What’s in a Trial? On the Importance of Distinguishing Between Experimental Lab Studies and Randomized Controlled Trials: The Case of Cognitive Bias Modification and Alcohol Use Disorders

Abstract

NIH) redefined clinical trials to include any study involving behavioral or biomedical interventions. In line with a general framework from experimental medicine, we argue that it is crucial to distinguish between experimental laboratory studies aimed at revealing psychological mechanisms underlying behavior and randomized controlled trials (RCTs) in clinical samples aimed at testing the efficacy of an intervention. Method: As an illustration, we reviewed the current state of the evidence on the efficacy of cognitive bias modifi cation (CBM) interventions in alcohol use disorders. Results: A recent meta-analysis "cast serious doubts on the clinical utility of CBM interventions for addiction." That analysis combined experimental laboratory studies and RCTs. We demonstrated that, when studies are differentiated regarding study type (experimental laboratory study or RCT), mode of delivery (controlled experiment or Internet), and population (healthy volunteers or patients), the following effects are found: (a) short-lived effects of CBM on drinking behavior in experimental laboratory studies in students, but only when the bias is successfully manipulated; (b) small but robust effects of CBM on treatment outcome when administered as an adjunct to established treatments in clinical settings in RCTs with alcohol-dependent patients; and (c) nonspecific effects (reduced drinking irrespective of condition) in RCTs of CBM administered online to problem drinkers. Conclusions: We discuss how CBM might be improved when it is better integrated into regular treatment, especially cognitive behavioral therapy, and we conclude that disregarding the difference between experimental laboratory studies and RCTs can lead to invalid conclusions.

Do smokers devaluate smoking cues after go/no-go training?

“…A possible add-on to GNG trainings is attentional bias modification (ABM), in which the attention of participants is trained away from the targeted stimuli (i.e., smoking pictures) and towards neutral or control stimuli. Studies have shown some promise of ABM in the alcohol (Wiers, Boffo, & Field, 2018) and smoking (Elfeddali, De Vries, Bolman, Pronk, & Wiers, 2016) domain, but the combination of GNG and ABM training seems more effective in boosting intervention effects (Stice, Yokum, Veling, Kemps, & Lawrence, 2017;Wiers et al, 2018). In these kinds of interventions, participants are trained towards healthy behaviours (such as healthy food) by ABM, and trained to not respond to unhealthy behaviours (such as snack foods) by GNG training.…”

A transdiagnostic dimensional approach towards a neuropsychological assessment for addiction: an international Delphi consensus study

“…Nevertheless, with the exception of some developments such as cognitive-bias modification [42], current approaches to clinical assessment and management have largely failed to integrate these developments into assessment and intervention tools. Two principal barriers to translation remain: (i) psychiatric assessment and diagnostic tools are based largely on characterization of symptoms (versus mechanisms), predicated on clinical reliability rather than biological validity, and based on self-reports and observable behaviours rather than empirically measured dimensions; and (ii) neuropsychological assessments (as applied in the clinic) are based typically on paradigms developed decades ago for use in brain lesion cases and neurological disorders, which may lack sensitivity to the specific cognitive-emotional constructs key to the psychopathology of addiction.…”

A Randomized Trial of Combined tDCS Over Right Inferior Frontal Cortex and Cognitive Bias Modification: Null Effects on Drinking and Alcohol Approach Bias

“…However, our results are consistent with a large study that attempted to replicate CBM findings in 2 large samples (Lindgren et al., ); of note, the sample included here was very similar to that of Lindgren and colleagues (), who included participants that were non–treatment‐seeking drinkers reporting at least 1 binge drinking episode in the past month. Wiers and colleagues () have argued that training effects may only be useful in treatment‐seeking samples, who are highly motivated to change their drinking and also may have greater implicit biases prior to treatment. Participants in the current trial were not informed that the study was an intervention trial to reduce drinking and were excluded from participating if they were seeking treatment, so it seems unlikely that there would be any motivation to change, which could be an important factor in predicting training effects (Boffo et al., ; Lindgren et al., ).…”

“…The results for the verum CBM conditions are somewhat surprising given initial promising findings for reducing relapse, but given that the current sample was not a treatment‐seeking sample, the present null finding is not necessarily evidence against using approach bias modification interventions. In addition, because the proposed mediating factor in drinking reductions (i.e., approach bias toward alcohol) did not change, changes in drinking should not be expected (Wiers et al., ). While there have been a reasonable number of studies investigating CBM for AUDs, far fewer studies have examined tDCS as a potential treatment.…”