Investigation of the effect of combined cognitive bias modification on obsessive compulsive symptoms

Cognitive Bias Modification (CBM) is a cognitive intervention that experimentally modifies cognitive biases by using a series of disorder-related stimuli designed to manipulate cognitive process relevant to psychopathology. CBM is also a promising treatment for Obsessive Compulsive Disorder (OCD). However, previous studies have not systematically examined the combination of CBM for attention and interpretation, or the credibility and acceptability of this type of protocol. In the light of the fact that attentional and interpretation biases both play important roles in the development and maintenance of obsessions and compulsions, the combined protocol of CBM intervention is assumed to produce enhanced positive effects on OCD symptoms. In this regard, the aim of the study is to examine the effectiveness of the Internet-Delivered Combined Cognitive Bias Modification (iCBM-C) on OCD symptoms, obsessive beliefs, attentional and interpretation biases, anxiety, depression, stress and mood in non-clinical sample of individuals high in OCD symptoms. The sample of this study consists of 82 participants (65 females, 17 males) between the ages of 18-40 (M= 26.5, SD = 5.93) who reported high levels of OCD symptoms. Participants were randomly assigned to the iCBM-C (the combined iCBM-I and iCBM-A interventions), iCBM-I (CBM intervention for interpretation only), iCBM-A (CBM intervention for attention only), and wait-list control (WLC). Among instruments for data collection, Personal Information Form, DSM-5 Self-Rated Level 1 Cross-Cutting Symptom Scale-Adult Version, Padua Inventory–Washington State University Revision, Obsessive Beliefs Questionnaire-44, Depression Anxiety Stress Scale-21, and Positive and Negative Affect Schedule were used. In addition, behavioral assessments were also taken using experimental tasks such as the dot-probe task to evaluate attentional bias and the recognition scenarios task to evaluate interpretation bias. Instrument tools were administered to the participants before, after the intervention and one month later; whereas, behavioral assessments were taken before and after the intervention only. The data obtained were analyzed by 4x3 mixed ANOVA. The data obtained from behavioral measurements were analyzed by 4x2 mixed ANOVA. In the results of the study, it was found that iCBM-C was effective in reducing OCD symptoms, obsessive beliefs and interpretation bias. The change obtained in OCD symptoms and obsessive beliefs were also preserved in follow-up measurements. However, the expected effect of iCBM-C was not seen in terms of reducing attentional bias, depression and negative emotions and increasing positive emotions; in terms of anxiety and stress, this effect was observed only in follow-up assessments. In general, iCBM-C was found to be more effective than iCBM-A in reducing obsessive beliefs and interpretation biases. Moreover, iCBM-C group differed significantly from WLC in reducing interpretation bias. In addition, the result of the Modified Intention to Treat analysis revealed similar findings. Findings and limitations of the study were dicussed in light of relevant literature and future directions for research and clinical practice were recommended.