title: Olfactory identification deficits and associated response inhibition in obsessive-compulsive disorder: on the scent of the orbitofronto-striatal model.
abstract: Olfactory identification ability implicates the integrity of the orbitofrontal cortex (OFC). The fronto-striatal circuits including the OFC have been involved in the neuropathology of Obsessive Compulsive Disorder (OCD). However, only a few studies have examined olfactory function in patients with OCD. The Brief Smell Identification Test (B-SIT) and tests from the Cambridge Neuropsychological Automated Battery (CANTAB) were administered to 25 patients with OCD and to 21 healthy matched controls. OCD patients showed a significant impairment in olfactory identification ability as well as widely distributed cognitive deficits in visual memory, executive functions, attention, and response inhibition. The degree of behavioural impairment on motor impulsivity (prolonged response inhibition Stop-Signal Reaction Time) strongly correlated with the B-SIT score. Our study is the first to indicate a shared OFC pathological neural substrate underlying olfactory identification impairment, impulsivity, and OCD. Deficits in visual memory, executive functions and attention further indicate that regions outside of the orbitofronto-striatal loop may be involved in this disorder. Such results may help delineate the clinical complexity of OCD and support more targeted investigations and interventions. In this regard, research on the potential diagnostic utility of olfactory identification deficits in the assessment of OCD would certainly be useful.
authors.affiliation: DSM ASL/LT, Unit of Psychiatry, Department of Medical-Surgical Sciences and Biotechnologies, A. Fiorini Hospital, Terracina, Faculty of Pharmacy and Medicine, Sapienza University of Rome, Italy. Electronic address: giuseppe.bersani@uniroma1.it.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Bersani
authors.forename: Adele
authors.initials: A
authors.lastname: Quartini
authors.forename: Flavia
authors.initials: F
authors.lastname: Ratti
authors.forename: Giulio
authors.initials: G
authors.lastname: Pagliuca
authors.forename: Andrea
authors.initials: A
authors.lastname: Gallo
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001288:Attention / Q000502:physiology; D003072:Cognition Disorders / Q000209:etiology; D003342:Corpus Striatum / Q000473:pathology*; D056344:Executive Function; D005260:Female; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D009771:Obsessive-Compulsive Disorder / Q000150:complications / Q000473:pathology / Q000523:psychology; D000857:Olfaction Disorders / Q000175:diagnosis / Q000209:etiology*; D017397:Prefrontal Cortex / Q000473:pathology*; D055815:Young Adult
keywords: B-SIT; CANTAB; Impulsivity; OCD; OFC; Olfaction; Response inhibition