The molecular genetic architecture of attention deficit hyperactivity disorder

Attention deficit hyperactivity disorder (ADHD) is a common childhood behavioral condition which affects 2-10% of school age children worldwide. Although the underlying molecular mechanism for the disorder is poorly understood, familial, twin and adoption studies suggest a strong genetic component. Here we provide a state-of-the-art review of the molecular genetics of ADHD incorporating evidence from candidate gene and linkage designs, as well as genome-wide association (GWA) studies of common single-nucleotide polymorphisms (SNPs) and rare copy number variations (CNVs). Bioinformatic methods such as functional enrichment analysis and protein-protein network analysis are used to highlight biological processes of likely relevance to the aetiology of ADHD. Candidate gene associations of minor effect size have been replicated across a number of genes including SLC6A3, DRD5, DRD4, SLC6A4, LPHN3, SNAP-25, HTR1B, NOS1 and GIT1. Although case-control SNP-GWAS have had limited success in identifying common genetic variants for ADHD that surpass critical significance thresholds, quantitative trait designs suggest promising associations with Cadherin13 and glucose-fructose oxidoreductase domain 1 genes. Further, CNVs mapped to glutamate receptor genes (GRM1, GRM5, GRM7 and GRM8) have been implicated in the aetiology of the disorder and overlap with bioinformatic predictions based on ADHD GWAS SNP data regarding enriched pathways. Although increases in sample size across multi-center cohorts will likely yield important new results, we advocate that this must occur in parallel with a shift away from categorical case-control approaches that view ADHD as a unitary construct, towards dimensional approaches that incorporate endophenotypes and statistical classification methods.

How standard is standard care? Exploring control group outcomes in behaviour change interventions for young people with type 1 diabetes

OBJECTIVE

Poor descriptions of standard care may compromise interpretation of results in randomised controlled trials (RCTs) of health interventions. We investigated quality of standard care in RCTs of behaviour change interventions for young people with type 1 diabetes and consider implications for evaluating trial outcomes.

DESIGN

We conducted systematic searches for articles published between 1999 and 2012. We extracted standard care descriptions and contacted trial authors to complete a checklist of standard care activities. The relationship between standard care quality and outcomes was examined via subgroup meta-analyses and meta-regression.

MAIN OUTCOME MEASURES

Standard care descriptions, standard care quality, and relationships between standard care quality with medical and psychological outcomes.

RESULTS

We identified 20 RCTs described across 26 articles. Published descriptions of standard care were limited to service-level features. Author responses indicated standard care provision extended beyond published accounts. Subgroup analyses suggested control groups receiving higher standard care quality showed larger improvements in both medical and psychological outcomes, although standard care quality did not predict outcomes significantly.

CONCLUSION

The quality of care delivered to control group participants can influence outcomes of RCTs. Inadequate reporting exacerbates this issue by masking variations between trials. We argue for increased clarity in reporting standard care in future trials.

Ten-year changes in positive and negative marker food, fruit, vegetables, and salad intake in 9-10 year olds: SportsLinx 2000-2001 to 2010-2011

BACKGROUND

To investigate changes in intakes of 'negative' and 'positive' foods, fruit, vegetables, and salad in serial cohorts of 9-10-year-old children from 2000-2001 to 2010-2011.

METHODS

For this serial, cross-sectional study, children in school year 5 (9-10 years of age) completed the SportsLinx Lifestyles Survey [n = 30,239 (15,336 boys and 14,903 girls)]. Changes in positive and negative food scores, and the proportion of boys and girls reportedly consuming fruit, vegetables and salad on the previous day to surveying, were investigated annually from 2000 to 2011.

RESULTS

The consumption of negative foods declined and positive foods increased significantly compared to baseline. Positive changes in fruit, vegetables and salad consumption were observed over time, with the most recent cohort more likely to consume fruit, vegetables and salad compared to the 2000-2001 baseline. Girls displayed more favourable positive and negative food scores and were more likely to consume fruit, salad and vegetables across several study years compared to boys.

CONCLUSIONS

The consumption of negative and positive foods, fruit, vegetables, and salad has improved over the last 10 years. In addition, girls appear to have better positive and negative food scores, and were more likely to consume fruit, vegetables and salad, across a number of study years or cohorts compared to boys. These encouraging findings suggest that children's food intake has improved since 2000. Furthermore, the data indicate that boys and girls may require separate or different healthy eating messages to further improve food intake.

Low-dose phase contrast mammography with conventional x-ray sources

PURPOSE

To provide an x-ray phase contrast imaging (XPCI) method working with conventional sources that could be readily translated into clinical practice. XPCI shows potential in synchrotron studies but attempts at translating it for use with conventional sources are subject to limitations in terms of field of view, stability, exposure time, and possibly most importantly, delivered dose.

METHODS

Following the adaptation of our "edge-illumination" XPCI technique for use with conventional x-ray sources through the use of x-ray masks, the authors have further modified the design of such masks to allow further reducing the dose delivered to the sample without affecting the phase sensitivity of the method.

RESULTS

The authors have built a prototype based on the new mask design and used it to image ex vivo breast tissue samples containing malignant lesions. The authors compared images acquired with this prototype to those obtained with a conventional system. The authors demonstrate and quantify image improvements, especially in terms of microcalcification detection. On calcifications detected also by the conventional system, the authors measure contrast increases from five to nine fold; calcifications and other features were also detected which are completely invisible in the conventional image. Dose measurements confirmed that the above enhancements were achieved while delivering doses compatible with clinical practice.

CONCLUSIONS

The authors obtained phase-related image enhancements in mammography by means of a system built with components available off-the-shelf that operates under exposure time and dose conditions compatible with clinical practice. This opens the way to a straightforward translation of phase enhanced imaging methods into clinical practice.

Medical and psychological outcomes for young adults with Type 1 diabetes: no improvement despite recent advances in diabetes care

AIM

To assess medical and psychological outcomes among young people with Type 1 diabetes and to compare medical outcomes with a previous audit.

METHODS

An observational study in two diabetes clinics for young adults (aged 16-21 years) in Sheffield, UK. Young people (n = 96: 81.4% response rate) with Type 1 diabetes (diagnosed > 6 months) completed measures of depressive symptoms, anxiety and disordered eating and consented for their medical records to be consulted.

RESULTS

Mean HbA1c (86 ± 23 mmol/mol; 10.0 ± 2.1%); was comparable with that reported previously and considerably higher than recommended (< 58 mmol/mol or 7.5%). Screening rates were improved and non-attendance was lower than previously reported, but levels of non-proliferative retinopathy have increased. Microvascular complications are present in 46.9% of those diagnosed more than 7 years. Elevated levels of disordered eating were reported by 35.1%. Those scoring above cut-off levels for clinical anxiety (26.6%) and depression (10.9%) are comparable with other work with young people with Type 1 diabetes.

CONCLUSIONS

Despite technological advances and improvements to delivery of care, HbA1c remain above recommended levels in a significant proportion of young people, many of whom already have microvascular complications. We need to learn from European centres who achieve better results, improve transition from paediatric care, integrate mental health support with diabetes care provision and take into account young people's views about clinic.