Most drugs of abuse are addictive. Addiction is a chronic, relapsing disease characterized by compulsive drug seeking and use despite negative consequences and by long-lasting changes in the brain. People who are addicted have strong cravings for the drug, making it difficult to stop using. Most drugs alter a person’s thinking and judgment, which can increase the risk of injury or death from drugged driving or infectious diseases (., HIV/AIDS, hepatitis) from unsafe sexual practices or needle sharing. Drug use during pregnancy can lead to neonatal abstinence syndrome, a condition in which a baby can suffer from dependence and withdrawal symptoms after birth. Pregnancy-related issues are listed in the chart below for drugs where there is enough scientific evidence to connect the drug use to negative effects. However, most drugs could potentially harm an unborn baby.
Unfortunately, marijuana producers have a strong incentive to hook young users. While about 9 percent of adults who use cannabis become addicted, the rate is 17 percent for people who start smoking in their teens, according to NIDA figures. And as the tobacco and alcohol industries have demonstrated, she says, such companies make the majority of their profits on a relatively small proportion of chronic users. "The minute there's a profit motive, companies tend to make a product more addictive," says Lisdahl. "I think legalization is moving ahead prematurely without considering the lessons we've learned from nicotine and alcohol prevention policy research."