None of that should make you question your faith.
The Bible speaks of those who will come and try to twist the Word.
god makes some people big bucks, it gives others immense power. Why not push it further into other areas?
But,
Not all mental illness is chemical imbalances. If you've ever seen the true face of evil in a person, you, regardless of your beliefs, have to agree that literally the debbil is straight up working in some people. Some embrace it, others are tortured and fight it until their last breath.
God made this world. Medication is in this world. There is no good argument for not using medication that is indicated for a disease, except this: don't allow medications to be your God. The answer becomes another pill and not getting on your knees and seeking God first. Maybe He intervenes in a supernatural way, maybe he made prozac just for what's going on.
As we get further and further from His will, cancers and other unplanned changes to our bodies will become more frequent. As God appeased us even in the Old Testament, He continues to appease us and our lack of faith with pharmaceuticals, I believe. Do not put the Lord thy God to a test; if he's provided the answers in a hospital setting, only a fool would deny the power of healing. But never stop praying, and be thankful always for His responses.