Clarifying the Influence of Comorbid Depression on Response Inhibition in Obsessive-Compulsive Disorder and Trichotillomania

Abstract

Response inhibition performance in Obsessive-Compulsive and Related Disorders (OCRDs) is emerging as a potential neurocognitive endophenotype of these disorders. A point of needed clarification, however, is how unique such performance is to the OCRD spectrum. Specifically, it is unknown whether comorbid depression, a disorder that frequently occurs with OCRDs (60-80%) (Pallanti et al., 2011) and is also associated with cognitive deficits, can influence response inhibition observed in OCRDs. We sought to clarify whether response inhibition performance could be reliably accounted for OCRD symptomology (in obsessive compulsive disorder and trichotillomania specifically) even when taking into consideration the influence of comorbid depression. Additionally, we investigate the interplay between RI and associated OCRD factors in domains of impulsivity, incompleteness and life disability. We found that response inhibition performance is not accounted for OCRD symptomology in aggregate (i.e., OCD and trichotillomania), but is uniquely related to compulsion severity in the context of OCD. Additionally, response inhibition performance is largely unrelated to associated domains of impulsivity, incompleteness and overall life disability.