Depression is also very strong in my family -- mother, grandmother, aunts, cousins, second cousins -- you name it. Sadly, aside from my mother, I never knew any of the others dealt with it until I was hospitalized with clinical depression a year ago. Funny how that happens.
I think I may be able to shed a little light on your friends situation with what I have learned the past two years on my journey. First, I was worried about how getting pregnant this time would affect me since I wanted to go off my meds during the pregnancy if possible. He told me that for some people pregnancy seems to have a very protective effect and they don't have problems while pregnant (and possibly while breastfeeding.) The guess is that for some people the hormones seem to take over and keep us on an even keel. Keep in mind that this doesn't happen for everyone, but it seems to be the case for me, and likely your friend also.
For as long as I can remember my mother has lived with clinical depression. She was hospitalized several times when I was a young child. She was on tranquilizers during brief periods when I was a child, but I don't remember it. She said that she would always go off because she didn't like the side effects. She and my dad basically lived as roommates and didn't have much of a marriage. My mom was always sort of sad and "depressed" is what most people think of as depressed -- blue, down, etc. You would think that growing up around this I would have a clue about depression. Turns out that I didn't. At age 32 I wasn't able to see it in myself because it wasn't what I thought it was going to be.
I always thought that my mom was sort of "weak." I didn't think that she should just snap out of it, but in the back of my head I thought that she wasn't strong enough as a person to stand up for herself to my dad, to take control of her life. I was so wrong.
I was 32 when my problems started. I began to have anxiety about a lump in my breast. That was resolved and I was told there was nothing wrong, but I couldn't shake the fear that they were wrong (my mom had breast cancer at age 30.) That lump eventually went away, but the beginning of that summer I began to have periods where my heart would race, skip beats, I would feel hot. I was terrified. I knew there was something very wrong with my heart. Many EKG's visits to my internist later I was told that I was fine. My internist told me I was a hypochondriac and that there was nothing wrong with me.
Then in August, a couple months later, I really started to go down hill. All the symptoms were continuing but adding more. I found myself totally fatigued all the time. I was constantly nauseated and couldn't eat. I worried constantly that there was something seriously wrong with me but the doctors were overlooking it. In August of 2002 I weighed 115 pounds. One month later I was below 100 pounds. I couldn't care for my kids, I couldn't get out of bed at times, I would still have attacks with my heart beating fast and all those symptoms. One night after a trip to the er because of the symptoms the doctor told me I was having panic attacks and sat down and showed me all the symptoms and explained it to me. He also told me to go to my doctor the next day, that he would call her and she could start me on something. Saw her the next day, she put me on Paxil and Xanax, but then proceded to ignore my calls for a week and a half that I was getting much worse. At that point my dh took me to the er again because I was at the lowest he had ever seen me and was really scared. I couldn't even function and I didn't know why. Once again those wonderful er doctors took over and I was diagnosed with Clinical Depression with Anxiety and admitted to the hospital to start on meds to ensure they worked and to begin eating again and gaining weight.
My guess is that your friend doesn't necessarily have all the anxiety symptoms I had, that is just how my illness begins to manifest itself. The reason I told you that whole novel is to show you that someone who has grown up around depression can be so ignorant about what it really is and does when it comes to them. I had no idea what it meant that depression was a chemical imbalance. I thought that those people had flaws in there personality that made them somehow weak and suseptible. I was always the strong one in my family -- there was NO WAY I could possibly suffer from depression. I was way too strong. Looking back I can see that my depression began around the time my ds2 was a year old -- a year before I was hospitalized. I just failed to see the symptoms because they sort of crept in slowly at first. It was so slow that they felt somewhat normal. My trigger was severe sleep deprivation. I hadn't gotten more than four hours of sleep a night (and not in a row) in two years. You just can't live like that.
Your friends depression is indeed a chemical/physical illness, but if she is like me, she can't see it because she is the "normal" one. I was exactly the same way. Depression is an imbalance of the neurotransmitters in the brain. The chemistry is off and the brain isn't able to function the way it should. The result is depression in general and a myriad of other physical symptoms that can follow -- anxiety, rage, social phobia, nausea, heart palpitations, etc, etc, etc -- if the disease is left untreated.
I would encourage you to contact a local counseling center or psychiatric office. They will have literature you can take and read. Check the web for information. Sometimes seeing the sympotms and the explanation of what depression really is can help. Be warned that much of the information will come from drug companies though and will be biased toward their medication. Talk to her about your concerns and if she would like to talk to someone who has been there, I would be happy to "talk" to her. It sounds like we have a lot of the same attitudes and history. I would be happy to PM you my email address. Show her this post and this forum. Life is too short to feel like she does.
Good luck, I've got to sign off and pick ds1 up from school.