I was just reading about Lexapro and anhedonia just now and it's honestly common among nearly all SSRI's I tried Prozac before that and felt the same way. That's what my doctor said. That's why he was reluctant to take me off it. A google search is riddled with connections of ssri's with anhedonia. Interestingly though, I found this random post suggesting that a hyperactive NMDA can cause problems when introduced to an SSRI. It was just a single post and that's all it said. I wonder why that person has that theory...