Hi J.,
I personally have never taken Zoloft but I know someone who has. Granted she is older, not postpartum. She began taking it I believe when it first came out (due to depression and somewhat suicidal tendencies). She is still on Zoloft and still manic. The Zoloft has seemed to calm her to an extent on some days, though it has never cured her of anything and has left her dependent on the drug for life.
My personal opinion is that Zoloft doesn't solve any problems or conditions, it just makes the same problem 'different.' When we consider that drugs do NOT heal and that they simply mask and/or change the initial problem for some be enough to get them to explore alternative options. This is not to say one should or shouldn't take drugs, it's just my opinion, what I've seen and know. For instance, antidepressants can compromise your immune system (leading to all kinds of other problems down the road), which is only one of many potential harmful side effects.
My personal preference is to always look for an alternative option over drugs for the past 35 years - taking drugs/meds has always been a last resort for me, I have always found other ways that were effective and helped me with my problems. If you happen to lean towards more natural solutions you may want to explore something else.
I am very big into therapeutic essential oils and as such I do sell them - I believe in them entirely. This is not to say you should use them and I'm certainly not trying to sell you on them. I'm just thinking you may want to explore them and other options.
Here's an article on my blog showing some of the ways I use my oils daily http://aromatherapy4u.wordpress.com/2008/12/10/60-easy-wa...
I also write a weekly E-Newsletter on using therapeutic essential oils, last week was on 'Happiness,' i.e., mood. You may want to check it out and see if it resonates with you. My newsletter archive is here http://community.icontact.com/p/theveryessence/newsletter...
Since the age of 15, I began exploring plants, herbs, essential oils, and healing foods - I am soooo glad I discovered, and met helpful teachers and people along my journey... they and the healing plants have certainly enhanced my life and well-being.
I love helping others learn about and how to use essential oils so if you have any questions please let me know - it's a whole world that most know little about... humankind's first medicines.
My best wishes to you on which ever path you take,
E.
P.S. - I almost forgot... for those who are really interested in 'natural' solutions there have been some studies done on depression and soil organisms - yes, it turns out that there are some soil organisms that work better than antidepressants.
Taking up gardening can produce great benefits for your health naturally than to rely on drugs that provide no meaningful upside whatsoever, and certainly in no way, shape or form treat the underlying cause.
Here are links if you're interested in learning more...
http://www.medicalnewstoday.com/articles/66840.php
http://www.sciencedirect.com/science?_ob=ArticleURL&_...