Positive lifestyle behaviours and emotional health factors are associated with low back pain resilience.

PURPOSE: To evaluate the relationship between lifestyle behaviours, emotional health factors, and low back pain (LBP) resilience. METHODS: This retrospective longitudinal study utilised 1,065 twins with a recent history of LBP from the Washington State Twin Registry. A lifestyle behaviour score was built using variables of body mass index, physical activity engagement, sleep quality, smoking status, and alcohol consumption. An emotional health score was built using variables of the absence of depressed mood, perceived stress, and active coping. The main outcome was LBP resilience, assessed as recovery ("bouncing back"), and sustainability (maintaining high levels of function despite LBP). RESULTS: After adjusting for covariates, there was no relationship between the lifestyle behaviour score (OR 1.05, 95% CI 0.97-1.15, p = 0.218) and the emotional health score (OR 1.08, 95% CI 0.98-1.19, p = 0.142) with the likelihood of recovering from LBP. There was however, evidence of a positive association between the lifestyle behaviour score (ß 0.20, 95% CI 0.04-0.36, p = 0.013), the emotional health score (ß 0.22, 95% CI 0.00-0.43, p = 0.049), and greater levels of sustainability. These results were confirmed by a within-pair analysis (lifestyle behaviour score: ß 1.79, 95% CI 0.05-3.53, p = 0.043) and (emotional health score: ß 0.52, 95% CI 0.09-0.96, p = 0.021) adjusting for genetic and early shared environmental confounding. CONCLUSION: Findings from this study suggest that people who adopt optimal lifestyle behaviours and positive emotional factors are more likely to be resilient and maintain high levels of function despite suffering from LBP.

Acculturation, resilience, and the mental health of migrant youth: a cross-country comparative study.

OBJECTIVES: Using data from an international collaborative research project on youth resilience in the context of migration, this study aims to investigate how different acculturation patterns (i.e. integration, assimilation, separation and marginalization) influence the mental health of migrant youth, and whether resilience might function as a mediator in the association between acculturation and mental health. STUDY DESIGN: A cross-sectional pilot study conducted in six countries employing a common survey questionnaire. METHODS: The study sample was 194 youths aged 10-17 years (median = 13.6) from six countries (Australia, Canada, China, New Zealand, South Africa, and United Kingdom) and included cross-border and internal migrants. Mental health and well-being was measured by the Warwick-Edinburgh Mental Well-Being Scale (WEMWBS). Resilience was measured by the Child and Youth Resilience Measure-28 (CYRM-28). Acculturation was assessed using the Acculturation, Habits, and Interests Multicultural Scale for Adolescents (AHIMSA). Multivariate regression and path analysis were performed to examine the hypothesized mediation model. RESULTS: Resilience scores correlated strongly with mental health and well-being. Acculturation exerted no significant direct effects on the mental health of migrant youths. Nevertheless, compared to youths who were integration-oriented, assimilation-oriented youths tended to exhibit lower levels of resilience, resulting in poorer mental health. Compared to youths from other countries, migrant youths from China also reported lower levels of resilience, which led to poorer mental health outcome. CONCLUSION: Acculturation plays a significant role in the mental health of migrant youth, with different acculturative orientations exhibiting different influences through the mediation effect of resilience. Fostering resilience and facilitating integration-oriented acculturation are recommended public health strategies for migrant youth.

Quantifying person-level brain network functioning to facilitate clinical translation.

Although advances in neuroimaging have yielded insights into the intrinsic organization of human brain networks and their relevance to psychiatric and neurological disorders, there has been no translation of these insights into clinical practice. One necessary step toward clinical translation is identifying a summary metric of network function that is reproducible, reliable, and has known normative data, analogous to normed neuropsychological tests. Our aim was therefore to establish the proof of principle for such a metric, focusing on the default mode network (DMN). We compared three candidate summary metrics: global clustering coefficient, characteristic path length, and average connectivity. Across three samples totaling 322 healthy, mostly Caucasian adults, average connectivity performed best, with good internal consistency (Cronbach's α=0.69-0.70) and adequate eight-week test-retest reliability (intra-class coefficient=0.62 in a subsample N=65). We therefore present normative data for average connectivity of the DMN and its sub-networks. These proof of principle results are an important first step for the translation of neuroimaging to clinical practice. Ultimately, a normed summary metric will allow a single patient's DMN function to be quantified and interpreted relative to normative peers.

Interactions between BDNF Val66Met polymorphism and early life stress predict brain and arousal pathways to syndromal depression and anxiety.

Individual risk markers for depression and anxiety disorders have been identified but the explicit pathways that link genes and environment to these markers remain unknown. Here we examined the explicit interactions between the brain-derived neurotrophic factor (BDNF) Val66Met gene and early life stress (ELS) exposure in brain (amygdala-hippocampal-prefrontal gray matter volume), body (heart rate), temperament and cognition in 374 healthy European volunteers assessed for depression and anxiety symptoms. Brain imaging data were based on a subset of 89 participants. Multiple regression analysis revealed main effects of ELS for body arousal (resting heart rate, P=0.005) and symptoms (depression and anxiety, P<0.001) in the absence of main effects for BDNF. In addition, significant BDNF-ELS interactions indicated that BDNF Met carriers exposed to greater ELS have smaller hippocampal and amygdala volumes (P=0.013), heart rate elevations (P=0.0002) and a decline in working memory (P=0.022). Structural equation path modeling was used to determine if this interaction predicts anxiety and depression by mediating effects on the brain, body and cognitive measures. The combination of Met carrier status and exposure to ELS predicted reduced gray matter in hippocampus (P<0.001), and associated lateral prefrontal cortex (P<0.001) and, in turn, higher depression (P=0.005). Higher depression was associated with poorer working memory (P=0.005), and slowed response speed. The BDNF Met-ELS interaction also predicted elevated neuroticism and higher depression and anxiety by elevations in body arousal (P<0.001). In contrast, the combination of BDNF V/V genotype and ELS predicted increases in gray matter of the amygdala (P=0.003) and associated medial prefrontal cortex (P<0.001), which in turn predicted startle-elicited heart rate variability (P=0.026) and higher anxiety (P=0.026). Higher anxiety was linked to verbal memory, and to impulsivity. These effects were specific to the BDNF gene and were not evident for the related 5HTT-LPR polymorphism. Overall, these findings are consistent with the correlation of depression and anxiety, yet suggest that partially differentiated gene-brain cognition pathways to these syndromes can be identified, even in a nonclinical sample. Such findings may aid establishing an evidence base for more tailored intervention strategies.

Investigation of MCPH1 G37995C and ASPM A44871G polymorphisms and brain size in a healthy cohort.

Loss-of-function mutations in MCPH1 and ASPM are responsible for some cases of autosomal recessive primary microcephaly. Recent studies have indicated that certain common variants of these genes have been positively selected for during the evolution of modern humans. It is therefore possible that these variants may predispose to an increase in brain size in the normal human population. We genotyped the MCPH1 G37995C and ASPM A44871G polymorphisms in a cohort of 118 healthy people who had undergone structural magnetic resonance imaging analysis. We did not detect significant association of either MCPH1 G37995C or ASPM A44871G genotype with whole brain volume, cerebral cortical volume or proportion of grey matter in this cohort. Nor did we detect an association of combined MCPH1 37995C and ASPM 44871G allele dosage with these brain measurements. These results were also confirmed in an age-restricted subcohort of 94 individuals. This study suggests that phenotypes other than brain size may have been selected for in ASPM and MCPH1 variants during evolution of modern humans.

The contribution of apolipoprotein E alleles on cognitive performance and dynamic neural activity over six decades.

Neuroimaging shows brain-functional differences due to apolipoprotein E (APOE) polymorphisms may exist decades before the increased risk period for Alzheimer's disease, but little is known about their effect on cognition and brain function in children and young adults. This study assessed 415 healthy epsilon2 and epsilon4 carriers and matched epsilon3/epsilon3 controls, spanning ages 6-65, on a range of cognitive tests. Subjects were also compared on a new dynamical measure of EEG activity during a visual working memory task using alphabetical stimuli. epsilon4 subjects had better verbal fluency compared to epsilon3, an effect that was strongest in 51-65 year-olds. No epsilon4 deficits in cognition were found. In 6-15 year-olds, there were differences in total spatio-temporal wave activity between epsilon3 and epsilon4 subjects in the theta band, approximately 200ms post-stimulus. Differences in brain function in younger epsilon4 subjects and superior verbal fluency across the entire age range suggest that the APOE epsilon4 allele is an example of antagonistic pleiotropy.

Elastic properties of composites: periodical homogenisation technique and experimental comparison using acoustic microscopy and resonant ultrasonic spectroscopy.

The macroscopic elastic properties of two composites (Duralumin/air and Duralumin/tungsten carbide (WC)) have been calculated using periodical homogenisation methods and the elastic properties of each phase (measured by high frequency acoustic microscopy). In order to check the validity of such an approach, acoustical resonant spectroscopy has also been applied. Thanks to the comparison between the resonant frequencies predicted and measured, two major conclusions have been obtained: the homogenisation method is very accurate for the composite Duralumin/air, but not for the Duralumin/WC sample: the experimental results are not in very good agreement with the simulation. This result can be then explained by the major role of interfacial state between Duralumin and tungsten carbide.