People who grow up in homes in which parents
routinely expose their children to smoking,
excessive drinking or other drug use are at
increased risk of substance use, as are those
whose parents do not convey strong anti-
substance use messages and expectations.^68 The
nature of the parent-child relationship is key;
people who come from families with high levels
of parent-child conflict, poor communication,
weak family bonds and other indicators of an
unhealthy parent-child relationship are at
increased risk of substance use and addiction.^69
Individuals whose peers engage in substance use
or convey approval of such use are at increased
risk as well.^70
The simple fact of availability of addictive
substances makes it likelier that an individual
will use them.^72 Homes where liquor and
medicine cabinets are open to teens increase the
chances that teens will use these substances.^73
People who live in communities where addictive
substances are readily available, where using
such substances is considered normal or
expected or where tobacco and alcohol retail
outlets are prevalent are at increased risk.^74
Widespread access to controlled prescription
drugs contributes to the misuse of these
substances^75 and increased access to marijuana
marketed as medicine is linked to increased
use.^76 Community tolerance of high levels of
substance use or of experimenting with and
using addictive substances as a normal rite of
passage for adolescents also increases the risk of
use, as does lax enforcement of governmental
policies and regulations restricting use.^77
Exposure to advertising and marketing messages
that promote or glamorize smoking and drinking
increases the chances that these substances will
be used and misused.^78 Direct-to-consumer
marketing of controlled prescription drugs may
encourage substance use by conveying the
message that there is a pill for every ill.^79
Environmental influences can exacerbate
existing genetic, biological and psychological
risks for substance use, further increasing the
chances that an individual will engage in risky
substance use, sometimes to the point of
addiction.^80
Early Initiation of Use ..................................................................................................
Adolescence is the critical period of
vulnerability for the onset of substance use and
the development of addiction.^81 In 96.5 percent
of cases, addiction originates with substance use
before the age of 21.^82 Because the parts of the
brain responsible for judgment, decision-
making, emotion and impulse control are not
fully developed until early adulthood,
adolescents are more likely than adults to take
risks, including experimenting with addictive
substances.^83 At the same time, because these
regions of the brain are still developing, they are
more vulnerable to the negative impact of
addictive substances, further impairing
judgment, interfering with brain development
and increasing the risk of addiction.* 84 The
combination of early initiation of use and
genetic, biological, psychological or
environmental risk factors dramatically hike the
chances that addiction will develop.^85
Adolescents with a genetic predisposition to
addiction and/or co-occurring mental health
problems are at the greatest risk of progressing
from substance use to addiction.^86Risky Use and Addiction Frequently Co-Occur with Other Health Conditions ................
Individuals with addiction are likely to have co-
occurring health conditions.^87 Smoking causes
bladder, esophageal, laryngeal, lung and oral
cancer.^88 From 2000-2004, the top three causes
of smoking-attributable death were lung cancer,* As is true of much of health research, the research
on the neurological effects of addictive substances on
the adolescent brain primarily has been conducted on
animals.... [addiction] is not simply a disease of the
brain, but it is a developmental^ disorder, and it
begins early in life--during^ adolescence.^71--Nora D. Volkow, MD
Director
National Institute on Drug Abuse (NIDA)