A-155 Depression’s Effect on the Processing Speed Index of the WAIS-IV in a Sample of Individuals with Attention Deficit Hyperactivity Disorder (ADHD)

Abstract

Objective: The neurocognitive profile for individuals with ADHD reveals impaired processing speed scores (Kramer et al., 2020; Onandia-Hinchado, et al., 2021). Depression has been associated with impairment across cognitive domains, including processing speed, even after remission of depressive episodes (Ahern & Semkovska, 2017; Semkovska, et al., 2019). In addition, the co-occurrence of ADHD and Depression may result in impaired processing speed beyond the deficits typical for those with only one of these disorders (Larochette, et al., 2011). This study will further investigate the cumulative effects of comorbid ADHD and Depression by exploring if those with comorbid depression perform more poorly on processing speed measures than individuals with ADHD and no comorbid depression when controlling for intellectual ability. Method: This study used archival data from a private practice neuropsychology clinic in the Midwest. This study included 233 adult participants diagnosed with ADHD, including 92 with a diagnosed comorbid depressive disorder. Processing Speed was examined using the Processing Speed Index (PSI) from the Wechsler Adult Intelligence Scale- Fourth Edition (WAIS-IV). Participant intellectual functioning was controlled for using the VCI of the WAIS-IV. Results: An ANCOVA was used to examine the differences in PSI. The covariate VCI accounted for 19.9% of the variability in processing speed (ηp2 = .199; p = .000). Comorbid depression was non-significant and accounted for 0.1% of variability after controlling for VCI (ηp2 = 0.001; p = .640). Conclusion: There is a minimal relationship between co-morbid ADHD and depression and processing speed. Impaired processing speed in clients is likely attributable to effects of ADHD.