B - 51 The Relationship between Delusional Thinking and Processing Speed in Community Adults.

Abstract

Adults diagnosed with a psychotic disorder demonstrate heterogeneous neurocognitive performances, though the relationship between delusions and neurocognition among nonclinical adults remains largely unstudied. This study addressed this gap by examining how nonclinical delusional thinking impacts processing speed and speeded inhibition. Participants included an adult community sample who completed a neuropsychological battery through the Nathan Kline Institute's Rockland Project. The 1111 participants were 36% male, ages 18-85 (M = 47, SD = 17.97), and 76% White, 16% Black, and 5% Asian. Delusional thinking was assessed using the total score on the 21-item Peters et al. Delusions Inventory. Processing speed and speeded inhibition were assessed using age-adjusted scores from the Delis-Kaplan Executive Function System (D-KEFS) Trail Making Test (TMT) and Color-Word Inhibition Test (C-WIT). Linear regression analyses were conducted to assess whether delusional thinking predicted performance on TMT and C-WIT tests. Greater delusional thinking predicted poorer performance on TMT tests of Number Sequencing (R2 = 0.005, p = 0.023), Number-Letter Sequencing (R2 = 0.005, p = 0.018), and Motor Speed (R2 = 0.005, p = 0.021). For performance on Letter Sequencing and all C-WIT tests, there were no statistically significant relationships with delusional thinking. Results indicated that faster psychomotor processing speed, not visual processing speed, was significantly associated with lower delusional thinking in a community sample. Therefore, it may be particularly useful to include measures of psychomotor processing speed when assessing individuals with delusional symptoms. A replication study with greater variability in delusional thinking may elucidate the relationship between delusional thinking and cognitive functioning in nonclinical populations.