Epidemiological evidence shows a substantial increase in adolescent emotional problems in many countries, but reasons for this increase remain poorly understood. We tested change in emotional problems in a national sample of young people in Wales in 2013, 2017 and 2019 using identical symptom screens, and examined whether trends were accounted for by changes in youth friendship quality and bullying.

中文翻译：

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2013年至2019年威尔士青少年情绪问题的趋势：同伴关系的贡献

流行病学证据显示，许多国家青少年情绪问题大幅增加，但人们对这种增加的原因仍知之甚少。我们使用相同的症状筛查测试了 2013 年、2017 年和 2019 年威尔士全国年轻人样本中情绪问题的变化，并检验了趋势是否是由青少年友谊质量和欺凌行为的变化引起的。