I was on 10 mg of Lexapro for nine weeks Dr changed it from 10 to 15 I am on the 15 four 2 1/2 weeks I have not felt any improvement yet how long does it usually take when you have an increase do you have to start all over again to feel the full effects I have very bad anxiety I am a 70 year old female my weight is 119 pounds height is 5Feet 4 inches