The telltale signs are ominous: teens holing up in their rooms, ignoring friends, family, even food and a shower, while grades plummet and belligerence soars.

• 躲在房间里，忽视朋友，家人，甚至食物，和洗澡，分数滑落，好斗性增加---这些“会给家长们告密的"都是不详征兆。