Making Sense of Drug Addiction

June 3, 2014

We all know we’re supposed to make choices that are good for our long-term health, although that’s not easy when we’re faced with things that bring us pleasure right now. But for some people, the short-term benefits often win out over the long-term ones. That can help explain why some people get addicted to drug use and other risky behaviors – and why it’s so hard to get them to stop, according to Matthew Johnson, associate professor of psychiatry and behavioral sciences at Johns Hopkins School of Medicine. 

People who are addicted to drugs are more likely than non-users to prefer small, immediate rewards over larger and more-lasting benefits, Johnson’s research finds. This is called delay discounting, because it involves devaluing benefits that occur after some delay in time. For example, research participants who are addicted to drugs are more likely to say they would choose a small sum of money right away rather than waiting for a larger sum. This isn’t surprising, Johnson says, because it is akin to choosing a short-term drug high over longer term benefits like better health and relationships. Excessive delay discounting is common among people addicted to “virtually all drugs of abuse including cigarettes,” he explains, and he has found that it is also common among individuals who have unprotected sex with new partners. 

Because of excessive delay discounting, simply stressing the long-term benefits of getting clean – or the consequences of continuing the addictive behavior – often isn’t enough to stop drug abuse. “Many drug-addicted individuals will tell you they don’t want to be using in a year, but if the drug is in front of them an hour later, they will take it,” Johnson points out. That’s because, “even if they recognize the long-term benefits of abstaining, they aren’t sensitive to” or motivated by those benefits. 

Instead, Johnson says, clinicians should identify drug abusers who engage in extreme delay discounting and use treatments that target it. As an example, he cites a treatment for cocaine addiction called contingency management, which was not developed with delay discounting in mind but inherently addresses it. In this treatment, patients receive rewards for drug free urine samples (such as $20 vouchers), which he describes as “artificial short-term incentives to help patients become sensitive to benefits that accrue over time.” This can help patients get to the point of experiencing the long-term “naturalistic” consequences of improved health, finances, and family relationships. 

Johnson is hopeful that his research can help identify other treatment strategies. He currently has a grant to study whether and why improving working memory – through tasks like holding a sequence of numbers in mind – can reduce delay discounting and potentially enhance other treatment options. 

His research also has implications for prevention and public health efforts. In recent studies, he has examined delay discounting in sexual risk-taking among cocaine abusers, who have high rates of HIV infection and transmission. He has found that many cocaine abusers said they would use a condom with a new sexual partner if one were immediately available, but they were unlikely to delay sex in order to get a condom – especially with a highly desirable sexual partner. The take-home message, he says, is that “it would make a huge difference if you can get them to carry condoms on them.” 

No one knows why some people are more likely to engage in excessive delay discounting than others, but Johnson believes that a predisposition to it can cause a vicious cycle, because risky behaviors can expose people to situations, like financial hardship or drug withdrawal, that make immediate gratification even more appealing. His research suggests that understanding and remediating extreme delay discounting may be one key to breaking that cycle. 

Matthew Johnson was recently honored with the Federation of Associations in Behavioral & Brain Sciences (FABBS) Foundation Early Career Impact Award during the Association for Behavior Analysis International meeting in Chicago, Illinois.