The effective dose varies with the person and 2.5 might work for you, only experience can tell. You also might take the lexapro in the morning if you are not already doing that. that may help you with the sleep pattern since lexapro seems to have a stimulant effect.
My advice to anyone about SSRI-antidepressants,
If you do not want to hurt yourself or others, are unable to work or enjoy your life or do simple things such as go out in public or take a shower, or are not diagnosed with clinical depression, DO NOT TAKE ANY SSRI. The FDA has been far too lenient with the pharmaceutical companies due to weak laws passed by politicians taking campaign contributions from special interest pharmaceuticals. This makes it easy for pharmacy representatives to push drugs (and easy for the family doc)that are being prescribed for other conditions for which they haven't been tested. Please make it your last resort behind all other methods of therapy, most importantly, lifestyle changes. These meds haven't been tested for long term use and have been linked to birth defects to unborn children, killing some, also sending many to the ER with crazy side effects. These are very serious medications that should never be prescribed by anyone other than a specialist,(although, I am leary of them also)
Don't take chances with these meds until you've done very much research and investigation. (I took 1 pill of Lexapro (10mg.) and have been unable to work for 3 months!!!!)I have also communicated with 7 others who have had a very similar situation to mine. Don't let the Doctors throw these dangerous medications at you or it may ruin your life. It seems that some or many people may be benefitting from these medications, and I don't claim to know everything abot them. Keep in mind, all the doctors, specialists and pharmacists that I have spoken to, claim to know VERY LITTLE about what these drugs actually do to the brain and nervous system. My point is, once you take these meds, you are on your own. If you have a horrible problem caused by these drugs, you will be alone, noone will want to help you, noone will be able to help you, you will be considered a liability and pushed aside as if your case holds no importance. I am speaking from my experience.I hope this helps at least one person make a better decision and subsequently saves many the grief that I have endured.
Thank you for reading all of this.