EXPLORING COMORBID OBSESSIVE-COMPULSIVE DISORDER AND ALCOHOL USE DISORDER USING NEUROPSYCHOLOGICAL TOOLS: A PRELIMINARY ANALYSIS

Abstract

abstract By investigating neuropsychological profiles in patients with obsessive-compulsive disorder (OCD) and OCD with alcohol use disorder (OCD+AUD), focusing on tasks of behavioural inhibition, attentional set-shifting and decision-making, we aimed to elucidate factors contributing to compulsive behaviour. Consenting patients (n=24) were recruited from outpatient clinics and attributed to DSM-IV OCD (n=14) or OCD+AUD (n=10) groups. Healthy controls with no relevant family history (n= 15) were identified through established databases and public advertisement. We used the Barratt Impulsiveness Scale (BIS) to assess behavioural impulsivity, the Stop-Signal Task for motor response inhibition, the Intradimensional-Extradimensional (ID-ED) Set-Shift Task for attentional flexibility and the Cambridge Gamble Task (CGT) for decision-making. Analysis of co-variance was used to test for group differences, controlling for depression (Montgomery-Asberg Depression Rating Scale) and anxiety (State-Trait Anxiety Inventory), for which both patient groups scored significantly higher (p When we co-varied for anxiety and depression, both patient groups showed poorer attentional flexibility on the ID-ED task than controls (p=.01, with large effect size). Motor response inhibition (SST) did not differ between groups, however the OCD+AUD group showed poorer attentional inhibition than both other groups on the attentional subscale of BIS (p=.001). The quality of CGT decision-making was also significantly poorer in the OCD+AUD group than in the pure OCD group and controls (p=.05). Interestingly, significantly higher (p Although our interpretations are limited by small sample size, it appears the impairment in decision-making, set-shifting and attentional impulsivity observed in OCD+AUD may be attributable to between-group differences in intelligence. There is some evidence that lower premorbid IQ may be linked with AUD, specifically in those patients with a strong family history of AUD. On the other hand, questions have been raised as to the validity of the NART as a specific measure of premorbid IQ in AUD. Future such studies should pay close attention to measuring to premorbid intelligence and its relationship with neurocognitive performance.