青少年故意自伤行为不仅造成身体组织上的损伤，还影响心理和社会适应性的发展，是一项亟需关注的公共卫生问题。本研究拟采用现况研究和1:1匹配病例对照研究相结合的流行病学方法探索慢性应激和TPH基因的交互作用对青少年故意自伤行为的预测作用，具体包括：通过现况研究分析自伤行为的现状、流行特征和筛查病例；通过病例对照研究明确慢性应激（主要包括焦虑、抑郁、恐惧三种情绪状态）与自伤行为的关联性，明确TPH基因（包括TPH-1和TPH-2）多态性分布与故意自伤行为的关联性；通过统计学方法明确慢性应激与TPH基因的交互作用及构建自伤行为的风险预测模型。研究结果将阐明应激、基因、及其交互作用对青少年故意自伤行为的影响，为特异性干预措施的制定及预测预警系统的建立提供科学依据；同时，本研究将分子生物技术运用到青少年危险行为的研究中，为今后相关研究的开展提供了新的研究思路。

Deliberate self-injury behavior (DSB) among adolescents is a public health problem which need focused on urgently, because it not only cause damage to body tissues directly, but also affect the development of psychology and social adaptability. A cross-sectional study combine with a 1:1 case-control study will be employed in the present research to explore the predictive effects of the interaction of chronic stress and TPH gene to adolescent's DSB. The cross-sectional study will be conducted to describe the status, epidemic feature of DSB and to screen the cases of DSB among adolescents. The case-control study will be used for exploring the assocation between chronic stress (mainly include anxiety, depression and panic status) and DSB; the assocation between the single nucleotide polymorphisms (SNPs) of TPH gene (include TPH-1 and TPH-2 gene) and DSB. Statistical methods will be used for examining the interaction between chronic stress and TPH gene,and for establishing the risk prediction model of DSB. The results of the present research will explain the influencing factors of DSB among adolescents from the views of stress, gene, and its' interaction, which will provide evidences for making specific interventions and establishing predictive system that is good for healthy growth of adolescent; meanwhile, the molecular biological technology will be applied in the present research, which will provide a new thought of research method for studying youth risk behaviors in the future.