Are we compulsively chasing rainbows?
Olivier George, Serge H. Ahmed, Nicholas W. Gilpin
Abstract
Addiction is commonly defined as a chronic, relapsing disorder characterized by taking drugs in excess, compulsive drug seeking, and continued use despite harmful consequences (NIDA, SAMSHA) despite the fact that the word "compulsive" is not explicitly stated in the DSM-or ICD-based diagnostic classification of substance use disorders (SUD), and that the role of compulsivity in addiction remains highly debated Similarly, in the preclinical addiction field, the idea that the only way to identify an individual with addictionlike behaviors is to measure compulsive drug use/drug seeking is pervasive and often treated as the only approach for studying neuropharmacological mechanisms relevant to addiction. Recently, the addiction neuroscience field has moved from recognizing that "compulsive drug seeking/use" and "continued seeking/use despite negative consequences" are two distinct aspects of addiction to defining the former nearly exclusively by the latter [2-7]. In our opinion, this informal but pervasive re-definition of compulsion has sacrificed construct validity for operationalization, and a direct consequence of this re-definition is that continued drug use (or seeking) despite punishment (e.g., painful footshock or bitter tastants) is widely considered the behavioral hallmark for compulsive-like drug-seeking behavior in preclinical models. We believe that over-reliance of addiction neuroscientists (including ourselves) on this measure hinges more on experimental convenience (i.e., testability) than on construct validity, and we also believe that over-reliance on this approach may be detrimental to the field. Here, we highlight several issues associated with the definition of compulsivity in addiction, problems associated with the regard for compulsivity as the defining feature of addiction, and the existence of conceptual and methodological limitations in preclinical studies. We also suggest ways for the field to move forward from the current position. Note that 'drug' in this commentary is a generic term that refers to alcohol, nicotine, and tobacco products, and illicit drugs.