A local Vapnik–Chervonenkis complexity

We define in this work a new localized version of a Vapnik–Chervonenkis (VC) complexity, namely the Local VC-Entropy, and, building on this new complexity, we derive a new generalization bound for binary classifiers. The Local VC-Entropy-based bound improves on the original Vapnik’s results because it is able to discard those functions that, most likely, will not be selected during the learning phase. The result is achieved by applying the localization principle to the original global complexity measure, in the same spirit of the Local Rademacher Complexity. By exploiting and improving a recently developed geometrical framework, we show that it is also possible to relate the Local VC-Entropy to the Local Rademacher Complexity by finding an admissible range for one given the other. In addition, the Local VC-Entropy allows one to reduce the computational requirements that arise when dealing with the Local Rademacher Complexity in binary classification problems.     

Axonal mRNA localization and local translation in neurodegenerative diseases

The regulation of mRNA localization and local translation play vital roles in the maintenance of cellular structure and function.Many human neurodegenerative diseases,such as fragile X syndrome,amyotrophic lateral sclerosis,Alzheimer’s disease,and spinal muscular atrophy,have been characterized by pathological changes in neuronal axons,including abnormal mRNA translation,the loss of protein expression,or abnormal axon transport.Moreover,the same protein and mRNA molecules have been associated with variable functions in different diseases due to differences in their interaction networks.In this review,we briefly examine fragile X syndrome,amyotrophic lateral sclerosis,Alzheimer’s disease,and spinal muscular atrophy,with a focus on disease pathogenesis with regard to local mRNA translation and axon transport,suggesting possible treatment directions.     

Acute stroke trials: the problems of local investigators?

During stroke trials local investigators have to face many practical problems and time consuming procedures (filling in huge case report forms, performing repeat blood sample drawings for pharmacokinetic studies etc.) which, however, simply require organizational structures which is understood to be necessary to be able to conduct such kind of studies. Other, and most worrisome problems, are indeed to be solved when a sponsored research may rise potential ethical issues, or when academic research proposals clash with the interest of pharmaceutical companies or find difficulties in being funded by public institutions. It is just a greater involvement of these latter, possibly free from bureaucratic laces, which might help a balance to be struck between academic and industrial aims.     

Global versus local processing: Is there a hemispheric dichotomy?

A major dichotomy proposed for lateralized information processing is that the right and left cerebral hemispheres are "global" and "analytic" processors respectively. Here three experiments employed a tachistoscopic recognition paradigm with letter patterns varying in size and composition. No visual field asymmetries in RT were found in the first two experiments, although statistical power was high and a Stroop-like effect ("global precedence") was supported. Experiment 3 resulted in a right field advantage for vocal naming responses yet no asymmetry for manual responses, suggesting that both hemispheres can recognize global and local patterns, but that introduction of a laterally controlled response independently determines asymmetry.     

Microcirculation response to local cooling in patients with Huntington’s disease

Altered autonomic nervous system (ANS) functioning in early stages of Huntington's disease (HD) has been suggested, presumably due to distorted high-order autonomic control. ANS functioning in the early stages of HD was further investigated. Laser-Doppler (LD) flux in the skin of the fingertips, heart rate (HR), HR variability, systolic and diastolic blood pressure were measured during rest and during a 6 min cooling of one hand at 15°C. Data of 15 presymptomatic gene mutation carriers (PHD), 15 early symptomatic HD patients (EHD), and two groups of 15 age- and sex-matched controls were compared. The area under the low frequency (LF) and high frequency (HF) bands of the HR variability spectrum were calculated. An augmented reduction of cutaneous LD flux was found in response to the direct cooling in the PHD group (37.5 ± 8.5% of resting value) compared to the PHD controls (67.27 ± 8.4%) (p < 0.05). In addition, the PHD group had higher (LF/(LF + HF) index of primary sympathetic modulation of the HR at rest (53.6 ± 3.3) compared to the EHD patients (39.7 ± 4.2) (p < 0.05). In the EHD group, a significantly smaller change of HR during cooling (100.26 ± 1.2%) was found compared to the EHD controls (95.9 ± 1.0%) (p < 0.05). The results are in line with the hypothesis that ANS dysfunction occurs even in PHD subjects. Further, they support the hypothesis that dysfunction of the high-order autonomic centres are involved in HD.     

Health and education: service providers in partnership to improve mental health

Background

Children and adolescents from complex or disadvantaged backgrounds and multiple needs often are reluctant to seek help and this is particularly relevant in the context of mental health difficulties. Further, the complexity of the health system can be overwhelming to the family who are likely to be chaotic and less able to seek help. The current project piloted an integrated service delivery model involving a child psychiatry service and the department of education to promote access to mental health assessment and intervention to young people attending special education schools in Sydney, Australia.

Findings and conclusion

The project allowed improved access to mental health services for a group of young people who would otherwise not have sought help through traditional referral pathways. Our findings support strategies to promote the social milieu of schools as a way of achieving better mental health and learning outcomes.     

Prevalence of mental health disorders among low-income African American adolescents

Purpose

Data on the prevalence of mental health disorders for low-income, urban African American adolescents are scarce. This study presents data about the burden of mental disorders for this understudied population.

Methods

Mental disorders were assessed using the Diagnostic Interview Schedule for Children (C-DISC), Youth Self-Report (YSR), and Child Behavior Checklist (CBCL) among a sample of adolescents and their caregivers from very impoverished neighborhoods in a Southern city.

Results

Based on the C-DISC, 3.8, 5.1 and 7.7 % of adolescents met diagnostic criteria for major depression, post-traumatic stress disorder, and conduct disorder, respectively. There were significant differences among some of the mental health disorders based on adolescent and caregiver characteristics such as sex, school status, caregiver work status, and income level. We found a low prevalence of alcohol, marijuana, and substance abuse and dependence disorders.

Conclusions

Information about the prevalence of mental health disorders in specific communities and populations can assist in addressing unmet needs, planning for services and treatment, and reducing health disparities.     

Communal proactive coping strategies among Tamil refugees in Norway: A case study in a naturalistic setting

Background

Most adolescents live in resource-constrained countries and their mental health has been less well recognised than other aspects of their health. The World Health Organization's 4-S Framework provides a structure for national initiatives to improve adolescent health through: gathering and using strategic information; developing evidence-informed policies; scaling up provision and use of health services; and strengthening linkages with other government sectors. The aim of this paper is to discuss how the findings of a recent systematic review of mental health problems in adolescents in resource-constrained settings might be applied using the 4-S Framework.

Method

Analysis of the implications of the findings of a systematic search of the English-language literature for national strategies, policies, services and cross-sectoral linkages to improve the mental health of adolescents in resource-constrained settings.

Results

Data are available for only 33/112 [29%] resource-constrained countries, but in all where data are available, non-psychotic mental health problems in adolescents are identifiable, prevalent and associated with reduced quality of life, impaired participation and compromised development. In the absence of evidence about effective interventions in these settings expert opinion is that a broad public policy response which addresses direct strategies for prevention, early intervention and treatment; health service and health workforce requirements; social inclusion of marginalised groups of adolescents; and specific education is required. Specific endorsed strategies include public education, parent education, training for teachers and primary healthcare workers, psycho-educational curricula, identification through periodic screening of the most vulnerable and referral for care, and the availability of counsellors or other identified trained staff members in schools from whom adolescents can seek assistance for personal, peer and family relationship problems.

Conclusion

The predominant endorsed action is not that dedicated mental health services for adolescents are required, but that mental health care should be integrated using cross-sectoral strategies into the communities in which adolescents live, the institutions they attend and the organisations in which they participate.     

Service use in adolescents at risk of depression and self-harm: prospective longitudinal study

Purpose

Although depression and self-harm are common mental health problems in adolescents, there are barriers to accessing help. Using a community-based sample, this study investigates predictors of service contacts for adolescents at high risk of depression and self-harm.

Methods

Three thousand seven hundred and forty-nine (3,749) 12- to 16-year-olds in UK secondary (high) schools provided baseline and 6 months’ follow-up data on mood, self-harm and service contacts with a range of primary and secondary healthcare services.

Results

Although most adolescents at high risk of depression or self-harm had seen their general practitioner (GP) in the previous 6 months, less than one-third had used primary or secondary healthcare services for emotional problems. 5 % of adolescents who reported self-harm had seen specialist child and adolescent mental health services in the previous 6 months. In longitudinal analyses, after adjustment for confounders, both depression and self-harm predicted the use of any healthcare services [adjusted odds ratio (AOR) = 1.34 (95 % CI 1.09, 1.64); AOR = 1.38 (95 % CI 1.02, 1.86), respectively] and of specialist mental health services [AOR = 5.48 (95 % CI 2.27, 13.25); AOR = 2.58 (95 % CI 1.11, 6.00), respectively]. Amongst those with probable depression, 79 % had seen their GP and 5 % specialist mental health services in the preceding year.

Conclusions

Most adolescents at high risk of depression or self-harm see their GP over a 6-month period although only a minority of them access specialist mental health services. Their consultations within primary care settings provide a potential opportunity for their identification and for signposting to appropriate specialist services.     

The long-lasting impact of adolescents’ deviant friends on suicidality: a 3-year follow-up perspective

Background

During adolescence, friends are increasingly important for support and values. Do friends also have a long-term impact on suicidality? This study explored the role of friendship problems (e.g., social isolation) and deviant friends during late adolescence on suicidal ideation and behavior 3 years later.

Method

Participants were 295 community adolescents (59 % Mexican-American; 41 % European-American) from the United States. Information about their suicidal ideation and behavior, depression, friendship problems, and deviant friends was collected at baseline and at a 3-year follow-up.

Results

Having deviant friends was a better predictor of suicidality than having friendship problems, with variability by sex and ethnicity. Having deviant friends predicted suicidal ideation among Mexican-American adolescents. Having friends who were disconnected from school was a risk factor for suicidal ideation among European-American adolescents but a protective factor for suicidal behavior among Mexican-American adolescents, especially boys. Depression played more of a mediating role between friendship factors and suicidality for European-American than for Mexican-American adolescents.

Conclusions

This study’s findings suggest an influence of adolescents’ deviant friends on suicidality 3 years later. They also call for the cultural and gender grounding of suicide theory, research and prevention.     

Reasons for illicit drug use in people with schizophrenia: Qualitative study

Background

People who experience traumatic events have an increased risk of developing a range of mental disorders. Appropriate early support from a member of the public, whether a friend, family member, co-worker or volunteer, may help to prevent the onset of a mental disorder or may minimise its severity. However, few people have the knowledge and skills required to assist. Simple guidelines may help members of the public to offer appropriate support when it is needed.

Methods

Guidelines were developed using the Delphi method to reach consensus in a panel of experts. Experts recruited to the panels included 37 professionals writing, planning or working clinically in the trauma area, and 17 consumer or carer advocates who had been affected by traumatic events. As input for the panels to consider, statements about how to assist someone who has experienced a traumatic event were sourced through a systematic search of both professional and lay literature. These statements were used to develop separate questionnaires about possible ways to assist adults and to assist children, and panel members answered either one questionnaire or both, depending on experience and expertise. The guidelines were written using the items most consistently endorsed by the panels across the three Delphi rounds.

Results

There were 180 items relating to helping adults, of which 65 were accepted, and 155 items relating to helping children, of which 71 were accepted. These statements were used to develop the two sets of guidelines appended to this paper.

Conclusions

There are a number of actions which may be useful for members of the public when they encounter someone who has experienced a traumatic event, and it is possible that these actions may help prevent the development of some mental health problems in the future. Positive social support, a strong theme in these guidelines, has some evidence for effectiveness in developing mental health problems in people who have experienced traumatic events, but the degree to which it helps has not yet been adequately demonstrated. An evaluation of the effectiveness of these guidelines would be useful in determining their value. These guidelines may be useful to organisations who wish to develop or revise curricula of mental health first aid and trauma intervention training programs and policies. They may also be useful for members of the public who want immediate information about how to assist someone who has experienced a potentially traumatic event.     

Socio-cultural factors surrounding mental distress during the perinatal period in Zambia: a qualitative investigation

Background

The presence of mental distress during pregnancy and after childbirth imposes detrimental developmental and health consequences for families in all nations. In Zambia, the Ministry of Health (MoH) has proposed a more comprehensive approach towards mental health care, recognizing the importance of the mental health of women during the perinatal period.

Aim

The study explores factors contributing to mental distress during the perinatal period of motherhood in Zambia.

Methods

A qualitative study was conducted in Lusaka, Zambia with nineteen focus groups comprising 149 women and men from primary health facilities and schools respectively.

Findings

There are high levels of mental distress in four domains: worry about HIV status and testing; uncertainty about survival from childbirth; lack of social support; and vulnerability/oppression.

Conclusion

Identifying mental distress and prompt referral for interventions is critical to improving the mental health of the mother and prevent the effects of mental distress on the baby.

Recommendation

Strategies should be put in place to ensure pregnant women are screened for possible perinatal mental health problems during their visit to antenatal clinic and referral made to qualified mental health professionals. In addition further research is recommended in order to facilitate evidence based mental health policy formulation and implementation in Zambia.     

Suicidal behaviours in adolescents in Nova Scotia, Canada: protective associations with measures of social capital

Purpose

Few studies of adolescent suicidality have examined its associations with social capital. We explored associations of measures of individual level social capital with self-reported suicide ideation and suicide attempt in adolescents in Cape Breton, Nova Scotia, Canada, controlling for other factors known to be associated with adolescent suicidality.

Methods

We surveyed 1,597 grade 10–12 students at three high schools in 2006 using self-completion questionnaires. Both sexes were combined for analysis. Outcome measures were suicidal ideation and attempt in the previous year. Measures of social capital included perceptions of trustworthiness and helpfulness of others at school, frequency of religious attendance and participation in extracurricular activities. Logistic regressions were carried out to determine associations of social capital with suicidality while controlling for other factors.

Results

Perceived trustworthiness and helpfulness were protective for suicidal ideation and suicide attempt in the previous year. In adjusted analyses, there were interactions of gender and social capital—females reporting more social capital were more protected from suicide attempt relative to males with similar levels of social capital.

Conclusions

This study provides initial evidence of protective associations of individual level social capital with adolescent suicidality. Our findings suggest that among adolescents low social capital as measured by perceptions of trust and helpfulness of others at school may be a warning sign for suicidality, particularly for females. It may be helpful to inquire of young people how they perceive the trustworthiness and helpfulness of their school environment as a measure of how supportive that environment might be to them when they are facing challenges to their mental health.     

Nonsuicidal self-harm and suicide attempts in adolescents: differences in kind or in degree?

Purpose

The purpose of the present study was to measure the prevalence of self-harm (SH) behaviours and examine potential differences in characteristics among adolescents reporting on self-harm (SH), depending on whether they had attempted suicide (SA), performed nonsuicidal self-harm (NSSH), or both.

Methods

Cross-sectional survey of 11,440 adolescents aged 14–17 years in the city of Oslo, Norway. Responses regarding measures of lifetime SH and risk factors were collected. The response rate was 92.7 %. Data were analysed by segregating SH responses into the categories of NSSH, SA, and NSSH + SA.

Results

Among all respondents, 4.3 % reported NSSH, 4.5 % reported SA, 5.0 % reported both NSSH and SA, and 86.2 % reported no SH. The group reporting to have engaged in both behaviours comprised more girls and reported more suicidal ideation, problematic lifestyles, poorer subjective health, and more psychological problems compared with the other groups. The four groups could be distinguished by one discriminant function that accounted for most of the explained variance.

Conclusions

Our findings suggest that NSSH and SA are parts of the same dimensional construct in which suicidal ideation carries much of the weight in adolescents from a school-based sample. They also indicate the group of adolescents who seems to alternate between NSSH and SA is more burdened with mental ill-health and behavioural problems compared with others. These adolescents should therefore be targeted by clinicians and school health personnel for identification and provision of adequate help and services.     

A real-life observational study of the effectiveness of FACT in a Dutch mental health region

Background

Suicide is a statistically rare event, but devastating to those left behind and one of the worst possible outcomes associated with mental illness. Although a friend, family member or co-worker may be the first person to notice that a person is highly distressed, few have the knowledge and skills required to assist. Simple guidelines may help such a person to encourage a suicidal individual to seek professional help or decide against suicide.

Methods

This research was conducted using the Delphi methodology, a method of reaching consensus in a panel of experts. Experts recruited to the panels included 22 professionals, 10 people who had been suicidal in the past and 6 carers of people who had been suicidal in the past. Statements about how to assist someone who is thinking about suicide were sourced through a systematic search of both professional and lay literature. The guidelines were written using the items most consistently endorsed by all three panels.

Results

Of 114 statements presented to the panels, 30 were accepted. These statements were used to develop the guidelines appended to this paper.

Conclusion

There are a number of actions which are considered to be useful for members of the public when they encounter someone who is experiencing suicidal thoughts or engaging in suicidal behaviour. These guidelines will be useful in revision of curricula of mental health first aid and suicide intervention training programs. They can also be used by members of the public who want immediate information about how to assist a suicidal person.