Bumpy Power Spectra and dT/T

With the recent publication of the measurements of the radiation angular power spectrum from the BOOMERanG Antarctic flight (de Bernardis et al. 2000), it has become apparent that the currently favoured spatially-flat cold dark matter model (matter density parameter $\Omega_{\rm m}=0.3$, flatness being restored by a cosmological constant $\Omega_{\Lambda}=0.7$, Hubble parameter $h=0.65$, baryon density parameter $\Omega_{\rm b}h^2=0.02$) no longer provides a good fit to the data. We describe a phenomenological approach to resurrecting this paradigm. We consider a primordial power spectrum which incorporates a bump, arbitrarily placed at $k_{\rm b}$, and characterized by a Gaussian in log $k$ of standard deviation $\sigma_{\rm b}$ and amplitude ${\rm A}_{\rm b}$, that is superimposed onto a scale-invariant power spectrum. We generate a range of theoretical models that include a bump at scales consistent with cosmic microwave background and large-scale structure observations, and perform a simple $\chi^2$ test to compare our models with the $COBE$ DMR data and the recently published BOOMERanG and MAXIMA data. Unlike models that include a high baryon content, our models predict a low third acoustic peak. We find that low $\ell$ observations (20 $< \ell <$ 200) are a critical discriminant of the bumps because the transfer function has a sharp cutoff on the high $\ell$ side of the first acoustic peak...Comment: 5 pages, 5 figures, updated reference

Internet-based CBT for depression with and without telephone tracking in a national helpline: randomised controlled trial

BACKGROUND Telephone helplines are frequently and repeatedly used by individuals with chronic mental health problems and web interventions may be an effective tool for reducing depression in this population. AIM To evaluate the effectiveness of a 6 week, web-based cognitive behaviour therapy (CBT) intervention with and without proactive weekly telephone tracking in the reduction of depression in callers to a helpline service. METHOD 155 callers to a national helpline service with moderate to high psychological distress were recruited and randomised to receive either Internet CBT plus weekly telephone follow-up; Internet CBT only; weekly telephone follow-up only; or treatment as usual. RESULTS Depression was lower in participants in the web intervention conditions both with and without telephone tracking compared to the treatment as usual condition both at post intervention and at 6 month follow-up. Telephone tracking provided by a lay telephone counsellor did not confer any additional advantage in terms of symptom reduction or adherence. CONCLUSIONS A web-based CBT program is effective both with and without telephone tracking for reducing depression in callers to a national helpline. TRIAL REGISTRATION Controlled-Trials.comISRCTN93903959.Funding for the trial was provided by an Australian Research Council Linkage Project Grant (LP0667970) (http://www.arc.gov.au/). LF is supported by an Australian Postgraduate Award Industry scholarship. KG is supported by a National Health and Medical Research Council Fellowship (No. 525413) and HC is supported by a National Health and Medical Research Council Fellowship (No. 525411)

Age differences in mental health literacy

BACKGROUND: The community's knowledge and beliefs about mental health problems, their risk factors, treatments and sources of help may vary as a function of age. METHODS: Data were taken from an epidemiological survey conducted during 2003–2004 with a national clustered sample of Australian adults aged 18 years and over. Following the presentation of a vignette describing depression (n = 1001) or schizophrenia (n = 997), respondents were asked a series of questions relating to their knowledge and recognition of the disorder, beliefs about the helpfulness of treating professionals and medical, psychological and lifestyle treatments, and likely causes. RESULTS: Participant age was coded into five categories and cross-tabulated with mental health literacy variables. Comparisons between age groups revealed that although older adults (70+ years) were poorer than younger age groups at correctly recognising depression and schizophrenia, young adults (18–24 years) were more likely to misidentify schizophrenia as depression. Differences were also observed between younger and older age groups in terms of beliefs about the helpfulness of certain treating professionals and medical and lifestyle treatments for depression and schizophrenia, and older respondents were more likely to believe that schizophrenia could be caused by character weakness. CONCLUSION: Differences in mental health literacy across the adult lifespan suggest that more specific, age appropriate messages about mental health are required for younger and older age groups. The tendency for young adults to 'over-identify' depression signals the need for awareness campaigns to focus on differentiation between mental disorders

Is the Pre-WMAP CMB Data Self-consistent?

Although individual observational groups vigorously test their data sets for systematic errors, the pre-WMAP CMB observational data set has not yet been collectively tested. Under the assumption that the concordance model is the correct model, we have explored residuals of the observational data with respect to this model to see if any patterns emerge that can be identified with systematic errors. We found no significant trends associated with frequency, frequency channels, calibration source, pointing uncertainty, instrument type, platform and altitude. We did find some evidence at the ~ 1 to ~ 2 sigma level for trends associated with angular scale (l range) and absolute galactic latitude. The slope of the trend in galactic latitude is consistent with low level galactic contamination. The residuals with respect to l may indicate that the concordance model used here needs slight modification. See Griffiths & Lineweaver (2003) for more detail.Comment: 8 pages, 4 figures, to be published in the proceedings of "The Cosmic Microwave Background and its Polarization", New Astronomy Reviews, (eds. S. Hanany and K.A. Olive

The effect of a web based depression intervention on suicide ideation: secondary outcome from a randomised controlled trial in a helpline

Objectives: The effect of web-based interventions for depression on suicide ideation in callers to helplines is not known. The aim of this study was to determine if web-based Cognitive Behaviour Therapy (CBT) with and without telephone support is effective in reducing suicide ideation in callers to a helpline compared with treatment as usual (TAU). A secondary aim was to examine the factors that predict change in suicide ideation. Putative predictors included level of baseline depression, suicide behaviour, baseline anxiety and type of intervention. Design: Randomised controlled trial. Setting: Lifeline, Australia’s 24 h telephone counselling service participants: 155 callers to a national helpline service with moderate-to-high psychological distress. Interventions: Participants were recruited and randomised to receive either 6 weeks of internet CBT plus weekly telephone follow-up; internet CBT only; weekly telephone follow-up only or a wait-list TAU control group. Primary and secondary outcome measures: Suicidal ideation was measured using four items from the 28-item General Health Questionnaire. Predictors of change in ideation were tested using logistic regression analysis. Results: Regardless of the intervention condition, participants showed significant reductions in suicidal ideation over 12 months (p<0.001). Higher baseline suicidal behaviour decreased the odds of remission of suicidal ideation at postintervention (OR 0.409, p<0.001). However, change in depression over the course of the interventions was associated with improvement in suicide ideation (OR 1.165, p<0.001). Conclusions: Suicide ideation declines with and without proactive intervention. Improvements in depression are associated with the resolution of suicide ideation. Specific interventions focusing on suicide ideation should be further investigated.Australian Research Council Linkage Grant (LP0667970), 2006, 3 years, $279 325 (Christensen, Griffiths, Mackinnon, Smith), Internet technologies, health informatics, and statistical models, and new delivery platforms in call centres (CIA). HC and PB were supported by NHMRC 525411 and NHMRC Early Career Fellowship 1035262. KMG is supported by NHMRC Fellowship No. 525413

Demographic and psychosocial predictors of major depression and generalised anxiety disorder in Australian university students

Abstract Background Few studies have examined modifiable psychosocial risk factors for mental disorders among university students, and of these, none have employed measures that correspond to clinical diagnostic criteria. The aim of this study was to examine psychosocial and demographic risk factors for major depression and generalised anxiety disorder (GAD) in a sample of Australian university students. Methods An anonymous web-based survey was distributed to undergraduate and postgraduate students at a mid-sized Australian university. A range of psychosocial and demographic risk factors were measured, and logistic regression models were used to examine significant predictors of major depression and GAD. Results A total of 611 students completed the survey. The prevalence of major depression and GAD in the sample was 7.9 and 17.5 %, respectively. In terms of demographic factors, the risk of depression was higher for students in their first year of undergraduate study, and the risk of GAD was higher for female students, those who moved to attend university, and students experiencing financial stress. In terms of psychosocial factors, students with experience of body image issues and lack of confidence were at significantly greater risk of major depression, and feeling too much pressure to succeed, lack of confidence, and difficulty coping with study was significantly associated with risk of GAD. Conclusions University students experience a range of unique psychosocial stressors that increase their risk of major depression and GAD, in addition to sociodemographic risk factors. It is important to examine psychosocial factors, as these are potentially modifiable and could be the focus of university-specific mental health interventions.This project was resourced by the Young and Well CRC (youngandwellcrc.org.au). The Young and Well CRC is established under the Australian Government’s Cooperative Research Centres Program. KMG is supported by a National Health and Medical Research Council Fellowship (No.1059620)

Large extra dimensions, the galaxy power spectrum and the end of inflation

We consider the production of gravitational KK modes via cosmological photon-photon and electron-positron annihilation in models with large factorisable extra dimensions. We place constraints on this production using recent results from a joint analysis of the power spectra of the 2dF Galaxy Redshift Survey (2dFGS) and the cosmic microwave background (CMB) anisotropies. We obtain a more accurate upper limit for the temperature corresponding to matter-radiation equality and show that, even for the case of 6 extra dimensions and a fundamental scale of 1 TeV, a period of inflation is required that ends at a temperature much lower than that of the QCD phase transition.Comment: 12 pages, 2 figures, hadronic branching+typos corrected,accepted in JHE

CMB Constraints on a Baryonic Dark Matter-Dominated Universe

In recent years, upper limits on the cosmic microwave background (CMB) anisotropies combined with predictions made by theories of galaxy formation, have been extremely powerful in ruling out purely baryonic dark matter (BDM) universes. However, it has recently been argued that the absence of a prominent second peak in the anisotropy spectrum measured by the BOOMERanG-98 and MAXIMA-1 experiments seems to favour a $\Lambda$BDM model when combined with standard Big Bang Nucleosynthesis (BBN) constraints. In this {\it Letter}, we further investigate this result showing that, using the CMB data {\it alone}, a purely baryonic adiabatic model of structure formation seems unlikely if the universe is flat ($\Omega=1$). Combining the CMB data with supernova type Ia (SNIa) data renders purely baryonic models inconsistent with flatness at high significance and more than $3 \sigma$ away from both the BBN constraints and the HST key project result $h=0.72 \pm 0.08$. These results indicate that only a radical revision of cosmology with {\it ad hoc} properties could bring baryonic models such as those advocated by MOND enthusiasts back into agreement with current observations.Comment: 5 pages LaTeX file, with 3 figures incorporated (uses emulateapj.sty and epsf). ApJ Letters accepted versio

The effectiveness of an online support group for members of the community with depression: a randomised controlled trial

Background: Internet support groups (ISGs) are popular, particularly among people with depression, but there is little high quality evidence concerning their effectiveness. Aim: The study aimed to evaluate the efficacy of an ISG for reducing depressive symptoms among community members when used alone and in combination with an automated Internet-based psychotherapy training program. Method: Volunteers with elevated psychological distress were identified using a community-based screening postal survey. Participants were randomised to one of four 12-week conditions: depression Internet Support Group (ISG), automated depression Internet Training Program (ITP), combination of the two (ITP+ISG), or a control website with delayed access to ecouch at 6 months. Assessments were conducted at baseline, post-intervention, 6 and 12 months. Results: There was no change in depressive symptoms relative to control after 3 months of exposure to the ISG. However, both the ISG alone and the combined ISG+ITP group showed significantly greater reduction in depressive symptoms at 6 and 12 months follow-up than the control group. The ITP program was effective relative to control at post-intervention but not at 6 months. Conclusions: ISGs for depression are promising and warrant further empirical investigation.The trial was funded by a National Health and Medical Research Council Project Grant 471435. KG is supported by NHMRC Fellowship No. 525413 and HC is supported by Fellowship No. 525411. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Exploring content and psychometric validity of newly developed assessment tools for itch and skin pain in atopic dermatitis.

BackgroundAtopic dermatitis (AD) is a common skin disorder characterized by chronic inflammation, altered skin barrier function, and inflammatory cell skin infiltration that decreases health-related quality of life (HRQoL). The study objective was to understand the patient perspective of AD burden and determine suitable patient-reported outcome (PRO) measures.MethodsThis mixed methods study involved the collection of qualitative and quantitative information from adults (≥ 18 years old) and adolescents (12 - 17 years old) with clinician-confirmed AD regarding their experiences of AD symptoms and its impact on HRQoL. The first part of the study included three stages: in-person concept elicitation (CE) interviews, a 2-week daily electronic diary (eDiary) study, and in-person cognitive debriefing (CD) interviews. An Itch numeric rating scale (NRS) (v1.0) and a Skin Pain NRS (v1.0) evaluation during CD interviews required participants to think about their 'worst' itch and 'worst' skin pain in the past 24 h. Other PRO measures allowed for psychometric testing. The second part of the study involved telephone-depth interviews (TDIs) and qualitative feedback from participants who had not participated in the CD interviews. Qualitative data were thematically analyzed. Psychometric evaluation of NRS measures was performed using eDiary data.ResultsIn the CE interviews, itch and/or itching and skin pain were the most prevalent symptoms consistently discussed by participants. Both NRS measures demonstrated strong psychometric reliability and were applicable across ages with suitable concurrent validity. During the CD interviews, some participants focused their answers on their 'average' itch/itching in the past 24 h, rather than their 'worst' itch. Some participants answered the Skin Pain NRS thinking about general pain or other types of pain, rather than skin pain specifically. Consequently, modifications to both measures addressed these issues and re-tested as paper-and-pen versions in subsequent TDIs. Itch NRS (v2.0) modifications helped participants focus on their worst itching. Most participants preferred Skin Pain NRS v2.0b, which included skin pain descriptors.ConclusionsItching and skin pain are the most important and relevant AD symptoms. The Itch NRS (v2.0) and Skin Pain NRS (v2.0b) appear to be appropriate endpoints for the assessment of itching and skin pain severity for clinical trials with adults and adolescents with AD