Traditional models of psychosis link symptoms like persecutory ideation to impairments in brain systems that balance deliberation with affect drives like threat detection. My laboratory has investigated these links using the Minnesota Trust Game in fMRI which allows us to distinguish rational mistrust from more pathological processes like paranoia that manifest as spite sensitivity. While this empirical work points to specific failures in deliberation allowing for overactive threat detection, it also points toward a broader framework: trust as an optimized signal detection task. I will link our empirical work to potential neural distortions that shift trust optima, creating a number of specific paths to distrust and conspiracism. Ultimately, I argue that widespread shifts in trust criteria constitute a public health risk factor with profound consequences for societal well-being.