If someone you know is suffering from PPD, please don't say insensitive things like "well, you're the one who wanted children so bad," or "just get a grip, s/he is just a baby," both of which I've heard in recent weeks. Be careful that the things you say to moms with PPD don't make them feel like they are to blame for their depression or the symptoms of their depression. Mama Christa and I can both tell you that those moms are feeling crappy enough about the thoughts and feelings they are having, about their worth as mothers, wives, and friends. Offer to help if you can, even if all you are doing is keeping the mom company. Support her in getting help if she needs it, refer her to Jenny's Light for information and resources, and be a safe person she can share with without judgement. Mama Christa's post about Postpartum Depression is evidence that so many mothers are suffering, and they don't feel safe sharing such intimate details of their pain, anger, and depression, so be available as best you can to moms in this position. Just like every baby and every mom is different, every PPD experience is different. It's not what I thought it was from reading and education, but it sure sucks.
For many mothers with PPD medication is a safe and effective route to treatment. Kelly Mom lists Dr. Hale's research on anti-depressants in breastfeeding mothers, and here is that information for you and for you to share with those who may benefit. Not all doctors are familiar with medications safe during pregnancy, so educate yourself about it!