A transdiagnostic comparison of paranoia and cognitive-affective risk factors in Williams syndrome and schizophrenia spectrum disorders

Williams Syndrome (WS) is a rare neurodevelopmental disorder marked by elevated social motivation and approach. Individuals with WS exhibit a distinctive cognitive-affective profile, including heightened anxiety, rigid thinking, and susceptibility to cognitive biases – all risk factors for disturbances of thought content such as paranoia. However, despite these risk factors, psychotic disorders are relatively uncommon in WS, raising the possibility that its social phenotype may mitigate clinically significant paranoia. We compared self-reported paranoia and associated cognitive-affective risk factors across individuals with WS ( n = 19), schizophrenia spectrum disorders (SSD; n = 66), and healthy controls (HC, n = 70). Although both clinical groups exhibited elevated cognitive-affective risk factors relative to HC, individuals with WS reported less persecutory paranoia, more robust social networks, and less social avoidance than those with SSD, despite comparable social anxiety. In SSD, less robust social networks were associated with a stronger relationship between social-cognitive difficulties and persecutory paranoia than in WS. The Bias Against Disconfirmatory Evidence task revealed impaired belief updating in SSD, but relatively preserved belief updating in WS. These findings are consistent with the hypothesis that social factors and belief updating may attenuate paranoia despite elevated risk factors, providing transdiagnostic insight into the social and cognitive processes shaping vulnerability to paranoia.