Drug Image Gallery
Drug Image Gallery

Our understanding of addiction, including dependency on substances like heroin (shown above), has increased tremendously over the past three decades. See more drug pictures.

Photo Paula Bronstein/Getty Images

Stories about how addiction has ruined lives are common in our society today. Reports of the lengths addicts will go to and the dark acts they will commit to get drugs, like crack cocaine, heroin and even alcohol, abound -- serving as cautionary tales to keep others from following the same path.

­­There are many questions about the nature of addiction. Is denial a good indicator of addiction? Are some drugs as addictive as people say? There are even questions when it comes to drug- and alcohol-use prevention tactics. In order to persuade a person not to use a substance, the pitfalls of addiction are sometimes overstated. Overexaggeration can cause feelings of distrust.

Perhaps the best approach to the prevention of substance abuse is a clear, concise understanding of the process of addiction and the effects it can have on the user. To that end, researchers have arrived at a trim and science-based view of addiction. We have learned much in the last few decades, including the idea that addiction can come not only from abusing substances, but also with behaviors like sex and eating.

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Though we've come far in the study of addiction, it's still a relatively new concept. Just a few hundred years ago, and for centuries before that, the general attitude toward alcohol was that it was consumed because people wanted to consume it, not because of any internal or external necessity [source: Levine]. But as reports and confessions came in from people who felt an irresistible urge to consume alcohol and drugs (once they became more accessible), our idea about some substances changed, and we developed the concept of addiction.

It was originally believed that some substances, like alcohol and, later, opium, possessed addictive properties, meaning their contents were to blame. That idea later shifted, and addiction was believed to be part of the addict's character. Dependence on drugs and alcohol was seen as a personality flaw -- that the person couldn't behave himself. Later, addiction came to be seen as something from which a person suffered, like a disease.

Although we know that certain substances act on the brain in ways that make the individual want to use more, drug addicts and alcoholics are still widely considered by society to be depraved; after all, they chose to use drugs in the first place. And with all of the data available and medical advances achieved in identifying the different aspects of alcohol and substance abuse, science is still struggling with some key questions, like whether it's ultimately substances that are addictive or people who are addicted to substances -- or both.

In this article, we'll examine the current ideas about addiction and look at the ways science is continuing its research to understand, once and for all, the mystery of addiction.