never opioid user

Parent class and superclasses all the way to to 'Entity'

This is an ontological definition of the entity using the standard format of specifying the parent class followed by specification of characteristics that distinguish this class from others in that class

This indicates whether the entity has fuzzy boundaries e.g. adolescence. In that case users of the term must precisely specify the operationalisation of the class in each usage.

Indicates the where the definition came from, either directly or in modified form

This specifies which of 8 AddictO sub-ontologies the entity is contained within. These are: Human being, Human population, Human behaviour, Organisation, Intervention, Environmental system, Product, Research activity