Dear Mr. Dad: I am a single mom of a 14-year-old daughter. Throughout much of her childhood I suffered from severe depression, which went undiagnosed until very recently. I’m getting treatment now, and I’m feeling much better. However, my daughter thinks I was pretending to be sick all those years. That really hurts, but how do I explain to her what was really going on?

A: What a difficult situation for both of you. I get a sense from your letter that she either doesn’t know that you were depressed, or simply doesn’t understand what depression is. Or both. As a result, she believes (mistakenly, of course) that depression isn’t a “real” illness and that it’s “all in your mind,” or something you should be able to just snap out of.

The very first thing to do is sit down with your daughter and explain to her that depression isn’t some kind of character flaw. It’s a real sickness, with real symptoms, and there’s absolutely nothing shameful about it – just as there’s nothing shameful about diabetes or cancer or heart disease. And like most medical conditions, it’s not caused by anything specific that you did or didn’t do.

If you need a little guidance for this conversation, the National Institute of Mental Health has an excellent pamphlet that you can download from its website. The URL’s a bit long, but it’s well worth the trouble. At the very least, this will show your daughter that you’re not just making things up or lying to her, and that a legitimate, reputable organization recognizes the reality of depression too.

Once you lay out all the facts, tell your daughter that you understand why she might feel that you essentially abandoned her for all those years. Also share with her what you told me–that it hurts you to know you weren’t always able to be the kind of parent she deserved to have.

Let her know that since your condition was undiagnosed for a long time, you didn’t fully understand what was happening, and you couldn’t get the help you needed. Tell her about the symptoms you may have experienced, such as chronic fatigue, heart palpitations, panic attacks, inability to make decisions, feelings of hopelessness, constant sadness, and complete lack of motivation. You obviously don’t want to frighten your daughter, but she’s old enough to know that you truly were incapacitated and unable to function as a healthy mom–although you never stopped loving her, and wish you would have been better able to show her.

Tell her that you’re being successfully treated now with medication, therapy, or both, and would like to rebuild your relationship. Unfortunately, there’s no way to make up for lost, time but your teen daughter needs you in her life just as much now as she ever did. This is one of those situations where the old saw, “better late than never” is actually true.

This doesn’t mean life will be all rosy from here on out. Chances are it won’t. Your daughter may (justifiably) be resentful, suspicious, distrustful and angry, and might even rebel against having you back in her life after all these years. And she may throw your depression back in your face (expect comments like, “you must be off your meds”). So tread lightly and be patient. In her eyes, you’ll have to earn her trust. Consider some family counseling to smooth out the transition for both of you.

Whatever happens, make sure that she knows you love her and that you’re in this for the long haul.