Addiction Medicine: Closing the Gap between Science and Practice

Chapter II

What Is Addiction?

Addiction* is a complex brain disease with

significant behavioral characteristics.^1 In many

but not all cases, it involves the use of nicotine,

alcohol and other drugs.† Addiction involving

these substances typically originates with use in

adolescence when the brain is still developing

and is more vulnerable to their effects.^2 If

untreated, it can become a chronic and relapsing

condition, requiring ongoing professional

treatment and management.^3

Although there has been an evolution in

scientific understanding of the disease, public

attitudes and health care practice have not kept

pace with the science. Terms used to describe

different levels of substance use and addiction’s

many forms lack precision, obscuring important

differences in the use of addictive substances

and the nature and severity of the illness and

complicating our ability to treat it effectively.

* In this report, we have used the general term

addiction to apply to those who meet criteria for past-

month nicotine dependence based on the Nicotine

Dependence Syndrome Scale (NDSS) and those who

meet diagnostic criteria for past year alcohol and/or

other drug abuse or dependence (excluding nicotine)

in accordance with the Diagnostic and Statistical

Manual of Mental Disorders (DSM-IV). (The DSM

refers to substance abuse and substance dependence

as substance use disorders. The criteria for nicotine

dependence in the NDSS parallel those of the DSM-

IV.) This definition is consistent with the current

move to combine abuse and dependence into an

overarching diagnosis of addiction in the upcoming

DSM-V.

† Other drugs include federally controlled illicit drugs

and the misuse of controlled prescription drugs. The

term addiction also has been used in reference to

compulsive behaviors involving eating, gambling and

other activities that affect the brain’s reward system

and which may develop independent of or in

combination with other manifestations of addiction.

This report, however, focuses only on addiction

involving nicotine, alcohol and other drugs.