An Examination of Intolerance of Uncertainty in Schizophrenia

Schizophrenia is associated with multiple comorbidities and symptoms, suggestive of common transdiagnostic processes. Elevated intolerance of uncertainty (IOU) is one such transdiagnostic process, but little research has been conducted in schizophrenia. This study assessed the associations between IOU, schizophrenia diagnosis, and schizophrenia symptoms using a between-groups cross-sectional design. The sample comprised 113 participants, 72 people with a schizophrenia diagnosis and 41 control participants without (73 male, 40 female, age range 19-69 (M = 42.1, SD = 13.0). Measures of schizophrenia symptoms, intolerance of uncertainty, depression and anxiety symptoms, rumination, executive functioning, and rumination were taken. Schizophrenia diagnosis was predicted by lower prospective IOU and higher levels of inhibitory IOU. Specifically, the prospective IOU subscale was uniquely associated with general schizophrenia symptoms. Higher levels of positive symptoms were associated with lower inhibitory IOU and higher prospective IOU, however, not when anxiety and depressive symptoms, rumination, and verbal fluency were controlled for. No unique associations were found with negative symptoms. Rumination did not mediate prospective IOU and general schizophrenia symptoms. Different directions of association between the subtypes of IOU and schizophrenia diagnosis, as well as distinct relationships between IOU and symptom subtypes suggest that prospective and inhibitory IOU have distinct associations with the disorder.