After several years of taking Lexapro 20 mg, it's effectiveness seemed to be wearing off over the last few months and I became highly irritable, impatient and yelled a lot. My doctor suggested adding 150 mg of Wellbutrin and it has helped tremendously. I don't feel the best I can be, but I do feel a lot more calm and stable. I have not seen any affects such as appetite reduction or increase in libido. It's been a month on this dosage. How do I know if I should increase to the standard therapeutic dosage of 300 mg? And if I do, should I take both pills (150 mg each) at the same time or space them out? Thanks a lot!