Has the neuro adjusted your med Lexapro more than once during those months? I sure hope so! Why not try another med, if it's as high as he can take it.

Unfortunately, depression is common with any chronic illness

It really depends upon your system as to how soon you will notice a change. . . but the medicine begins working as soon as it enters your system. HOW depressed you are (and how much chemical adjustment the med needs to make) determines how long it needs to build up to a therapeutic level. Keep trying!