Observation of inverse Compton emission from a long γ-ray burst.

Long-duration γ-ray bursts (GRBs) originate from ultra-relativistic jets launched from the collapsing cores of dying massive stars. They are characterized by an initial phase of bright and highly variable radiation in the kiloelectronvolt-to-megaelectronvolt band, which is probably produced within the jet and lasts from milliseconds to minutes, known as the prompt emission1,2. Subsequently, the interaction of the jet with the surrounding medium generates shock waves that are responsible for the afterglow emission, which lasts from days to months and occurs over a broad energy range from the radio to the gigaelectronvolt bands1-6. The afterglow emission is generally well explained as synchrotron radiation emitted by electrons accelerated by the external shock7-9. Recently, intense long-lasting emission between 0.2 and 1 teraelectronvolts was observed from GRB 190114C10,11. Here we report multi-frequency observations of GRB 190114C, and study the evolution in time of the GRB emission across 17 orders of magnitude in energy, from 5 × 10-6 to 1012 electronvolts. We find that the broadband spectral energy distribution is double-peaked, with the teraelectronvolt emission constituting a distinct spectral component with power comparable to the synchrotron component. This component is associated with the afterglow and is satisfactorily explained by inverse Compton up-scattering of synchrotron photons by high-energy electrons. We find that the conditions required to account for the observed teraelectronvolt component are typical for GRBs, supporting the possibility that inverse Compton emission is commonly produced in GRBs.

Very-high-energy particle acceleration powered by the jets of the microquasar SS 433.

SS 433 is a binary system containing a supergiant star that is overflowing its Roche lobe with matter accreting onto a compact object (either a black hole or neutron star)1-3. Two jets of ionized matter with a bulk velocity of approximately 0.26c (where c is the speed of light in vacuum) extend from the binary, perpendicular to the line of sight, and terminate inside W50, a supernova remnant that is being distorted by the jets2,4-8. SS 433 differs from other microquasars (small-scale versions of quasars that are present within our own Galaxy) in that the accretion is believed to be super-Eddington9-11, and the luminosity of the system is about 1040 ergs per second2,9,12,13. The lobes of W50 in which the jets terminate, about 40 parsecs from the central source, are expected to accelerate charged particles, and indeed radio and X-ray emission consistent with electron synchrotron emission in a magnetic field have been observed14-16. At higher energies (greater than 100 gigaelectronvolts), the particle fluxes of γ-rays from X-ray hotspots around SS 433 have been reported as flux upper limits6,17-20. In this energy regime, it has been unclear whether the emission is dominated by electrons that are interacting with photons from the cosmic microwave background through inverse-Compton scattering or by protons that are interacting with the ambient gas. Here we report teraelectronvolt γ-ray observations of the SS 433/W50 system that spatially resolve the lobes. The teraelectronvolt emission is localized to structures in the lobes, far from the centre of the system where the jets are formed. We have measured photon energies of at least 25 teraelectronvolts, and these are certainly not Doppler-boosted, because of the viewing geometry. We conclude that the emission-from radio to teraelectronvolt energies-is consistent with a single population of electrons with energies extending to at least hundreds of teraelectronvolts in a magnetic field of about 16 microgauss.

Publisher Correction: Very-high-energy particle acceleration powered by the jets of the microquasar SS 433.

In this Letter, owing to a production error, the penultimate version of the PDF was published. The HTML version was always correct. The PDF has been corrected online.

2023 Undetectable = Untransmittable global policy roundtable report: a multistakeholder perspective on Undetectable = Untransmittable research and policy priorities.

Background Launched in 2016 by Prevention Access Campaign, the 'Undetectable=Untransmittable' (U=U) campaign empowers people living with HIV to live full social, sexual and reproductive lives, dismantle stigma, promote increased treatment access, and advocate for updated HIV guidelines. Methods Key priorities for promoting improvements to community-centred, evidence-informed U=U policy and research were the focus of a half-day global roundtable held in 2023 alongside the 12th International AIDS Society Conference in Brisbane, Australia. After a series of presentations, experts in U=U research, policymaking, advocacy and HIV clinical care participated in facilitated discussions, and detailed notes were taken on issues related to advancing U=U policy and research. Results Expert participants shared that knowledge and trust in U=U remains uneven, and is largely concentrated among people living with HIV, particularly those connected to gay and bisexual networks. It was agreed that there is a need to ensure all members of priority populations are explicitly included in U=U policies that promote U=U. Participants also identified a need for policymakers, healthcare professionals, advocates and researchers to work closely with community-based organisations to ensure the U=U message is relevant, useful, and utilised in the HIV response. Adopting language, such as 'zero risk', was identified as crucial when describing undetectable viral load as an effective HIV prevention strategy. Conclusion U=U can have significant benefits for the mental and physical wellbeing of people living with HIV. There is an urgent need to address the structural barriers to HIV care and treatment access to ensure the full benefits of U=U are realised.

Natural History of Asymptomatic Moderate Carotid Artery Stenosis in a Large Community-Based Cohort.

BACKGROUND: Moderate carotid artery stenosis is a poorly defined risk factor for ischemic stroke. As such, practice recommendations are lacking. In this study, we describe the long-term risk of stroke in patients with moderate asymptomatic stenosis in an integrated health care system. METHODS: All adult patients with asymptomatic moderate (50%-69%) internal carotid artery stenosis between 2008 and 2012 were identified, with follow-up through 2017. The primary outcome was acute ischemic stroke attributed to the ipsilateral carotid artery. Stroke rates were calculated using competing risk analysis. Secondary outcomes included disease progression, ipsilateral intervention, and long-term survival. RESULTS: Overall, 11 614 arteries with moderate stenosis in 9803 patients were identified. Mean age was 74.2±9.9 years with 51.4% women. Mean follow-up was 5.1±2.9 years. There were 180 ipsilateral ischemic strokes (1.6%) identified (crude annual risk, 0.31% [95% CI, 0.21%-0.41%]), of which thirty-one (17.2%) underwent subsequent intervention. Controlling for death and intervention as competing risks, the cumulative incidence of stroke was 1.2% (95% CI, 1.0%-1.4%) at 5 years and 2.0% (95% CI, 1.7%-2.4%) at 10 years. Of identified strokes, 50 (27.8%) arteries had progressed to severe stenosis or occlusion. During follow-up, there were 17 029 carotid studies performed in 5951 patients, revealing stenosis progression in 1674 (14.4%) arteries, including 1614 (13.9%) progressing to severe stenosis and 60 (0.5%) to occlusion. The mean time to stenosis progression was 2.6±2.1 years. Carotid intervention occurred in 708 arteries (6.1%). Of these, 66.1% (468/708) had progressed to severe stenosis. The overall mortality rate was 44.5%, with 10.5% of patients lost to follow-up. CONCLUSIONS: In this community-based sample of patients with asymptomatic moderate internal carotid artery stenosis followed for an average of 5 years, the cumulative incidence of stroke is low out to 10 years. Future research is needed to optimize management strategies for this population.

Incidence of Ischemic Stroke in Patients With Asymptomatic Severe Carotid Stenosis Without Surgical Intervention.

Importance: Optimal management of patients with asymptomatic severe carotid stenosis is uncertain, due to advances in medical care and a lack of contemporary data comparing medical and surgical treatment. Objective: To estimate stroke outcomes among patients with medically treated asymptomatic severe carotid stenosis who did not undergo surgical intervention. Design, Setting, and Participants: Retrospective cohort study that included 3737 adult participants with asymptomatic severe (70%-99%) carotid stenosis diagnosed between 2008 and 2012 and no prior intervention or ipsilateral neurologic event in the prior 6 months. Participants received follow-up through 2019, and all were members of an integrated US regional health system serving 4.5 million members. Exposures: Imaging diagnosis of asymptomatic carotid stenosis of 70% to 99%. Main Outcomes and Measures: Occurrence of ipsilateral carotid-related acute ischemic stroke. Censoring occurred with death, disenrollment, or ipsilateral intervention. Results: Among 94 822 patients with qualifying imaging studies, 4230 arteries in 3737 (mean age, 73.8 [SD 9.5 years]; 57.4% male) patients met selection criteria including 2539 arteries in 2314 patients who never received intervention. The mean follow-up in this cohort was 4.1 years (SD 3.6 years). Prior to any intervention, there were 133 ipsilateral strokes with a mean annual stroke rate of 0.9% (95% confidence interval [CI], 0.7%-1.2%). The Kaplan-Meier estimate of ipsilateral stroke by 5 years was 4.7% (95% CI, 3.9%-5.7%). Conclusions and Relevance: In a community-based cohort of patients with asymptomatic severe carotid stenosis who did not undergo surgical intervention, the estimated rate of ipsilateral carotid-related acute ischemic stroke was 4.7% over 5 years. These findings may inform decision-making regarding surgical and medical treatment for patients with asymptomatic severe carotid artery stenosis.

Establishing a carotid artery stenosis disease cohort for comparative effectiveness research using natural language processing.

OBJECTIVE: Investigation of asymptomatic carotid stenosis treatment is hindered by the lack of a contemporary population-based disease cohort. We describe the use of natural language processing (NLP) to identify stenosis in patients undergoing carotid imaging. METHODS: Adult patients with carotid imaging between 2008 and 2012 in a large integrated health care system were identified and followed through 2017. An NLP process was developed to characterize carotid stenosis according to the Society of Radiologists in Ultrasound (for ultrasounds) and North American Symptomatic Carotid Endarterectomy Trial (NASCET) (for axial imaging) guidelines. The resulting algorithm assessed text descriptors to categorize normal/non-hemodynamically significant stenosis, moderate or severe stenosis as well as occlusion in both carotid ultrasound (US) and axial imaging (computed tomography and magnetic resonance angiography [CTA/MRA]). For US reports, internal carotid artery systolic and diastolic velocities and velocity ratios were assessed and matched for laterality to supplement accuracy. To validate the NLP algorithm, positive predictive value (PPV or precision) and sensitivity (recall) were calculated from simple random samples from the population of all imaging studies. Lastly, all non-normal studies were manually reviewed for confirmation for prevalence estimates and disease cohort assembly. RESULTS: A total of 95,896 qualifying index studies (76,276 US and 19,620 CTA/MRA) were identified among 94,822 patients including 1059 patients who underwent multiple studies on the same day. For studies of normal/non-hemodynamically significant stenosis arteries, the NLP algorithm showed excellent performance with a PPV of 99% for US and 96.5% for CTA/MRA. PPV/sensitivity to identify a non-normal artery with correct laterality in the CTA/MRA and US samples were 76.9% (95% confidence interval [CI], 74.1%-79.5%)/93.1% (95% CI, 91.1%-94.8%) and 74.7% (95% CI, 69.3%-79.5%)/94% (95% CI, 90.2%-96.7%), respectively. Regarding cohort assembly, 15,522 patients were identified with diseased carotid artery, including 2674 exhibiting equal bilateral disease. This resulted in a laterality-specific cohort with 12,828 moderate, 5283 severe, and 1895 occluded arteries and 326 diseased arteries with unknown stenosis. During follow-up, 30.1% of these patients underwent 61,107 additional studies. CONCLUSIONS: Use of NLP to detect carotid stenosis or occlusion can result in accurate exclusion of normal/non-hemodynamically significant stenosis disease states with more moderate precision with lesion identification, which can substantially reduce the need for manual review. The resulting cohort allows for efficient research and holds promise for similar reporting in other vascular diseases.

Long-term stroke risk with carotid endarterectomy in patients with severe carotid stenosis.

OBJECTIVE: Informed debate regarding the optimal use of carotid endarterectomy (CEA) for stroke risk reduction requires contemporary assessment of both long-term risk and periprocedural risk. In this study, we report long-term stroke and death risk after CEA in a large integrated health care system. METHODS: All patients with documented severe (70%-99%) stenosis from 2008 to 2012 who underwent CEA were identified and stratified by asymptomatic or symptomatic indication. Those with prior ipsilateral interventions were excluded. Patients were followed up through 2017 for the primary outcomes of any stroke/death within 30 days of intervention and long-term ipsilateral ischemic stroke; secondary outcomes were any stroke and overall survival. RESULTS: Overall, 1949 patients (63.2% male; mean age, 71.3 ± 8.9 years) underwent 2078 primary CEAs, 1196 (58%) for asymptomatic stenosis and 882 (42%) for symptomatic stenosis. Mean follow-up was 5.5 ± 2.7 years. Median time to surgery was 72.0 (interquartile range, 38.5-198.0) days for asymptomatic patients and 21.0 (interquartile range, 5.0-55.0) days for symptomatic patients (P < .001). Most of the patients' demographics and characteristics were similar in both groups. Controlled blood pressure rates were similar at the time of CEA. Baseline statin use was seen in 60.5% of the asymptomatic group compared with 39.9% in the symptomatic group (P < .001), and statin adherence by 80% medication possession ratio was 19.3% asymptomatic vs 12.4% symptomatic (P < .001). The crude overall 30-day any stroke/death rates were 0.9% and 1.5% for the asymptomatic group and the symptomatic group, respectively. The 5-year risk of ipsilateral stroke and a combined end point of any stroke/death by Kaplan-Meier survival analysis were 2.5% and 28.7% for the asymptomatic group and 4.0% and 31.4% for the symptomatic group, respectively. Unadjusted cumulative all-cause survival was 74.2% for the asymptomatic group and 71.8% for the symptomatic group at 5 years. CONCLUSIONS: In a contemporary review of CEA, outcomes for either operative indication show low adverse events perioperatively and low long-term stroke risk up to 5 years. These results are well within consensus guidelines and published trial outcomes and should help inform the discussion around optimal CEA use for severe carotid stenosis.

The effect of fo fall, downstep, and secondary cues in perceiving Japanese lexical accent.

Lexical pitch accent in Japanese is primarily realized as a steep fall in fo from an accented syllable into the following one. In addition, when a phrase that contains an accented syllable is followed by another phrase, the following phrase undergoes downstep, a compression of the fo range. Furthermore, while their acoustic identity is not yet clear, secondary cues to Japanese pitch accent are known to exist. The present study examined how speakers of Tokyo Japanese used acoustic information from these three sources in perceiving lexical pitch accent in Tokyo Japanese. Listeners heard stimuli in which the acoustic cues related to accent were independently manipulated and were asked to identify if a word presented sentence-medially was a final-accented word or its unaccented counterpart. Results found that listeners' judgments of words were most consistent with the presence or absence of downstep. That is, listeners identified that the preceding phrase contained an accented word when the following phrase was downstepped. Listeners also used the fo fall to determine if the word in question was a final-accented word or an unaccented word. Secondary cues to pitch accent were most weakly related to listeners' identification of accent.

Inter-relationships among psychopathology, premorbid adjustment, cognition and psychosocial functioning in first-episode psychosis: a network analysis approach.

BACKGROUND: Better understanding of interplay among symptoms, cognition and functioning in first-episode psychosis (FEP) is crucial to promoting functional recovery. Network analysis is a promising data-driven approach to elucidating complex interactions among psychopathological variables in psychosis, but has not been applied in FEP. METHOD: This study employed network analysis to examine inter-relationships among a wide array of variables encompassing psychopathology, premorbid and onset characteristics, cognition, subjective quality-of-life and psychosocial functioning in 323 adult FEP patients in Hong Kong. Graphical Least Absolute Shrinkage and Selection Operator (LASSO) combined with extended Bayesian information criterion (BIC) model selection was used for network construction. Importance of individual nodes in a generated network was quantified by centrality analyses. RESULTS: Our results showed that amotivation played the most central role and had the strongest associations with other variables in the network, as indexed by node strength. Amotivation and diminished expression displayed differential relationships with other nodes, supporting the validity of two-factor negative symptom structure. Psychosocial functioning was most strongly connected with amotivation and was weakly linked to several other variables. Within cognitive domain, digit span demonstrated the highest centrality and was connected with most of the other cognitive variables. Exploratory analysis revealed no significant gender differences in network structure and global strength. CONCLUSION: Our results suggest the pivotal role of amotivation in psychopathology network of FEP and indicate its critical association with psychosocial functioning. Further research is required to verify the clinical significance of diminished motivation on functional outcome in the early course of psychotic illness.

Abnormal cognitive effort allocation and its association with amotivation in first-episode psychosis.

BACKGROUND: Abnormal effort-based decision-making represents a potential mechanism underlying motivational deficits (amotivation) in psychotic disorders. Previous research identified effort allocation impairment in chronic schizophrenia and focused mostly on physical effort modality. No study has investigated cognitive effort allocation in first-episode psychosis (FEP). METHOD: Cognitive effort allocation was examined in 40 FEP patients and 44 demographically-matched healthy controls, using Cognitive Effort-Discounting (COGED) paradigm which quantified participants' willingness to expend cognitive effort in terms of explicit, continuous discounting of monetary rewards based on parametrically-varied cognitive demands (levels N of N-back task). Relationship between reward-discounting and amotivation was investigated. Group differences in reward-magnitude and effort-cost sensitivity, and differential associations of these sensitivity indices with amotivation were explored. RESULTS: Patients displayed significantly greater reward-discounting than controls. In particular, such discounting was most pronounced in patients with high levels of amotivation even when N-back performance and reward base amount were taken into consideration. Moreover, patients exhibited reduced reward-benefit sensitivity and effort-cost sensitivity relative to controls, and that decreased sensitivity to reward-benefit but not effort-cost was correlated with diminished motivation. Reward-discounting and sensitivity indices were generally unrelated to other symptom dimensions, antipsychotic dose and cognitive deficits. CONCLUSION: This study provides the first evidence of cognitive effort-based decision-making impairment in FEP, and indicates that decreased effort expenditure is associated with amotivation. Our findings further suggest that abnormal effort allocation and amotivation might primarily be related to blunted reward valuation. Prospective research is required to clarify the utility of effort-based measures in predicting amotivation and functional outcome in FEP.

Effect of regular precooling on adaptation to training in the heat.

PURPOSE: This study investigated whether regular precooling would help to maintain day-to-day training intensity and improve 20-km cycling time trial (TT) performed in the heat. Twenty males cycled for 10 day × 60 min at perceived exertion equivalent to 15 in the heat (35 °C, 50% relative humidity), preceded by no cooling (CON, n = 10) or 30-min water immersion at 22 °C (PRECOOL, n = 10). METHODS: 19 participants (n = 9 and 10 for CON and PRECOOL, respectively) completed heat stress tests (25-min at 60% [Formula: see text] and 20-km TT) before and after heat acclimation. RESULTS: Changes in mean power output (∆MPO, P = 0.024) and heart rate (∆HR, P = 0.029) during heat acclimation were lower for CON (∆MPO - 2.6 ± 8.1%, ∆HR - 7 ± 7 bpm), compared with PRECOOL (∆MPO + 2.9 ± 6.6%, ∆HR - 1 ± 8 bpm). HR during constant-paced cycling was decreased from the pre-acclimation test in both groups (P < 0.001). Only PRECOOL demonstrated lower rectal temperature (Tre) during constant-paced cycling (P = 0.002) and lower Tre threshold for sweating (P = 0.042). However, skin perfusion and total sweat output did not change in either CON or PRECOOL (all P > 0.05). MPO (P = 0.016) and finish time (P = 0.013) for the 20-km TT were improved in PRECOOL but did not change in CON (P = 0.052 for MPO, P = 0.140 for finish time). CONCLUSION: Precooling maintains day-to-day training intensity and does not appear to attenuate adaptation to training in the heat.

Lung nodules are reliably detectable on ultra-low-dose CT utilising model-based iterative reconstruction with radiation equivalent to plain radiography.

AIM: To determine if ultra-low-dose (ULD) computed tomography (CT) utilising model-based iterative reconstruction (MBIR) with radiation equivalent to plain radiography allows the detection of lung nodules. MATERIALS AND METHODS: Ninety-nine individuals undergoing surveillance of solid pulmonary nodules undertook a low-dose (LD) and ULD CT during the same sitting. Image pairs were read blinded, in random order, and independently by two experienced thoracic radiologists. With LD-CT as the reference standard, the number, size, and location of nodules was compared, and inter-rater agreement was established. RESULTS: There was very good inter-rater agreement with regards nodules ≥4mm for both the LD- (k=0.931) and ULD-CT (k=0.869). One hundred and ninety-nine nodules were reported on the LD-CT by both radiologists and 196 reported on the ULD-CT, with no nodules reported only on the ULD-CT. This gives a sensitivity of 98.5% and specificity of 100% for ULD-CT with MBIR. The effective dose of radiation was significantly different between the two scans (p<0.0001), 1.67 mSv for the LD-CT and 0.13 mSv for the ULD-CT. CONCLUSION: ULD-CT utilising MBIR and delivering radiation equivalent to plain radiography, allows detection of lung nodules with high sensitivity. The attendant 10-fold reduction in radiation may allow for dramatic reductions in cumulative radiation exposure.

The effect of media reporting of a homicide committed by a patient with schizophrenia on the public stigma and knowledge of psychosis among the general population of Hong Kong.

PURPOSE: This study aimed to investigate the effects of media reporting of a homicide committed by a patient with schizophrenia on the knowledge about and stigma regarding psychosis among the general Hong Kong population. The effects of using the term 'schizophrenia (jing-shen-fen-lei)' in the news on the perceptions of the new Chinese term 'psychosis (si-jue-shi-tiao)' were explored. METHODS: Random telephone surveys of the general Hong Kong population were conducted in April 2009 (1 month before the incident) and June 2009 (1 week after the incident). Stigma was measured with the Link's Perceived Discrimination-Devaluation Scale (LPDDS). Knowledge about the symptoms, treatment and belief of dangerousness of psychosis were assessed. The emotional reaction of the public to the news was explored, and its effects on knowledge and stigma were studied. RESULTS: Overall, 1016 and 506 participants completed the two surveys. More participants in the post-incident survey agreed that people with psychosis are dangerous to the public (χ2 = 4.934, p = 0.026). However, no significant differences were observed in the LPDDS scores. Participants who reported a high level of distress related to the news were more likely to perceive people with psychosis as dangerous to the public (χ2 = 6.738, p = 0.009). Women and older people reported greater distress. CONCLUSIONS: These findings suggest that media reporting of violent incidents involving people with schizophrenia increases the public belief in the dangerousness of people with psychosis but not the overall stigma. Further studies of the differential effects of violence reporting on public perceptions about people with psychosis and schizophrenia are warranted.

Review of Polygonatum sibiricum: A new natural cosmetic ingredient.

With the developments of science and technology, social development and people's pursuit of quality life, natural and safe skin care products occupied half of the cosmetics industry. In recent years, as synthetic drugs were found that which had toxic and some side effects, people have a tendency to return to nature. Thus, traditional Chinese medicinal plants were applied to natural cosmetics with good efficacy, little side effects and no allergy which had more advantages than synthetic products. The cosmetic products with pure natural ingredients were more and more favored by consumers. Therefore, the article mainly pays attention to the relationship between the active ingredients of Polygonatum sibiricum (PS) and their cosmetic effects, mainly included anti-aging activity, anti-bacteria effect, skin whitening and moisturizing effects. The article will provide more possibilities for research of natural ingredients cosmetics.

Delayed-type hypersensitivity reactions induced by proton pump inhibitors: A clinical and in vitro T-cell reactivity study.

BACKGROUND: Proton pump inhibitors (PPIs) have been known to induce type I hypersensitivity reactions. However, severe delayed-type hypersensitivity reactions (DHR) induced by PPI, such as Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), or drug rash with eosinophilia and systemic symptoms (DRESS), are rarely reported. We conducted a study of a large series of PPI-related DHR, followed up their tolerability to alternative anti-ulcer agents, and investigated the T-cell reactivity to PPI in PPI-related DHR patients. METHODS: We retrospectively analyzed patients with PPI-related DHR from multiple medical centers in Taiwan during the study period January 2003 to April 2016. We analyzed the causative PPI, clinical manifestations, organ involvement, treatment, and complications. We also followed up the potential risk of cross-hypersensitivity or tolerability to other PPI after their hypersensitivity episodes. Drug lymphocyte activation test (LAT) was conducted by measuring granulysin and interferon-γ to confirm the causalities. RESULTS: There were 69 cases of PPI-related DHR, including SJS/TEN (n=27) and DRESS (n=10). The LAT by measuring granulysin showed a sensitivity of 59.3% and specificity of 96.4%. Esomeprazole was the most commonly involved in PPI-related DHR (51%). Thirteen patients allergic to one kind of PPI could tolerate other structurally different PPI without cross-hypersensitivity reactions, whereas three patients developed cross-hypersensitivity reactions to alternative structurally similar PPI. The cross-reactivity to structurally similar PPI was also observed in LAT assay. CONCLUSIONS: PPIs have the potential to induce life-threatening DHR. In patients when PPI is necessary for treatment, switching to structurally different alternatives should be considered.

Relationship of amotivation to neurocognition, self-efficacy and functioning in first-episode psychosis: a structural equation modeling approach.

BACKGROUND: Better understanding of the complex interplay among key determinants of functional outcome is crucial to promoting recovery in psychotic disorders. However, this is understudied in the early course of illness. We aimed to examine the relationships among negative symptoms, neurocognition, general self-efficacy and global functioning in first-episode psychosis (FEP) patients using structural equation modeling (SEM). METHOD: Three hundred and twenty-one Chinese patients aged 26-55 years presenting with FEP to an early intervention program in Hong Kong were recruited. Assessments encompassing symptom profiles, functioning, perceived general self-efficacy and a battery of neurocognitive tests were conducted. Negative symptom measurement was subdivided into amotivation and diminished expression (DE) domain scores based on the ratings in the Scale for the Assessment of Negative Symptoms. RESULTS: An initial SEM model showed no significant association between functioning and DE which was removed from further analysis. A final trimmed model yielded very good model fit (χ2 = 15.48, p = 0.63; comparative fit index = 1.00; root mean square error of approximation <0.001) and demonstrated that amotivation, neurocognition and general self-efficacy had a direct effect on global functioning. Amotivation was also found to mediate a significant indirect effect of neurocognition and general self-efficacy on functioning. Neurocognition was not significantly related to general self-efficacy. CONCLUSION: Our results indicate a critical intermediary role of amotivation in linking neurocognitive impairment to functioning in FEP. General self-efficacy may represent a promising treatment target for improvement of motivational deficits and functional outcome in the early illness stage.

Gender effect on public stigma changes towards psychosis in the Hong Kong Chinese population: a comparison between population surveys of 2009 and 2014.

PURPOSE: Public stigma is an important barrier to the recovery of patients with psychosis. The current study aimed to investigate the change in stigma towards psychosis and knowledge about psychosis between 2009 and 2014 among the Chinese population in Hong Kong, with a specific focus on gender role. METHODS: Random telephone survey of general population in Hong Kong was conducted in 2009 and 2014. Stigma was measured with the revised Link's Perceived Discrimination-Devaluation Scale (LPDDS). Logistic regression was used to explore the effect of time on the change of knowledge of psychosis, and linear regression was used to explore the effect of time on the change of stigma. Change of knowledge and stigma based on gender was specifically explored. RESULTS: In total, 1016 and 1018 subjects completed the survey in 2009 and 2014, respectively. Significantly, more people agreed with medication treatment for psychosis and fewer people had misunderstanding about psychosis. However, there was no significant change in stigma levels. Males were found to have a significant deterioration of stigma (B = 0.099, SE = 0.033, ß = 0.100, p = 0.003) but not females. Significantly, more males endorsed medication treatment for psychosis (χ 2 = 5.850, df = 1, p = 0.016) but no change for females (χ 2 = 1.401, df = 1, p = 0.238). CONCLUSIONS: Results of this study suggested that there was an improvement in the biological understanding of psychosis but no change of public stigma within the Hong Kong Chinese population. The specific role of gender in relation to stigma and level of knowledge about psychosis indicates that this should be a consideration in designing future anti-stigma campaigns.