Will the jitters come back whenever you increase your Lexapro dosage and for how long?

YOU SHOULD NEVER increase or decrease ANY medication (especially the one you are on) without your doctors permission and supervision. If the doctor told you to up the dose slowly then there is no reason you should get the jitters because your system is already use to this medication. In fact, you could have the jitters because the dose may not be high enough for you. Up this dose ONLY with your doctor's permission!