ANTICIPATED REWARD IN OBSESSIVE-COMPULSIVE DISORDER

Abstract

abstract Introduction The affective state that occurs during the anticipation of a behavior is typically associated with the expected outcomes of that behavior [1] . This notion is relevant for compulsive behaviors in obsessive compulsive disorder (OCD), which is characterized by a deficit in using accurate models of prospective action-outcome scenarios [2] . This deficit may in turn influence anticipatory affect and exacerbate compulsions despite their detrimental consequences. In this study, we directly investigated self-reported affect prior to, in anticipation of, and after OCD-related compulsions to elucidate the role of positive and negative affective states in compulsive behavior. Methods Twenty-two consecutive and treatment-seeking OCD patients (mean age: 39.17± 12.42 years, 11 males) completed the Temporal Impulsive Compulsive Scale, a self-report instrument that was developed to assess affective states over time during specific repetitive behaviors. Participants indicated how intensely they experienced a selection of Positive (n=6; cheerful, proud, determined, confidant, energetic, alert) and Negative (n=8; guilty, lonely, nervous, sad, afraid, disgust, ashamed, irritable) Affective Scale (PANAS) [3] items before (pre-choice phase), in anticipation of (anticipatory phase), and after (consumatory phase) their primary OCD symptom (i.e., washing, checking, ordering or hoarding). Scores were calculated (in centimeters) based on a visual analogue scale that varied from 0 “not at all” to 10 “extremely”. Mean responses were separately calculated for Positive (PA) and Negative Affect (NA) at each temporal phase. Each participant received one mean score for items within the PA scale and one for items within the NA scale. We defined increase or decrease in positive or negative affect when patients showed a difference of more than one standard deviation shift from the pre-choice phase to anticipatory phase. Results Twenty of the twenty-two OCD patients showed an increase in positive affect from pre-choice to anticipatory phase, while two patients showed no change in affect. Of the twenty patients, ten additionally reported a decrease in negative affect. These ten patients included three washers, three checkers, three hoarders and one patient with symmetry symptoms. The remaining ten patients showed either a concomitant increase (n=6) or no change (n=4) in negative affect during the shift from pre-choice to the anticipatory phase. These patients included three washers, three checkers, two hoarders and two patients with symmetry symptoms. Conclusions It is intriguing that almost all of the OCD patients studied showed an increase in positive affect in anticipation of their compulsion; and ten of them showed a concurrent decrease in negative affect while the remainder showed either a concurrent increase or no change in negative affect. The increase in positive anticipatory affect may indicate a rewarding aspect of compulsions, which could contribute to their persistence. These findings may be particularly relevant to those OCD patients who show blunted nucleus accumbens activity during anticipation of generic rewards, which are be offset by enhanced activity of the same during anticipation of performing OCD-related compulsions. This supports analogies between OCD and addiction [3] and is consistent with the co-occurrence of compulsive and impulsive symptoms in OCD and addictive disorders.