How Does Delay Discounting Affect the Behavior of Cocaine Addicts?
Throughout early childhood and adolescence, humans gradually develop the ability to do such things as think logically, compare past experiences to present experiences, control momentary impulses, make decisions, make plans for the future and take the steps required to turn previously established plans into reality. By the time any individual reaches his or her 20s, this ability - referred to as executive function - typically reaches its full development.
Executive function is necessary to weigh the pros and cons of short- versus long-term rewards and short- versus long-term losses. For example, a person who has a long-term goal of getting healthy must measure the ultimate rewards of achieving this goal against the immediate rewards of eating high-fat or high-sugar foods, an activity that can undercut the quest for health if undertaken with any regularity. Similarly, a person must decide if acceptance of a short-term financial loss is preferable to the looming but potentially avoidable possibility of a larger financial loss at a later time. The basic principle of delay discounting holds that humans naturally prefer immediate, short-term outcomes and de-emphasize or discount the worth of long-term outcomes.
Discounting, Substance Abuse and Substance Addiction
All classic substances of abuse access the brain’s pleasure center and produce varying degrees of an intense sensation called euphoria. As a rule, the euphoria associated with substance use far outweighs the pleasure associated with such typically desirable activities as having sex or eating satisfying food. In practical terms, this means that a certain percentage of substance users will repeatedly seek out the rewarding feelings linked to drug or alcohol intake and ultimately undergo changes in brain function that trigger a reliant state called physical dependence. Depending on the substance in question, physical dependence is either synonymous with substance addiction or the precursor to substance addiction. In a substance abuser or substance addict, delay discounting can heavily sway behavior toward the short-term rewards of drug or alcohol consumption and lead to relatively extreme de-emphasis of the physical and mental costs of abuse and addiction.
Impact on Addicted Cocaine Users
In the study scheduled for publication in Addictive Behaviors, the Johns Hopkins University researchers examined the delayed discounting behaviors of 89 adults affected by cocaine dependence/addiction. In addition to employing standard psychological testing procedures—which use financial incentives to measure preferences for short- versus long-term rewards—the researchers also directly tested the study participants’ willingness to trade off short-term intake of relatively small amounts of cocaine for the later opportunity to consume larger quantities of the drug. They also tested the participants’ willingness to lose small quantities of money or cocaine in the present in order to avoid potentially losing larger quantities of money or cocaine in the future. The researchers chose to directly measure drug-related delay discounting, in part, because most addicted users value drugs more than they value the money required to pay for drugs.
The researchers concluded that the addicted cocaine users were far more willing to accept smaller, short-term financial rewards and cocaine rewards than they were to accept short-term losses of money or cocaine. The willingness to accept short-term (versus long-term) cocaine rewards was greater than the willingness to accept short-term (versus long-term) financial rewards. Conversely, the participants displayed roughly equal unwillingness to accept short-term losses of money or cocaine in order to avoid larger losses at a later date.
The study’s authors believe their findings may indicate that the delayed discounting addicted users apply to cocaine intake may be part of a more general pattern of preferring tangible short-term rewards over possible longer-term rewards. They also believe their findings may indicate that, when it comes to determining the immediate behavior of addicted cocaine users, the desire to avoid losing even relatively small amounts of the drug may play a more important role.