Background The US National Institutes of Mental Health Research Domain Criteria (RDoC) seek to stimulate
research into biologically validated neuropsychological dimensions across mental illness symptoms and diagnoses.
The RDoC framework comprises 39 functional constructs designed to be revised and refined, with the overall goal
of improving diagnostic validity and treatments. This study aimed to reach a consensus among experts in the
addiction field on the ‘primary’ RDoC constructs most relevant to substance and behavioural addictions.
Methods Forty-four addiction experts were recruited from Australia, Asia, Europe and the Americas. The Delphi
technique was used to determine a consensus as to the degree of importance of each construct in understanding
the essential dimensions underpinning addictive behaviours. Expert opinions were canvassed online over three rounds
(97% completion rate), with each consecutive round offering feedback for experts to review their opinions.
Results Seven constructs were endorsed by ≥ 80% of experts as ‘primary’ to the understanding of addictive
behaviour: five from the Positive Valence System (reward valuation, expectancy, action selection, reward learning,
habit); one from the Cognitive Control System (response selection/inhibition); and one expert-initiated construct
(compulsivity). These constructs were rated to be related differentially to stages of the addiction cycle, with some
linked more closely to addiction onset and others more to chronicity. Experts agreed that these neuropsychological
dimensions apply across a range of addictions. Conclusions The study offers a novel and neuropsychologically
informed theoretical framework, as well as a cogent step forward to test transdiagnostic concepts in addiction
research, with direct implications for assessment, diagnosis, staging of disorder, and treatment.