Strengthening the evidence on the association of language difficulties with mental health problems across childhood and adolescence

精神障碍是欧洲青年发病的主要原因。重要的是，约47%的青少年因心理健康问题症状而获得帮助，他们有中度至重度的语言困难，原因不明，即，与遗传或神经起源的复杂损伤无关，如唐氏综合症或智力残疾。此外，平均每30名学生中就有3名存在严重的语言困难，影响到他们的学习和社会情感发展。鉴于心理治疗是建立在复杂语言的产生和理解的基础上的，需要帮助的儿童可能最不能从中受益，因此必须了解为什么语言困难和精神障碍如此频繁地同时发生。语言障碍是否会导致精神障碍，或者它们的共同发生是否可以用其他风险因素（如共同基因或环境逆境）来解释？LaMMHa项目将利用现有的基于人口的研究，采用创新的流行病学方法，了解解释儿童和青少年语言困难与精神障碍之间联系的生物-心理-社会机制。它包括三个互补的目标：1）调查性质（相关性、因果性、双向性）研究语言困难与儿童期和青少年期精神障碍之间的关系。2）研究语言困难是否是解释早期心理社会逆境与精神健康问题之间关系的中介因素。3）确定语言困难和精神障碍之间可预防的心理社会途径。该项目将产生强有力的证据，具有在临床工作和预防中转化的潜力，并将为该研究员在严重缺乏专家的领域领导未来的流行病学研究做好准备。

Mental disorders are the leading causes of morbidity among youth in Europe. Critically, about 47% of youth accessing help for symptoms of mental health problems have moderate to severe language difficulties of unknown origin, i.e., not related with complex impairments of genetic or neurological origins such as Down syndrome or intellectual disabilities. Moreover, an average of 3 out of 30 pupils in a class, present language difficulties severe enough to affect their learning and socioemotional development. Given psychological therapies are grounded in the production and understanding of complex language - the very children who need help might be least able to benefit from it. It is thus imperative to understand why language difficulties and mental disorders co-occur so frequently. Do language difficulties cause mental disorders or can their co-occurrence be explained by other risk factors such as shared genes or environmental adversity? Drawing on existing population-based studies, the LaMMHa project will use innovative epidemiological methods to understand the bio-psycho-social mechanisms that explain the association between language difficulties and mental disorders in children and adolescents. It comprises of three complementary objectives: 1) to investigate the nature (correlational, causal, bidirectional) of the association between language difficulties and mental disorders in childhood and adolescence using longitudinal data from twin pairs 2) to investigate if language difficulties are a mediating factor explaining the association of early psychosocial adversity with mental health problems using causal mediation models; 3) to identify preventable psychosocial pathways linking language difficulties and mental disorders. The project will produce robust evidence with potential for translation in clinical work and prevention and will prepare the fellow to lead future epidemiological studies in a field critically lacking specialists.