B vitamins are also essential co-factors for producing the neuro-transmitters the Lexapro is acting on, so they should aid its functioning without increasing its functioning. Same with
omega-
3 oils, as anti-depressants often cause weight gain and increased cholesterol, which is aided by omega 3 oils, and they also aid brain function, particularly fish oil (DHA). Fish oil is also said to help with the brain zaps some people get when they stop ssris, so it's useful to have in your system.