Recurrent use of a substance, or engagement with an activity, that leads to impairment or distress, is the core of addictive disorders. The clinical diagnosis of an addiction is based on the presence of at least two of a number of features:
The substance or activity is used in larger amounts or for a longer period of time than was intended.
There is a desire to cut down on use or unsuccessful efforts to do so.
Pursuit of the substance or activity, or recovery from its use, consumes a significant amount of time.
There is a craving or strong desire to use the substance or engage in the activity.
Use of the substance or activity disrupts obligations at work, school, or home.
Use of the substance or activity continues despite the social or interpersonal problems it causes.
Participation in important social, work, or recreational activities drops or stops.
Use occurs in situations where it is physically risky.
Use continues despite knowing it is causing or exacerbating physical or psychological problems.
Tolerance occurs, indicated either by need for markedly increased amounts of the substance to achieve the desired effect or markedly diminished effect of the same amount of substance.
Withdrawal occurs, manifest either in the presence of physiological withdrawal symptoms or the taking of a related substance to block them.
The severity of the condition is gauged by the number of symptoms present. The presence of two to three symptoms generally indicates a mild condition; four to five symptoms indicate a moderate disorder. When six or more symptoms are present, the condition is considered severe.