AFirst of all, I want to reassure you that the way you feel is completely appropriate. Your daughter is going through a time of life when everything is changing -- the shape of her body, her relationship with other kids, her sexuality, her identity. It's not an easy time for children -- or for parents. Some insight into what is going on internally for teenagers may help you understand and cope.

At 15, the work a teenager has to do is that of separating from her parents and becoming an individual. She needs to learn how to become her own person. The only way she knows to do that is by trying out different behaviors and seeing how the people around her respond. Some of those behaviors are the kinds that the environment reinforces and others are the kinds that the environment punishes or puts down. In any case she's learning which behaviors work and which don't.

Your daughter needs to find a healthy way to develop and to emerge from this process. In her eyes, this involves rejecting the close relationship with her parents, a relationship which can be interpreted by teens as being dependent and childish. She needs not only to carve her own way, but also to engage in behaviors that are going to cause that separation to take place.

What are those behaviors in her eyes? One such behavior means saying to Mom, "A clean room means a lot to you. I don't want to be so closely identified with you so I'm not going to clean my room. I don't want to fit into that perfect little girl mold, I want to be my own individual." That doesn't mean that when she's 18, she's not going to want a clean room. It means that right now her primary task is to develop her own identity separate from what her parents want her to be -- not someone with a clean room.

THIS TOO SHALL PASS

It might help to know that the kinds of things you describe -- messy rooms, mood swings -- are typical of the teen years. You sound like a very capable woman, blessed with strengths and insight. But none of these tools are helping you right now. You might be interpreting your daughter's behavior as meaning that you are not capable of raising her the way you want. No wonder you're feeling depressed! But hang in there, because this too shall pass.

Having said all that, there is no getting around the fact that it is very painful for a mother when a child suddenly ignores her -- especially if the relationship was close before. Mothers need emotional feedback as much as children do. When that's withdrawn, it helps to turn to other sources, such as friends who are also mothers of teens. And don't forget the importance of a sense of humor. Your letter indicates you have a healthy sense of humor as well as perspective; both are important resources for you.

Now for some specific suggestions for how to deal with the issues you present:

- Remember that your daughter is in essence the same person she was before her 13th birthday, so choose your methods based on previous ways of relating to her. If logic used to work, keep using logic. If a more touchy-feely approach worked before, then go with that --even if you don't see immediate results. (I used guilt quite successfully in my own family when one teenager began picking on her younger sibling, by emphasizing how much an older child's words can affect her younger sister.)

- It's very important to be consistent. Teenagers are testing themselves against their environment and if the environment is constantly changing, they don't have the framework they need to figure out what the limits are. While there are no consistent rules that will work all the time with all teenagers, your child needs to know that you're always there for her in a strong and stable way, balancing her inner feeling of instability.

- Choose your battles. If her maintaining a spotless room is vital to you but you feel it's okay if she ignores you once in a while, that will be the battle you choose. But if giving her sister a break is less negotiable for you than keeping her room clean, try keeping the door to her room closed.

- Involve your daughter in decisions that affect her. Say something like, "It really upsets me when you scream at me for no apparent reason -- it really hurts. Let's figure out a way that you can express yourself without screaming at me." Or together, reach some kind of compromise about her room -- for example that by Friday, her room should be decent for the weekend.

Going through a difficult stage with a child doesn't mean you're a failure as a mother. It takes time to learn a new way of relating. She'll probably outgrow her teenage years at about the time that you finish figuring out how to deal with them! But remember, you survived the other two and you will survive this one -- and the next one as well!