Recurrent canards producing relaxation oscillations

For three three-dimensional chaotic systems (Sprott NE1, NE8, and NE9) with only linear and quadratic terms and one parameter, but without equilibria, we consider the second order asymptotic approximations in the case that the parameter is small and near the origin of phase-space. The calculation leads to the existence and approximation of periodic solutions with neutral stability for systems NE1, NE9, and asymptotic stability for system NE8. Extending to a larger neighborhood in phase-space, we find a new type of relaxation oscillations with pulse behavior that can be understood by identifying hidden canards. The relaxation dynamics coexists with invariant tori and chaos in the systems.

Religiosity and mental health of pre-adolescents with psychiatric problems and their parents: The TRAILS study

Background:

This study investigated the association between the religiosity of parents and pre-adolescents, and pre-adolescents’ psychiatric problems.

Method:

In a clinic-referred cohort of 543 pre-adolescents at least once referred to a mental health outpatient clinic mental health problems were assessed using self-reports (Youth Self-Report; YSR), parent reports (Child Behavior Checklist; CBCL), and teacher reports (Teacher's Report Form; TRF) of child behavioral and emotional problems. Paternal, maternal, and pre-adolescent religiosity were assessed by self-report. MANCOVAs were performed for internalizing and externalizing problems as dependent variables, with maternal religiosity, paternal religiosity, pre-adolescent religiosity, parental religious harmony, and gender as independent variables, and socioeconomic status and divorce as covariates.

Results:

Internalizing problems. Pre-adolescents of actively religious mothers had more internalizing symptoms than pre-adolescents of nonreligious mothers. Harmony and gender did not significantly affect the association between maternal religiosity and internalizing problems. Externalizing problems. No associations between religiosity of pre-adolescents, religiosity of mothers, religiosity of fathers and/or harmony of parents and externalizing problem behavior have been found.

Discussion and conclusions:

Overall, associations between mental health and religiosity were modest to absent. Results are discussed in the context of a clinic-referred cohort, the quest phase of internalizing religious beliefs and role modeling of parents.

Managing the link and strengthening transition from child to adult mental health Care in Europe (MILESTONE): background, rationale and methodology

BACKGROUND

Transition from distinct Child and Adolescent Mental Health (CAMHS) to Adult Mental Health Services (AMHS) is beset with multitude of problems affecting continuity of care for young people with mental health needs. Transition-related discontinuity of care is a major health, socioeconomic and societal challenge globally. The overall aim of the Managing the Link and Strengthening Transition from Child to Adult Mental Health Care in Europe (MILESTONE) project (2014-19) is to improve transition from CAMHS to AMHS in diverse healthcare settings across Europe. MILESTONE focuses on current service provision in Europe, new transition-related measures, long term outcomes of young people leaving CAMHS, improving transitional care through 'managed transition', ethics of transitioning and the training of health care professionals.

METHODS

Data will be collected via systematic literature reviews, pan-European surveys, and focus groups with service providers, users and carers, and members of youth advocacy and mental health advocacy groups. A prospective cohort study will be conducted with a nested cluster randomised controlled trial in eight European Union (EU) countries (Belgium, Croatia, France, Germany, Ireland, Italy, Netherlands, UK) involving over 1000 CAMHS users, their carers, and clinicians.

DISCUSSION

Improving transitional care can facilitate not only recovery but also mental health promotion and mental illness prevention for young people. MILESTONE will provide evidence of the organisational structures and processes influencing transition at the service interface across differing healthcare models in Europe and longitudinal outcomes for young people leaving CAMHS, solutions for improving transitional care in a cost-effective manner, training modules for clinicians, and commissioning and policy guidelines for service providers and policy makers.

TRIAL REGISTRATION

"MILESTONE study" registration: ISRCTN ISRCTN83240263 Registered 23 July 2015; ClinicalTrials.gov NCT03013595 Registered 6 January 2017.

Gestational vitamin D deficiency and autism-related traits: the Generation R Study

There is intense interest in identifying modifiable risk factors associated with autism-spectrum disorders (ASD). Autism-related traits, which can be assessed in a continuous fashion, share risk factors with ASD, and thus can serve as informative phenotypes in population-based cohort studies. Based on the growing body of research linking gestational vitamin D deficiency with altered brain development, this common exposure is a candidate modifiable risk factor for ASD and autism-related traits. The association between gestational vitamin D deficiency and a continuous measure of autism-related traits at ~6 years (Social Responsiveness Scale; SRS) was determined in a large population-based cohort of mothers and their children (n=4229). 25-hydroxyvitamin D (25OHD) was assessed from maternal mid-gestation sera and from neonatal sera (collected from cord blood). Vitamin D deficiency was defined as 25OHD concentrations less than 25 nmol l^-1. Compared with the 25OHD sufficient group (25OHD>50 nmol l^-1), those who were 25OHD deficient had significantly higher (more abnormal) SRS scores (mid-gestation n=2866, β=0.06, P<0.001; cord blood n=1712, β=0.03, P=0.01). The findings persisted (a) when we restricted the models to offspring with European ancestry, (b) when we adjusted for sample structure using genetic data, (c) when 25OHD was entered as a continuous measure in the models and (d) when we corrected for the effect of season of blood sampling. Gestational vitamin D deficiency was associated with autism-related traits in a large population-based sample. Because gestational vitamin D deficiency is readily preventable with safe, cheap and accessible supplements, this candidate risk factor warrants closer scrutiny.

Familial confounding of the association between maternal smoking during pregnancy and internalizing disorders in offspring

BACKGROUND

Maternal smoking has consistently been associated with multiple adverse childhood outcomes including externalizing disorders. In contrast the association between maternal smoking during pregnancy (MSDP) and internalizing (anxiety and depressive) disorders in offspring has received less investigation.

METHOD

We conducted a nationwide cohort study including 957635 individuals born in Denmark between 1991 and 2007. Data on MSDP and diagnoses of depression or anxiety disorders were derived from national registers and patients were followed up from the age of 5 years to the end of 2012. Hazard rate ratios (HRRs) were estimated using stratified Cox regression models. Sibling data were used to disentangle individual- and familial-level effects of MSDP and to control for unmeasured familial confounding.

RESULTS

At the population level, offspring exposed to MSDP were at increased risk for both severe depression [HRR 1.29, 95% confidence interval (CI) 1.22-1.36] and severe anxiety disorders (HRR 1.26, 95% CI 1.20-1.32) even when controlling for maternal and paternal traits. However, there was no association between MSDP and internalizing disorders when controlling for the mother's propensity for MSDP (depression: HRR 1.11, 95% CI 0.94-1.30; anxiety disorders: HRR 0.94, 95% CI 0.80-1.11) or comparing differentially exposed siblings (depression: HRR 1.18, 95% CI 0.75-1.89; anxiety disorders: HRR 0.87, 95% CI 0.55-1.36).

CONCLUSIONS

The results suggest that familial background factors account for the association between MSDP and severe internalizing disorders not the specific exposure to MSDP.

[Supporting patients in self-management: moving to a personalised approach]

OBJECTIVE

The aim of this research was to assess the effect of providing personalised self-management support on patient activation (knowledge, skills, self-efficacy) and self-management behaviour.

DESIGN

Cluster randomised trial in 15 general practices (Dutch Trial Register No.: NTR 3960).

METHOD

Patients aged 18 years or older with a chronic condition were invited to participate in the study. The Self-Management Screening (SeMaS) questionnaire - which illustrates barriers to self-management - was used as a tool for personalised self-management support. Nurse practitioners in the intervention practices were trained for 2 hours in using SeMaS and personalising self-management support on the basis of the SeMaS profile. At baseline and after 6 months, patients filled in questionnaires on patient activation (PAM-13) and lifestyle. Using data from the questionnaires and medical records, the use of individual care plans, referrals to self-management interventions, self-monitoring and healthcare use were assessed. We used a multiple multilevel regression model for data analysis.

RESULTS

After 6 months, no difference was found in patient activation between the control group (n = 348) and the intervention group (n = 296). 29.4% of the patients in the intervention group performed self-monitoring, versus 15.2% in the control group (regression coefficient r = 0.9, p = 0.01). In the per-protocol analysis (control n = 348; intervention n = 136), the number of individual care plans (r = 1.3, p = 0.04) and the number of patients performing self-monitoring (r = 1.0; p = 0.01) were higher in the intervention group.

CONCLUSION

Personalised self-management support with the use of the SeMaS method stimulates self-monitoring and the use of individual care plans. The intervention had no effect on patient activation or lifestyle. Given the positive secondary outcomes, the further potential of the tool should be researched.

Physical activity and onset of depression in adolescents: a prospective study in the general population cohort TRAILS

Although it has often been suggested that physical activity and depression are intertwined, only few studies have investigated whether specific aspects of physical activity predict the incidence of major depression in adolescents from the general population. Therefore the aim of this study was to investigate the effects of nature, frequency, duration and intensity of physical activity during early adolescence on the onset of a major depressive episode in early adulthood. In a population sample of adolescents (N = 1396), various aspects of physical activity were assessed at early adolescence (mean age 13.02, SD = 0.61). Major depressive episode onset was assessed using the Composite International Diagnostic Interview. A Cox regression model was performed to investigate whether physical activity characteristics and their interactions with gender predicted a major depressive episode onset up until mean age 18.5 (SD = 0.61). The individual characteristics of physical activity (nature, frequency, duration and intensity) or their interactions with gender did not predict a major depressive episode onset (p values >0.05). So far, there is no prospective evidence that physical activity protects against the development of adolescent depressive episodes in either boys or girls.

DRD2 and DRD4 in relation to regular alcohol and cannabis use among adolescents: does parenting modify the impact of genetic vulnerability? The TRAILS study

AIMS

The aims of the present study were to determine the direct effect of DRD2 and DRD4, as well as their interaction with parenting (i.e. rejection, overprotection and emotional warmth), on the development of regular alcohol and cannabis use in 1192 Dutch adolescents from the general population.

METHODS

Information was obtained by self-report questionnaires. Perceived rejection, overprotection and emotional warmth were assessed at age 10-12. Regular alcohol and cannabis use were determined at age 15-18 and defined as the consumption of alcohol on 10 or more occasions in the past four weeks, and the use of cannabis on 4 or more occasions in the past four weeks. Models were adjusted for age, sex, parental alcohol or cannabis use, and externalizing behavior.

RESULTS

Carrying the A1 allele of the DRD2 TaqIA polymorphism, or the 7 repeat DRD4, was not directly related to regular alcohol or cannabis use. In addition, adolescent carriers of these genetic risk markers were not more susceptible to the influence of less optimal parenting. Main effects for parenting indicated that overprotection increased the risk of regular alcohol use, whereas the risk of cannabis use was enhanced by parental rejection and buffered by emotional warmth.

CONCLUSIONS

Our findings do not support an association between DRD2/DRD4 and regular alcohol and cannabis use in adolescents. Given the substance-specific influences of rejection, overprotection and emotional warmth, these parenting factors might be promising candidates for prevention work.

Child to adult continuities of psychopathology: a 24-year follow-up

OBJECTIVE

To determine continuities of mental health problems of children across a 24-year follow-up period.

METHOD

In 1983, parent ratings of emotional and behavioral problems were collected with the Child Behavior Checklist (CBCL) in a general population sample of 2076 children. Twenty-four years later, 1365 participants completed Adult Self-Reports (ASR) to assess emotional and behavioral problems.

RESULTS

Of the participants who were classified as deviant in childhood, 22.2% were also classified as deviant in adulthood. Both homotypic and heterotypic continuity was found. Childhood aggressive, delinquent, and anxious/depressed problems were associated with most adult psychopathology. Attention problems did not predict later problems independently.

CONCLUSION

Even though assessed with parent-reports in childhood and analogous self-reports in adulthood, and over a large period of 24 years, continuity of psychopathology was found from childhood into adulthood. Anxious/depressed problems, delinquent behavior and aggressive behavior in childhood are core predictors for adult psychopathology.

Diagnostic outcome of self-reported hallucinations in a community sample of adolescents

OBJECTIVE

We aimed to assess the diagnostic outcome of self-reported hallucinations in adolescents from the general population.

METHOD

The sample consisted of 914 adolescents between ages 11-18 participating in an ongoing longitudinal study. The participation rate from the original sample was 70%. Responses on the Youth Self-Report questionnaire were used to ascertain hallucinations in adolescents. Eight years later, Axis 1 DSM-IV diagnoses were assessed using the 12-month version Composite International Diagnostic Interview in 783 (86%) of 914 study subjects. No subjects were diagnosed with schizophreniform disorders or schizophrenia.

RESULTS

Hallucinations were reported by 6% of adolescents and 3% of young adults. Self-reported hallucinations were associated with concurrent non-psychotic psychiatric problems in both age groups. Adolescents who reported auditory, but not visual, hallucinations, had higher rates of depressive disorders and substance use disorders, but not psychotic disorders, at follow-up, compared to controls.

CONCLUSIONS

Self-reported auditory hallucinations in adolescents are markers of concurrent and future psychiatric impairment due to non-psychotic Axis 1 disorders and possibly Axis 2 disorders. It cannot be excluded that there was selective attrition of children and adolescents who developed Schizophrenic or other psychotic disorders later in life.

Outcome of self-reported functional-somatic symptoms in a community sample of adolescents

It is unclear if functional-somatic symptoms in adolescents increase the risk for future psychiatric disorders. Therefore, the outcome and continuity of adolescent self-reported functional-somatic symptoms in young adulthood were assessed. Self-reported data on functional-somatic symptoms from an ongoing epidemiological study in children started in 1983 were analyzed. Participants were adolescents aged 11-18 who filled out standardized questionnaires in 1989 and 1991 and who were reassessed in 1997 when they were young adults between ages 19 and 26. Outcome measures were research psychiatric diagnoses and self-reported functional-somatic symptoms in 1997. Functional-somatic symptoms were associated with other measures of psychopathology in adolescents. Adolescents with specific functional-somatic symptoms tended to report the same symptom along with other symptoms at follow-up. Adolescent self-reported functional-somatic symptoms did not increase the risk for future psychiatric disorders. Young adults with functional-somatic complaints were diagnosed more often than controls with depressive disorders and anxiety disorders, but not with antisocial personality disorders and substance use disorders. Adolescent self-reported functional-somatic symptoms were common and enduring but were not predictive for psychiatric disorders in young adulthood. Adolescents and young adults who complain of multiple functional-somatic complaints should be assessed for the presence of a psychiatric disorder particularly depression or anxiety.

A cross cultural comparison of French and Dutch disturbed children using the Child Behaviour Checklist (CBCL)

Parents, mostly mothers, of French and Dutch children who had been referred to Mental Health Services, completed the CBCL to indicate the behaviour problems that their children suffered from. The 85 items which had been found in the USA to measure eight types of disturbed behaviour, called the cross-informant syndromes, were studied to see if a similar set of dimensions of disturbed behaviour would underlie the Dutch and French CBCL scores. Seven types of disturbance were found which corresponded to the equivalent cross informant syndromes, but thought problems had no similar sort of disorder amongst the Dutch and French children. It was found that only 43 items were necessary to measure these seven dimensions. It was concluded that despite differences in language, culture and the pattern of mental health services, the CBCL scores could be used to make meaningful clinical comparisons of psychiatric disturbances.

[Behavioral symptoms of children and adolescents in Germany, the Netherlands and USA. A cross-cultural study with the Child Behavior Checklist]

The goal of the study was a cross-cultural comparison of the parent ratings of behavior problems of children and adolescents aged 4-18 years in Germany, The Netherlands and the United States using the Child Behavior Checklist (CBCL). The analyses were undertaken in a German community sample (n = 1622) and a Dutch community sample (n = 2076). The results were compared with the data published by Achenbach for the national US sample. The analyses were based on the scales of the 1991 CBCL version and were performed for four age and sex groups (4- to 11-year-old boys/girls and 12- to 18-year-old boys/girls). In general, relatively minor differences could be detected between the three random samples. The range in the different samples was between -0.04 and 0.35, which is in line with other cross-cultural analyses using the CBCL. As long as no representative norms for Germany are available, the American norms can serve as an orientation for German studies using the CBCL.