Adolescent diet, physical activity and nutritional status are generally known to be sub-optimal. This is an introduction to a special issue of papers devoted to exploring factors affecting diet and physical activity in adolescents, including food insecure and vulnerable groups.

Eight settings including urban, peri-urban and rural across sites from five different low- and middle-income countries.

Focus groups with adolescents and caregivers carried out by trained researchers.

Our results show that adolescents, even in poor settings, know about healthy diet and lifestyles. They want to have energy, feel happy, look good and live longer, but their desire for autonomy, a need to ‘belong’ in their peer group, plus vulnerability to marketing exploiting their aspirations, leads them to make unhealthy choices. They describe significant gender, culture and context-specific barriers. For example, urban adolescents had easy access to energy dense, unhealthy foods bought outside the home, whereas junk foods were only beginning to permeate rural sites. Among adolescents in Indian sites, pressure to excel in exams meant that academic studies were squeezing out physical activity time.

Interventions to improve adolescents’ diets and physical activity levels must therefore address structural and environmental issues and influences in their homes and schools, since it is clear that their food and activity choices are the product of an interacting complex of factors. In the next phase of work, the Transforming Adolescent Lives through Nutrition consortium will employ groups of adolescents, caregivers and local stakeholders in each site to develop interventions to improve adolescent nutritional status.

To explore perceptions of how context shapes adolescent diet and physical activity in eight low- and middle-income (LMIC) sites at different stages of societal and economic transition.

Novel qualitative secondary analysis of eight data sets generated as part of the international Transforming Adolescent Lives through Nutrition (TALENT) collaboration.

Diverse sites in India and Sub-Saharan Africa.

Fifty-two focus group discussions with 491 participants (303 adolescents aged 10–17 years; 188 caregivers).

Analysis of pooled qualitative data identified three themes: (1) transitions in generational nutrition education and knowledge; (2) transition in caregiver–adolescent power balance and (3) the implications of societal and economic transition for diet and physical activity. Adolescents in urban and peri-urban areas could readily access ‘junk’ food. Diets in rural settings were determined by tradition, seasonality and affordability. Physical activity was inhibited by site-specific factors including lack of space and crime in urban settings, and the prioritisation of academic performance. Gender influenced physical activity across all sites, with girls afforded fewer opportunities.

Interventions to improve adolescent diet and physical activity in LMIC need to be complex, context-specific and responsive to transitions at the individual, economic and societal levels. Moreover, solutions need to acknowledge gender inequalities in different contexts, as well as structural and cultural influences on diet and physical activity in resource-limited settings. Programmes need to be effective in engaging and reconciling adolescents’ and caregivers’ perspectives. Consequently, there is a need for action at both the community-household level and also through policy.

Although neuroimaging studies suggest brain regional abnormalities in depressive disorders, it remains unclear whether abnormalities are present at illness onset or reflect disease progression.

We hypothesized that cerebral variations were present in adolescents with subthreshold depression known to be at high risk for later full-blown depression.

We examined brain structural and diffusion-weighted magnetic resonance images of adolescents with subthreshold depression.

The participants were extracted from the European IMAGEN study cohort of healthy adolescents recruited at age 14. Subthreshold depression was defined as a distinct period of abnormally depressed or irritable mood, or loss of interest, plus two or more depressive symptoms but without diagnosis of Major Depressive Episode. Comparisons were performed between adolescents meeting these criteria and control adolescents within the T1-weighted imaging modality (118 and 475 adolescents respectively) using voxel-based morphometry and the diffusion tensor imaging modality (89 ad 422 adolescents respectively) using tract-based spatial statistics. Whole brain analyses were performed with a statistical threshold set to p< 0.05 corrected for multiple comparisons.

Compared with controls, adolescents with subthreshold depression had smaller gray matter volume in caudate nuclei, medial frontal and cingulate cortices; smaller white matter volume in anterior limb of internal capsules, left forceps minor and right cingulum; and lower fractional anisotropy and higher radial diffusivity in the genu of corpus callosum.

The findings suggest that adolescents with subthreshold depression have volumetric and microstructural gray and white matter changes in the emotion regulation frontal-striatal-limbic network.

To: (i) understand facilitators and barriers to healthy eating practices and physical activity in younger and older urban adolescent South African boys and girls; and (ii) understand how the views of caregivers interact with, and influence, adolescent behaviours.

Semi-structured focus group discussions (FGD) were conducted in July 2018. Data were analysed using thematic analysis.

Soweto, Johannesburg, South Africa.

Seventy-five participants were stratified into eight FGD as follows: two for young boys and girls (10–12 years); two for older boys and girls (15–17 years); two for caregivers of young adolescents (boys and girls); and two for caregivers of older adolescents (boys and girls).

Unlike their caregivers, adolescents were not motivated to eat healthily and failed to appreciate the need to develop consistent patterns of both healthy eating and physical activity for their long-term health. Although adolescents gained independence with age, they commonly attributed unhealthy food choices to a lack of autonomy and, thereby, to the influence of their caregivers. Adolescents and caregivers perceived their engagement in physical activity according to distinct siloes of recreational and routine activity, respectively. Both similarities and differences in the drivers of healthy eating and physical activity exist in adolescents and caregivers, and should be targeted in future interventions.

Our study identified a complex paradigm of eating practices and physical activity in South African adolescents and their caregivers. We also highlighted the need for a new narrative in addressing the multifaceted and interrelated determinants of adolescent health within urban poor settings.

A few studies have evaluated the impact of clinical trial results on practice in paediatric cardiology. The Infant Single Ventricle (ISV) Trial results published in 2010 did not support routine use of the angiotensin-converting enzyme inhibitor enalapril in infants with single-ventricle physiology. We sought to assess the influence of these findings on clinical practice.

A web-based survey was distributed via e-mail to over 2000 paediatric cardiologists, intensivists, cardiothoracic surgeons, and cardiac advance practice nurses during three distribution periods. The results were analysed using McNemar’s test for paired data and Fisher’s exact test.

The response rate was 31.5% (69% cardiologists and 65% with >10 years of experience). Among respondents familiar with trial results, 74% reported current practice consistent with trial findings versus 48% before trial publication (p<0.001); 19% used angiotensin-converting enzyme inhibitor in this population “almost always” versus 36% in the past (p<0.001), and 72% reported a change in management or improved confidence in treatment decisions involving this therapy based on the trial results. Respondents familiar with trial results (78%) were marginally more likely to practise consistent with the trial results than those unfamiliar (74 versus 67%, p=0.16). Among all respondents, 28% reported less frequent use of angiotensin-converting enzyme inhibitor over the last 3 years.

Within 5 years of publication, the majority of respondents was familiar with the Infant Single Ventricle Trial results and reported less frequent use of angiotensin-converting enzyme inhibitor in single-ventricle infants; however, 28% reported not adjusting their clinical decisions based on the trial’s findings.

This study evaluated dosimetric parameters for cervical high-dose-rate (HDR) brachytherapy treatment using varying dose prescription methods.

This study includes 125 tandem-based cervical HDR brachytherapy treatment plans of 25 patients who received HDR brachytherapy. Delineation of high-risk clinical target volumes (HR-CTVs) and organ at risk were done on original computed tomographic images. The dose prescription point was defined as per International Commission in Radiation Units and Measurements Report Number 38 (ICRU-38), also redefined using American Brachytherapy Society (ABS) 2011 criteria. The coverage index (V100) for each HR-CTV was calculated using dose volume histogram parameters. A plot between HR-CTV and V100 was plotted using the best-fit linear regression line (least-square fit analysis).

Mean prescribed dose to ICRU-38 Point A was 590·47±28·65 cGy, and to ABS Point A was 593·35±30·42 cGy. There was no statistically significant difference between planned ICRU-38 and calculated ABS Point A doses (p=0·23). The plot between HR-CTV and V100 is well defined by the best-fit linear regression line with a correlation coefficient of 0·9519.

For cervical HDR brachytherapy, dose prescription to an arbitrarily defined point (e.g., Point A) does not provide consistent coverage of HR-CTV. The difference in coverage between two dose prescription approaches increases with increasing CTV. Our ongoing work evaluates the dosimetric consequences of volumetric dose prescription approaches for these patients.

There is now a well-established link between childhood adversity (CA) and schizophrenia. Similar structural abnormalities to those found in schizophrenia including alterations in grey-matter volume have also been shown in those who experience CA.

We examined whether global estimates of cortical thickness or surface area were altered in those familial high-risk subjects who had been referred to a social worker or the Children's Panel compared to those who had not.

We found that the cortical surface area of those who were referred to the Children's Panel was significantly smaller than those who had not been referred, but cortical thickness was not significantly altered. There was also an effect of social work referral on cortical surface area but not on thickness.

Cortical surface area increases post-natally more than cortical thickness. Our findings suggest that CA can influence structural changes in the brain and it is likely to have a greater impact on cortical surface area than on cortical thickness.

Resilience is the capacity of individuals to resist mental disorders despite exposure to stress. Little is known about its neural underpinnings. The putative variation of white-matter microstructure with resilience in adolescence, a critical period for brain maturation and onset of high-prevalence mental disorders, has not been assessed by diffusion tensor imaging (DTI). Lower fractional anisotropy (FA) though, has been reported in the corpus callosum (CC), the brain's largest white-matter structure, in psychiatric and stress-related conditions. We hypothesized that higher FA in the CC would characterize stress-resilient adolescents.

Three groups of adolescents recruited from the community were compared: resilient with low risk of mental disorder despite high exposure to lifetime stress (n = 55), at-risk of mental disorder exposed to the same level of stress (n = 68), and controls (n = 123). Personality was assessed by the NEO-Five Factor Inventory (NEO-FFI). Voxelwise statistics of DTI values in CC were obtained using tract-based spatial statistics. Regional projections were identified by probabilistic tractography.

Higher FA values were detected in the anterior CC of resilient compared to both non-resilient and control adolescents. FA values varied according to resilience capacity. Seed regional changes in anterior CC projected onto anterior cingulate and frontal cortex. Neuroticism and three other NEO-FFI factor scores differentiated non-resilient participants from the other two groups.

High FA was detected in resilient adolescents in an anterior CC region projecting to frontal areas subserving cognitive resources. Psychiatric risk was associated with personality characteristics. Resilience in adolescence may be related to white-matter microstructure.

Impulsivity is a core feature of borderline personality disorder (BPD) and is most frequently measured using self-rating scales. There is a need to find objective, valid and reliable measures of impulsivity. This study aimed to examine performance of participants with BPD compared with healthy controls on delay and probabilistic discounting tasks and the stop-signal task (SST), which are objective measures of choice and motor impulsivity, respectively.

A total of 20 participants with BPD and 21 healthy control participants completed delay and probabilistic discounting tasks and the SST. They also completed the Barratt Impulsiveness Scale (BIS), a self-rating measure of impulsivity.

Participants with BPD showed significantly greater delay discounting than controls, manifest as a greater tendency to accept the immediately available lesser reward rather than waiting longer for a greater reward. Similarly they showed significantly greater discounting of rewards by the probability of payout, which correlated with past childhood trauma. Participants with BPD were found to choose the more certain and/or immediate rewards, irrespective of the value. On the SST the BPD and control groups did not differ significantly, demonstrating no difference in motor impulsivity. There was no significant difference between groups on self-reported impulsivity as measured by the BIS.

Measures of impulsivity show that while motor impulsivity was not significantly different in participants with BPD compared with controls, choice or reward-related impulsivity was significantly affected in those with BPD. This suggests that choice impulsivity but not motor impulsivity is a core feature of BPD.