Abstract
Aims: A new theory of substance dependence is presented that models dependence as the absence of cognitive constraints on substance use.
Methods: (1) Critical review of the predominant paradigm that assumes that substance dependence is a pathological state fundamentally caused by the neuropsychopharmacological effects of drugs (NPP paradigm) identified four counter-factual assumptions. Contrary to the NPP paradigm: (I) dependence can occur on a-typical substances and other things; (II) dependence is a complex, gradated phenomenon, not a state; (III) heavy protracted substance use can occur without dependence; and (IV) NPP interventions against dependence have not worked other than as drug substitutes. (2) Reconceptualisation of dependence as substance use with few cognitive, behavioural or social constraints. (3) Development of an exhaustive list of constraints on substance use with a panel of experts, achieving theoretical saturation. (4) Modelling of dependence, specifically to explain why socioeconomic deprivation is correlated with substance dependence.
Results: Fifteen common constraints are described, which prevent most substance users becoming dependent. People in more socioeconomically deprived conditions tend to have fewer constraints. Similarities between Constraint Theory and previous sociological and social cognitive theories are discussed.
Conclusions: Constraint theory describes the known nature of substance dependence better than theories from the NPP paradigm. Conceptualising dependence as an absence of constraints shows promise as a theory of addiction and fits with existing knowledge about what works to prevent and treat substance dependence.