If some has clinical depression or any other kind of mental illness it is a reasonable option to take medication. It does not mean the person is weak. Taking medication is admitting that you have a problem. Often admitting a problem is the first step to solving it. Anti depressants are a valid option and should carry no stigma.
Using medication does not rule out other methods. Infact the use of medication can make things like CBT more effective.
I know someone with depression who is very proud that she not taking medication. I think she is misguided. Both her and baby are suffering unnecessarily.