When I worked forensic psych pretty much everybody who wanted to plead insanity was trying to weasel out of something horrible (time spent institutionalized NGRI is almost always waaay longer than an equivalent prison sentence so it’s only worth it if you’re going away for life anyway).

The people who were legit psychotic would just keep defending the psychosis as reality in increasingly bizarre ways. They’d demand to represent themselves because the court appointed lawyer kept trying to talk them into accepting treatment but noooo, they needed to make a public statement about the gay bar being full of alien pedos.