine whether the colonies identified during the first sampling period persisted to the second sampling period, and (3) to compare the results obtained when colonies were delineated using a standard population genetic approach versus a Bayesian clustering method that combined both spatial and genetic information. Herein, colony delineations were inferred from genetic differences at nine microsatellite loci and one mitochondrial locus. Four of the 18 identified colonies did not show significant differences in their genotype distributions between the two sampling periods. While allelic richness was low, making it hard to reliably distinguish colony family type, most colonies appeared to retain the same breeding structure over time. These large and expansive colonies showed an important ability to fuse (39% were mixed-family colonies), contained hundreds of reproductives and displayed evidence of isolation-by-distance, suggesting budding dispersal. These traits, which favor colony persistence over time, present a challenge for pest control efforts, which apply treatment locally. The other colonies showed significant differences, but we cannot exclude the possibility that their genotype distributions simply changed over time.
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Isópteros/crescimento & desenvolvimento , Animais , Teorema de Bayes , Cruzamento , Ecossistema , Variação Genética , Genética Populacional , Isópteros/classificação , Isópteros/genética , ParisRESUMO
Termites of the genus Reticulitermes are ecologically and economically important wood-feeding social insects that are widespread in the Holarctic region. Despite their importance, no study has yet attempted to reconstruct a global time-scaled phylogeny of Reticulitermes termites. In this study, we sequenced mitochondrial (2096bp) and nuclear (829bp) loci from 61 Reticulitermes specimens, collected across the genus' entire range, and one specimen of Coptotermes formosanus, which served as an outgroup. Bayesian and Maximum likelihood analyses conducted on the mitochondrial and nuclear sequences support the existence of four main lineages that span four global geographical regions: North America (NA lineage), western Europe (WE lineage), a region including eastern Europe and western Asia (EA+WA lineage), and eastern Asia (EA lineage). The mitochondrial data allowed us to clarify the phylogenetic relationships among these lineages. They were also used to infer a chronogram that was time scaled based on age estimates for termite fossils (including the oldest Reticulitermes fossils, which date back to the late Eocene-early Oligocene). Our results support the hypothesis that the extant Reticulitermes lineage first differentiated in North America. The first divergence event in the ancestral lineage of Reticulitermes occurred in the early Miocene and separated the Nearctic lineages (i.e., the NA lineages) from the Palearctic lineages (i.e., WE, EE+WA, and EA lineages). Our analyses revealed that the main lineages of Reticulitermes diversified because of vicariance and migration events, which were probably induced by major paleogeographic and paleoclimatic changes that occurred during the Cenozoic era. This is the first global and comprehensive phylogenetic study of Reticulitermes termites, and it provides a crucial foundation for studying the evolution of phenotypic and life-history traits in Reticulitermes. For instance, the phylogeny we obtained suggested that 'asexual queen succession', a unique reproductive system, independently evolved at least three times during the diversification of the genus.
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Isópteros/classificação , Animais , Evolução Biológica , Núcleo Celular , DNA Mitocondrial , Genes de Insetos , Especiação Genética , Isópteros/genética , Filogenia , FilogeografiaRESUMO
BACKGROUND: Health anxiety has been treated by therapists expert in cognitive behaviour therapy with some specific benefit in some patients referred to psychological services. Those in hospital care have been less often investigated. Following a pilot trial suggesting efficacy we carried out a randomised study in hospital medical clinics. METHODS: We undertook a multicentre, randomised trial on health anxious patients attending cardiac, endocrine, gastroenterological, neurological, and respiratory medicine clinics in secondary care. We included those aged 16-75 years, who satisfied the criteria for excessive health anxiety, and were resident in the area covered by the hospital, were not under investigation for new pathology or too medically unwell to take part. We used a computer-generated random scheme to allocate eligible medical patients to an active treatment group of five-to-ten sessions of adapted cognitive behaviour therapy (CBT-HA group) delivered by hospital-based therapists or to standard care in the clinics. The primary outcome was change in health anxiety symptoms measured by the Health Anxiety Inventory at 1 year and the main secondary hypothesis was equivalence of total health and social care costs over 2 years, with an equivalence margin of £150. Analysis was by intention to treat. The study is registered with controlled-trials.com, ISRCTN14565822. FINDINGS: Of 28,991 patients screened, 444 were randomly assigned to receive either adapted cognitive behaviour therapy (CBT-HA group, 219 participants) or standard care (standard care group, 225), with 205 participants in the CBT-HA group and 212 in the standard care group included in the analyses of the primary endpoints. At 1 year, improvement in health anxiety in the patients in the CBT-HA group was 2·98 points greater than in those in the standard care group (95% CI 1·64-4·33, p<0·0001), and twice as many patients receiving cognitive behaviour therapy achieved normal levels of health anxiety compared with those in the control group (13·9% vs 7·3%; odds ratio 2·15, 95% CI 1·09-4·23, p=0·0273). Similar differences were observed at 6 months and 2 years, and there were concomitant reductions in generalised anxiety and, to a lesser extent, depression. Of nine deaths, six were in the control group; all were due to pre-existing illness. Social functioning or health-related quality of life did not differ significantly between groups. Equivalence in total 2-year costs was not achieved, but the difference was not significant (adjusted mean difference £156, 95% CI -1446 to 1758, p=0·848). INTERPRETATION: This form of adapted cognitive behaviour therapy for health anxiety led to sustained symptomatic benefit over 2 years, with no significant effect on total costs. It deserves wider application in medical care. FUNDING: National Institute for Health Research Health Technology Assessment Programme.
Assuntos
Terapia Cognitivo-Comportamental/métodos , Custos de Cuidados de Saúde/estatística & dados numéricos , Hipocondríase/terapia , Adolescente , Adulto , Idoso , Transtornos de Ansiedade/economia , Transtornos de Ansiedade/terapia , Terapia Cognitivo-Comportamental/economia , Análise Custo-Benefício , Manual Diagnóstico e Estatístico de Transtornos Mentais , Inglaterra , Feminino , Humanos , Hipocondríase/economia , Masculino , Pessoa de Meia-Idade , Ambulatório Hospitalar/economia , Psicometria , Qualidade de Vida , Método Simples-Cego , Resultado do Tratamento , Adulto JovemRESUMO
Nestmate recognition is a common phenomenon in social insects that typically is mediated by cuticular hydrocarbons. Geographical variation in cuticular hydrocarbons has been observed, although the pattern of variation is not consistent across species and is usually related to the biology and ecology of the different species. Polistes biglumis (Hymenoptera: Vespidae) is a social wasp that lives in high mountains where populations are separated by significant geographical barriers. Here we investigated the level of chemical variation among populations of P. biglumis in the Alps, and shed light on the phylogeography of this species. Populations could be discriminated by means of their cuticular hydrocarbon profiles, which showed a pattern consistent with the isolation-by-distance hypothesis. Molecular data highlighted two areas with different levels of haplotype diversity, although all wasps belonged to the same species. These results suggest that the populations of P. biglumis in the Alps are geographically isolated from one another, favoring their genetic and chemical differentiation.
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DNA Mitocondrial , Hidrocarbonetos/química , Filogenia , Vespas/química , Vespas/genética , Animais , Comportamento Animal , França , Variação Genética , Genética Populacional , Haplótipos , Itália , Dados de Sequência Molecular , Filogeografia , SuíçaRESUMO
Invasive species cause severe environmental and economic problems. The invasive success of social insects often appears to be related to their ability to adjust their social organization to new environments. To gain a better understanding of the biology of invasive termites, this study investigated the social organization of the subterranean termite, Reticulitermes urbis, analyzing the breeding structure and the number of reproductives within colonies from three introduced populations. By using eight microsatellite loci to determine the genetic structure, it was found that all the colonies from the three populations were headed by both primary reproductives (kings and queens) and secondary reproductives (neotenics) to form extended-family colonies. R. urbis appears to be the only Reticulitermes species with a social organization based solely on extended-families in both native and introduced populations, suggesting that there is no change in their social organization on introduction. F-statistics indicated that there were few neotenics within the colonies from urban areas, which did not agree with results from previous studies and field observations. This suggests that although several neotenics may be produced, only few become active reproductives. The results also imply that the invasive success of R. urbis may be based on different reproductive strategies in urban and semiurbanized areas. The factors influencing an individual to differentiate into a neotenic in Reticulitermes species are discussed.
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Isópteros/genética , Repetições de Microssatélites , Animais , Feminino , França , Genótipo , Espécies Introduzidas , Isópteros/fisiologia , Itália , Masculino , Reação em Cadeia da Polimerase , Dinâmica Populacional , ReproduçãoRESUMO
BACKGROUND: Abnormal health anxiety, also called hypochondriasis, has been successfully treated by cognitive behaviour therapy (CBT) in patients recruited from primary care, but only one pilot trial has been carried out among those attending secondary medical clinics where health anxiety is likely to be more common and have a greater impact on services. The CHAMP study extends this work to examine both the clinical and cost effectiveness of CBT in this population. METHOD/DESIGN: The study is a randomized controlled trial with two parallel arms and equal randomization of 466 eligible patients (assuming a 20% drop-out) to an active treatment group of 5-10 sessions of cognitive behaviour therapy and to a control group. The aim at baseline, after completion of all assessments but before randomization, was to give a standard simple explanation of the nature of health anxiety for all participants. Subsequently the control group was to receive whatever care might usually be available in the clinics, which is normally a combination of clinical assessment, appropriate tests and reassurance. Those allocated to the active treatment group were planned to receive between 5 and 10 sessions of an adapted form of cognitive behaviour therapy based on the Salkovskis/Warwick model, in which a set of treatment strategies are chosen aimed at helping patients understand the factors that drive and maintain health anxiety. The therapy was planned to be given by graduate research workers, nurses or other health professionals trained for this intervention whom would also have their competence assessed independently during the course of treatment. The primary outcome is reduction in health anxiety symptoms after one year and the main secondary outcome is the cost of care after two years. DISCUSSION: This represents the first trial of adapted cognitive behaviour therapy in health anxiety that is large enough to test not only the clinical benefits of treatment but also whether the cost of treatment is offset by savings from reduced use of other health services in comparison to the control group.Cognitive behaviour therapy for Health Anxiety in Medical Patients (CHAMP) TRIAL REGISTRATION: Current Controlled Trials ISRCTN14565822.
Assuntos
Terapia Cognitivo-Comportamental/estatística & dados numéricos , Hipocondríase/terapia , Adolescente , Adulto , Idoso , Protocolos Clínicos , Terapia Cognitivo-Comportamental/métodos , Análise Custo-Benefício/estatística & dados numéricos , Feminino , Custos de Cuidados de Saúde/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Determinação da Personalidade/estatística & dados numéricosRESUMO
Non-pharmacological breathlessness interventions in lung cancer have proven beneficial. Breathlessness is also a major symptom in chronic obstructive pulmonary disease (COPD). This study measured the effectiveness of a non-exercise-based four-week cognitive-behavioural breathlessness intervention, delivered in a group setting for elderly patients with severe COPD. The results of the one-year feasibility study are presented. Patients with COPD were asked to complete the St. George's Respiratory Questionnaire and Hospital Anxiety and Depression Scale six weeks before the intervention, at the start and end of the intervention and at six weeks follow-up. The multidisciplinary intervention used a cognitive-behavioural format to address understanding of COPD and medication, anxiety, panic and depression, activity pacing, relaxation, breathing retraining and goal-setting. Retrospective data on accident & emergency (A&E) attendances and length of hospital stay was collected six months before and six months after the intervention and the data compared to a matched waiting list control group. The results showed significant improvements in depression and health status. There was a non-significant improvement in anxiety. There was a significant reduction in A&E attendance and a non-significant reduction in length of hospital stay in the intervention group, compared to comparative increases in the control group, highlighting the cost-effectiveness of the intervention.
Assuntos
Afeto , Dispneia , Nível de Saúde , Admissão do Paciente , Psicoterapia de Grupo/métodos , Doença Pulmonar Obstrutiva Crônica/psicologia , Idoso , Idoso de 80 Anos ou mais , Ansiedade , Depressão , Feminino , Humanos , Londres , Masculino , Pessoa de Meia-Idade , Admissão do Paciente/tendências , Avaliação de Programas e Projetos de Saúde , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Estudos Retrospectivos , Inquéritos e QuestionáriosRESUMO
The co-evolutionary pathways followed by hosts and parasites strongly depend on the adaptive potential of antagonists and its underlying genetic architecture. Geographically structured populations of interacting species often experience local differences in the strength of reciprocal selection pressures, which can result in a geographic mosaic of co-evolution. One example of such a system is the boreo-montane social wasp Polistes biglumis and its social parasite Polistes atrimandibularis, which have evolved local defense and counter-defense mechanisms to match their antagonist. In this work, we study spatial genetic structure of P. biglumis and P. atrimandibularis populations at local and regional scales in the Alps, by using nuclear markers (DNA microsatellites, AFLP) and mitochondrial sequences. Both the host and the parasite populations harbored similar amounts of genetic variation. Host populations were not genetically structured at the local scale, but geographic regions were significantly differentiated from each other in both the host and the parasite in all markers. The net dispersal inferred from genetic differentiation was similar in the host and the parasite, which may be due to the annual migration pattern of the parasites between alpine and lowland populations. Thus, the apparent dispersal barriers (i.e., high mountains) do not restrict gene flow as expected and there are no important gene flow differences between the species, which contradict the hypothesis that restricted gene flow is required for local adaptations to evolve.
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Parental care is a major component of reproduction in social organisms, particularly during the foundation steps. Because investment into parental care is often costly, each parent is predicted to maximize its fitness by providing less care than its partner. However, this sexual conflict is expected to be low in species with lifelong monogamy, because the fitness of each parent is typically tied to the other's input. Somewhat surprisingly, the outcomes of this tug-of-war between maternal and paternal investments have received important attention in vertebrate species, but remain less known in invertebrates. In this study, we investigated how queens and kings share their investment into parental care and other social interactions during colony foundation in two termites with lifelong monogamy: the invasive species Reticulitermes flavipes and the native species R. grassei. Behaviors of royal pairs were recorded during six months using a non-invasive approach. Our results showed that queens and kings exhibit unbalanced investment in terms of grooming, antennation, trophallaxis, and vibration behavior. Moreover, both parents show behavioral differences toward their partner or their descendants. Our results also revealed differences among species, with R. flavipes exhibiting shorter periods of grooming and antennation toward eggs or partners. They also did more stomodeal trophallaxis and less vibration behavior. Overall, this study emphasizes that despite lifelong monogamy, the two parents are not equally involved in the measured forms of parental care and suggests that kings might be specialized in other tasks. It also indicates that males could play a central, yet poorly studied role in the evolution and maintenance of the eusocial organization.
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Termites are social insects that can also be major pests. A well-known problem species is the subterranean termite, Reticulitermes flavipes. It is invasive in France and is thought to have arrived from Louisiana during the 18th century. While the putative source of French populations has been identified, little is known about how the termite spread following its establishment. Here, we examined expansion patterns at different spatial scales in urban areas to clarify how R. flavipes spread in France. Based on our analyses of phylogeography and population genetics, results suggest a scenario of successive introductions into the Charente-Maritime region, on the Atlantic Coast. Two major expansion fronts formed: one that spread toward the northeast and the other toward the southeast. At the regional scale, different spatial and genetic distribution patterns were observed: there was heterogeneity in Île-de-France and aggregation in Centre-Val de Loire. At the local scale, we found that our three focal urban sites each formed a single large colony that contained several secondary reproductives. Our findings represent a second step in efforts to reconstruct termite's invasion dynamics. They also highlight the role that may have been played by the French railway network in transporting termites over long distances.
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BACKGROUND: Although much research has been carried out into European Reticulitermes taxonomy in recent years, there is still much discussion about phylogenetic relationships. This study investigated the evolution from intra- to interspecific phylogeny in the island subspecies Reticulitermes lucifugus corsicus and threw new light on this phenomenon. An integrative approach based on microsatellites and mitochondrial and nuclear DNA sequences was used to analyze samples taken from a wide area around the Tyrrhenian sea and showed how the subspecies evolved from its origins to its most recent form on continental coasts. RESULTS: According to mitochondrial phylogeny and molecular clock calculations, island and continental taxa diverged significantly by vicariance in the Pleistocene glacial period. However, more recently, numerous migrations, certainly human-mediated, affected the structure of the populations. This study provided evidence of direct hybridization and multiple introgressions which occurred in several hybrid areas. Analysis using STRUCTURE based on microsatellite data identified a population in Provence (France) which differed considerably (Fst = 0.477) from populations on the island of Corsica and in Tuscany in the Italian peninsula. This new population, principally distributed in urban areas, is highly heterogeneous especially within the ITS2 regions where homogenization by concerted evolution does not appear to have been completed. CONCLUSION: This study provides an unusual picture of genetic interaction between termite populations in the Tyrrhenian area and suggests that more attention should be paid to the role of introgression and human impact on the recent evolution of European termites.
Assuntos
Especiação Genética , Genoma de Inseto , Hibridização Genética , Isópteros/genética , Filogenia , Animais , Evolução Molecular , Análise Fatorial , Geografia , Haplótipos , Isópteros/classificação , Itália , Repetições de Microssatélites , Análise de Sequência de DNARESUMO
PURPOSE: A 4-week Pain Coping Strategies (PCS) programme has been developed for chronic pain patients who may still be undergoing medical interventions but who would benefit from learning pain management skills. The long-term negative behaviours associated with chronic pain may be prevented by introducing pain management strategies at an earlier stage. The PCS programme combines all the fundamental aspects of the traditional Pain Management Programme including exercise, relaxation, pacing, medication review, pain pathways, posture and challenging negative thoughts. METHOD: The study compared 31 patients' mood, functional status and physical ability pre and 6 weeks post the programme using the Hospital Anxiety and Depression Scale (HAD), Canadian Occupational Performance Measure (COPM) and a series of physical tests. A paired samples t-test showed a significant improvement in levels of depression and anxiety, functional status and physical ability. RESULTS: The results reveal that an early intervention programme may be effective for chronic pain patients by promoting self-management and teaching positive coping strategies. CONCLUSIONS: The current study has found promising results for a brief early intervention for chronic pain, regardless of completion of medical interventions.
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Adaptação Psicológica , Manejo da Dor , Adulto , Afeto , Idoso , Doença Crônica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dor/psicologia , Projetos Piloto , Resultado do TratamentoRESUMO
BACKGROUND: Health anxiety is an under-recognised but frequent cause of distress that is potentially treatable, but there are few studies in secondary care. OBJECTIVE: To determine the clinical effectiveness and cost-effectiveness of a modified form of cognitive-behaviour therapy (CBT) for health anxiety (CBT-HA) compared with standard care in medical outpatients. DESIGN: Randomised controlled trial. SETTING: Five general hospitals in London, Middlesex and Nottinghamshire. PARTICIPANTS: A total of 444 patients aged 16-75 years seen in cardiology, endocrinology, gastroenterology, neurology and respiratory medicine clinics who scored ≥ 20 points on the Health Anxiety Inventory (HAI) and satisfied diagnostic requirements for hypochondriasis. Those with current psychiatric disorders were excluded, but those with concurrent medical illnesses were not. INTERVENTIONS: Cognitive-behaviour therapy for health anxiety - between 4 and 10 1-hour sessions of CBT-HA from a health professional or psychologist trained in the treatment. Standard care was normal practice in primary and secondary care. MAIN OUTCOME MEASURES: Primary - researchers masked to allocation assessed patients at baseline, 3, 6, 12, 24 months and 5 years. The primary outcome was change in the HAI score between baseline and 12 months. Main secondary outcomes - costs of care in the two groups after 24 and 60 months, change in health anxiety (HAI), generalised anxiety and depression [Hospital Anxiety and Depression Scale (HADS)] scores, social functioning using the Social Functioning Questionnaire and quality of life using the EuroQol-5 Dimensions (EQ-5D), at 6, 12, 24 and 60 months, and deaths over 5 years. RESULTS: Of the 28,991 patients screened over 21 months, 5769 had HAI scores of ≥ 20 points. Improvement in HAI scores at 3 months was significantly greater in the CBT-HA group (mean number of sessions = 6) than in the standard care, and this was maintained over the 5-year period (overall p < 0.0001), with no loss of efficacy between 2 and 5 years. Differences in the generalised anxiety (p = 0.0018) and depression scores (p = 0.0065) on the HADS were similar in both groups over the 5-year period. Gastroenterology and cardiology patients showed the greatest CBT gains. The outcomes for nurses were superior to those of other therapists. Deaths (n = 24) were similar in both groups; those in standard care died earlier than those in CBT-HA. Patients with mild personality disturbance and higher dependence levels had the best outcome with CBT-HA. Total costs were similar in both groups over the 5-year period (£12,590.58 for CBT-HA; £13,334.94 for standard care). CBT-HA was not cost-effective in terms of quality-adjusted life-years, as measured using the EQ-5D, but was cost-effective in terms of HAI outcomes, and offset the cost of treatment. LIMITATIONS: Many eligible patients were not randomised and the population treated may not be representative. CONCLUSIONS: CBT-HA is a highly effective treatment for pathological health anxiety with lasting benefit over 5 years. It also improves generalised anxiety and depressive symptoms more than standard care. The presence of personality abnormality is not a bar to successful outcome. CBT-HA may also be cost-effective, but the high costs of concurrent medical illnesses obscure potential savings. This treatment deserves further research in medical settings. TRIAL REGISTRATION: Current Controlled Trials ISRCTN14565822. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 50. See the NIHR Journals Library website for further project information.
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Ansiedade/terapia , Terapia Cognitivo-Comportamental/métodos , Hipocondríase/terapia , Adolescente , Adulto , Idoso , Instituições de Assistência Ambulatorial , Escalas de Graduação Psiquiátrica Breve , Terapia Cognitivo-Comportamental/economia , Análise Custo-Benefício , Feminino , Humanos , Hipocondríase/economia , Estudos Longitudinais , Masculino , Resultado do TratamentoRESUMO
OBJECTIVES: To identify the extent and nature of functional somatic symptoms (FSS) in a UK Accident and Emergency (A&E) Department. METHODS: A mixed method design was used. Data on the number and outcomes of attendances of patients who had attended A&E four or more times in a 6-month period, and who had not received a medical diagnosis were collected. Levels of anxiety and depression were explored and patients were invited to attend an interview with a clinical psychologist. RESULTS: One hundred frequent attendees made 595 visits to A&E in 6 months, with 20% of visits resulting in a hospital admission. Participants revealed high levels of health anxiety, with over half of participants reporting a perceived link between psychological factors and their experience of symptoms. Over 80% of participants attending the interview wanted further help to manage their symptoms and health care utilisation. CONCLUSIONS: Functional somatic symptoms are highly distressing for patients and place high demands on health care resources. An alternative care pathway to assess and manage FSS in A&E may need to be developed to help patients to manage their health anxiety.
Assuntos
Serviço Hospitalar de Emergência/estatística & dados numéricos , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Transtornos Somatoformes/psicologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Ansiedade/complicações , Depressão/complicações , Serviços de Emergência Psiquiátrica , Feminino , Necessidades e Demandas de Serviços de Saúde , Pesquisa sobre Serviços de Saúde , Hospitais Gerais/estatística & dados numéricos , Humanos , Londres , Masculino , Pessoa de Meia-Idade , Pesquisa Metodológica em Enfermagem , Avaliação de Resultados em Cuidados de Saúde , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Admissão do Paciente/estatística & dados numéricos , Escalas de Graduação Psiquiátrica , Fatores de Risco , Autoavaliação (Psicologia) , Transtornos Somatoformes/diagnóstico , Transtornos Somatoformes/etiologia , Transtornos Somatoformes/terapia , Inquéritos e QuestionáriosRESUMO
A long-standing goal of evolutionary biology is to understand how paleoclimatic and geological events shape the geographical distribution and genetic structure within and among species. Using a diverse set of markers (cuticular hydrocarbons, mitochondrial and nuclear gene sequences, microsatellite loci), we studied Reticulitermes grassei and R. banyulensis, two closely related termite species in southwestern Europe. We sought to clarify the current genetic structure of populations that formed following postglacial dispersal from refugia in southern Spain and characterize the gene flow between the two lineages over the last several million years. Each marker type separately provided a fragmented picture of the evolutionary history at different timescales. Chemical analyses of cuticular hydrocarbons and phylogenetic analyses of mitochondrial and nuclear genes showed clear separation between the species, suggesting they diverged following vicariance events in the Late Miocene. However, the presence of intermediate chemical profiles and mtDNA introgression in some Spanish colonies suggests ongoing gene flow. The current genetic structure of Iberian populations is consistent with alternating isolation and dispersal events during Quaternary glacial periods. Analyses of population genetic structure revealed postglacial colonization routes from southern Spain to France, where populations underwent strong genetic bottlenecks after traversing the Pyrenees resulting in parapatric speciation.