Many Factors are Involved in Addiction

Drug addiction shares many features with other chronic illnesses, including a

tendency to run in families (heritability), an onset and course that is influenced

by environmental conditions and behavior, and the ability to respond to

appropriate treatment, which may include long-term lifestyle modification.¹

Human studies of addictive behaviors have clearly implicated both environmental

and genetic influences, as well as interactions between the two. While genetics

play a major role in defining who we are, the environment in which we are raised

is just as influential.

Evidence from adoption and twin studies demonstrate that addiction, like

other chronic diseases, is a heritable disorder and that genes play a

role in vulnerability to addiction.

Genes can also play a role in protecting individuals from addiction.

As with all complex diseases, environmental risk and protective factors

interact with genetics to determine the course and outcome of disease.

Identifying and modifying environmental factors that contribute to health

and disease are part of NIDA’s mission, as well as that of the other

NIH Institutes and Centers.

Healthy Lifestyle Choices

Sometimes people do choose behaviors that have undesirable effects.

Personal responsibility and behavioral change are major components of any

credible treatment program. Addiction, like heart disease, cancers, and

type II diabetes, is a real and complex disease.

Addiction and Cardiovascular Disease Change Biology

Decreased Brain Metabolism in Drug Abuser

Sources: From the Laboratories of Drs. N. Volkow and H. Schelbert

Imaging studies have shown evidence of tissue malfunction in the brains of those

with addiction, and in the hearts of people with heart disease.