[Mindfulness based interventions for children and adolescents]. / Interventions basées sur la pleine conscience pour les enfants et les adolescents.

Mindfulness based interventions (MBI) are widely available to adults. Programs are also offered to children and adolescents. Interventions in school and clinical settings are increasingly being published in scientific literature. In the school context, the effects are promising on psychological health, such as stress, anxiety, depression or externalized behaviours, and on executive functions, attention, and socio-emotional skills. In the clinical context, MBI has a particular effect on stress/anxiety and depression as well as on the key symptoms of Attention Deficit Hyperactivity Disorder. These results are very encouraging, but all meta-analyses and literature reviews nevertheless emphasize the need for studies with robust methodology before proposing MBI on a large scale for this population.

Les interventions basées sur la pleine conscience (MBI) sont de plus en plus proposées aux enfants et aux adolescents et font l'objet de nombreuses publications scientifiques. Dans le contexte scolaire, les effets sont prometteurs sur la santé psychologique, comme le stress, l'anxiété, la dépression ou les comportements externalisés et sur les fonctions exécutives, l'attention, et les compétences socioémotionnelles. Dans le contexte clinique, les MBI ont un effet en particulier sur le stress/l'anxiété et la dépression ainsi que sur les symptômes clés du trouble du déficit d'attention avec hyperactivité. Ces résultats sont très encourageants mais toutes les méta-analyses et les revues de la littérature soulignent néanmoins la nécessité de faire des études à la méthodologie robuste avant de proposer des MBI à large échelle.

Sex-specific interactions between stress axis and redox balance are associated with internalizing symptoms and brain white matter microstructure in adolescents.

Adolescence is marked by the maturation of systems involved in emotional regulation and by an increased risk for internalizing disorders (anxiety/depression), especially in females. Hypothalamic-pituitary-adrenal (HPA)-axis function and redox homeostasis (balance between reactive oxygen species and antioxidants) have both been associated with internalizing disorders and may represent critical factors for the development of brain networks of emotional regulation. However, sex-specific interactions between these factors and internalizing symptoms and their link with brain maturation remain unexplored. We investigated in a cohort of adolescents aged 13-15 from the general population (n = 69) whether sex-differences in internalizing symptoms were associated with the glutathione (GSH)-redox cycle homeostasis and HPA-axis function and if these parameters were associated with brain white matter microstructure development. Female adolescents displayed higher levels of internalizing symptoms, GSH-peroxidase (GPx) activity and cortisol/11-deoxycortisol ratio than males. There was a strong correlation between GPx and GSH-reductase (Gred) activities in females only. The cortisol/11-deoxycortisol ratio, related to the HPA-axis activity, was associated with internalizing symptoms in both sexes, whereas GPx activity was associated with internalizing symptoms in females specifically. The cortisol/11-deoxycortisol ratio mediated sex-differences in internalizing symptoms and the association between anxiety and GPx activity in females specifically. In females, GPx activity was positively associated with generalized fractional anisotropy in widespread white matter brain regions. We found that higher levels of internalizing symptoms in female adolescents than in males relate to sex-differences in HPA-axis function. In females, our results suggest an important interplay between HPA-axis function and GSH-homeostasis, a parameter strongly associated with brain white matter microstructure.

Randomized controlled trial of a mindfulness-based intervention in adolescents from the general population: The Mindfulteen neuroimaging study protocol.

AIM: Adolescence is a period of vulnerability to stress. Increased anxiety during this period has been associated with the later development of mental disorders, hence the growing interest for interventions that could decrease stress reactivity and improve cognitive control in adolescents. Mindfulness-based interventions have demonstrated their efficacy on stress reactivity and anxiety in adults, but evidence is lacking in youth. METHODS: The Mindfulteen Study is a 3-year longitudinal cohort with a nested randomized controlled trial examining the effectiveness of mindfulness-based interventions for adolescents. Young adolescents from the general population, aged between 13 and 15 years old, with no history of current mental health disorder (apart from past mood disorders or current anxiety disorders) are included and stratified into low or high anxiety based on trait anxiety scores before being randomized to early or late 8-week intervention groups. Primary outcomes are based on neuroimaging data (i.e., structural and functional measures in the cortico-limbic network) while secondary outcomes are psychological (i.e., anxiety and stress-associated dimensions) and biological (i.e., cortisol, inflammatory and redox markers). Assessments are performed at baseline, immediately after intervention or waiting time and after 18 months of intervention. CONCLUSION: To the best of our knowledge, this is the first randomized controlled trail examining the effect of a mindfulness-based intervention in young adolescents from the general population based on the measurement and analyses of psychological, neuroimaging and biological data.