Treatment without target? No meta-analytical evidence for baseline bias towards threat in 860 clinically anxious individuals enrolled in Attention Bias Modification RCTs

Background: Considerable effort and funding are spent on developing and assessing clinical efficacy of dot probe task (DPT) based Attention Bias Modification (ABM). ABM is regarded as a potential new (online) treatment for anxiety disorders especially. Anxiety disorders are commonly asserted to be characterised by ABM’s treatment target: preferential processing of threatening information. Yet the available meta-analytical evidence for this specific threat-bias in clinically anxious individuals is thin: the largest meta-analysis to date included DPT data for only n= 337 clinically anxious individuals. We reasoned that the baseline bias measures obtained in RCTs for ABM constitute a considerable, hitherto not assessed, body of data on the existence of DPT threat bias in clinically anxious samples.Method: Baseline ‘threat vs neutral’DPT summary data for n= 860 clinically anxious individuals enrolled in k= 11 ABM RCTs were meta-analysed using REML. Additional Bayesian analysis was used to assess support for a series of 1 ms wide bias size intervals.Results: REML analysis indicated no evidence that mean observed Bias Index (BI) differs from point zero (k= 11, n= 860, mean BI= 1.8, SE= 1.53, p=. 229, 95% CI [-1.2-4.8]). Bayesian analyses indicated moderate support for the traditional ‘point-zero’over the ‘not point-zero’hypothesis (BF01= 6.7). Interval-based Bayesian analysis suggest that BI most likely falls in the 0-1 ms interval (BFinterval/notinterval= 231) and is almost certainly not larger than+ 2 ms (towards threat), or-1 ms (away from threat).Conclusion: Clinically anxious individuals enrolled in RCTs for Attention Bias Modification do not …