Is drug abuse a disease?
To ask if drug abuse – that is, continuing to use drugs while failing to fulfil major role responsibilities, in dangerous situations, or while suffering legal or social consequences – is a disease, one must first understand how the word ‘disease’ is defined. ‘Disease’ is a word. Words can be defined in two ways. First, an intentional (rule-based) definition can be applied. There is great economy to this type of definition. For example, using simple maths one can ‘consider whole even numbers between 0 and 7’. The numbers are identified through a summary rule. Likewise, a disease can be defined through use of a summary rule. A disease may be defined as an outcome condition that involves impairment of bodily functions, resulting from exposure to a living or non-living object, that is mediated by some causal mechanism. For example, the flu is an outcome condition that involves antibody buildup and a high temperature. The sufferer often feels terrible and may not be able to work for a few weeks. It results from exposure to particles in the air or on surfaces, and is mediated by intake of a virus or bacteria. As another example, cardiovascular disease involves a closing up of vital cardiovascular organs. The sufferer may suffer a variety of consequences such as strokes or heart attacks that grossly restrict participation in daily activities. This disease results from intake of fatty foods, lack of exercise and cigarette smoking, among other factors. The operation of these factors on cardiovascular disease are mediated by some process that involves preparedness to wear down the cardiovascular system (heredity) and elicitation of gradual plaque buildup. If drug abuse is a disease, one may define drug abuse here as an outcome condition that involves negative social, legal, physical or functional consequences, that results from intake of a drug. Processes that involve heredity, changes in neurotransmitter homeostatic function or other unknown factors may mediate drug abuse.
The other definitional framework is the extensional (listing-type) definition. Using the same simple mathematical definition presented in the preceding paragraph, instead of presenting a rule one would list ‘2, 4, and 6’. In