If it is a psychological evaluation - you can't fake it, so don't try. Just be honest.
*You might hear all sorts of nonsense out there about how to fake having a mental illness or fake not having one... The truth is, it is easy to fake out an expert for a short time, but it is nearly impossible to keep up the ruse. And, the instruments used for evaluation have built in detectors for faking. So - unless you are an expert in psych yourself, I wouldn't even attempt it. *