Cocaine Increases Risky Behaviors, Depending on Your Age

Cocaine is a psychostimulant drug that increases euphoria, energy, sociability, and mental alertness, improves physical and intellectual performance, decreases sleep, and decreases appetite. So, it is not surprising that over 2 million Americans reported using cocaine just last year. However, cocaine also has addictive properties. Hence, of the 2 million users, over half will meet the DSM-V criteria for abuse or dependence.

It is these individuals who are disposed to the effects of prolonged drug use, including changes in cardiovascular function, erratic and violent behaviors, irritability, anxiety, seizures, and, at times, even death. Chronic cocaine exposure has also been shown to change brain networks and how users control their behavior.

This is logical because our brains are meant to adapt to long-term changes in our chemistry and in our surroundings. In fact, for example, long-term exposure to cocaine can lead to desensitization of the brain’s reward pathway, such that tolerance develops. These individuals require higher and more frequent doses of the drug. They can become irritable, experience panic attacks, paranoia, and, at times, even psychosis.

Another potentially dangerous, and still poorly understood, outcome of chronic cocaine use is its effects on risk-taking behaviors. Several studies that examined those facing cocaine-use disorders, using a variety of risk-assessment tests, confirm that chronic cocaine use is linked to greater risk-taking. The explanations for this drug-behavior link, however, varies. Is cocaine increasing sensitivity to reward, such that it encourages choice of drug reward despite its potentially risky outcomes? Or does cocaine decrease sensitivity to negative outcomes in a way that it increases risk-taking behaviors?

Experimenters are working hard to untangle the answers to these questions. This effort has been helped by the development of an animal model of decision-making, the Risky Decision-making Task (RDT). The RDT measures an animal’s choice between a small food reward or a larger food reward that is accompanied by variable risks of punishment. Similar to human studies, studies using RDT show that cocaine-using animals are more likely to choose the riskier option of a larger food reward despite its accompanying risk of punishment.

Using this RDT model, recent studies by my colleague, Caitlin Orsini, in the Department of Psychology at The University of Texas at Austin, along with her former colleagues at The University of Florida, shed light on our understanding of how chronic cocaine exposure may impact risk-taking behaviors [1]. In this study, the experimenters set out to measure cocaine-induced changes in risky behavior by both male and female rats. To their surprise, however, neither cocaine administered by the experimenter nor cocaine self-administered by the rats had any impact on risky behaviors, regardless of sex. This was an understandably disappointing outcome for the study. You see, a cocaine-induced increase in risk-taking behaviors was a foregone conclusion. The experimenters were more interested in assessing risky behaviors between the sexes, and not whether cocaine increased the behavior per se. Yet they were unable to find changes in risky behaviors in either sex as a result of cocaine.

At this point, Orsini and her colleagues more carefully assessed their situation and thought through the approach being used for the experiments. In doing so, they discovered that the age of the animals being used for these experiments was considerably older than those used in previous tests. So next they set out to answer an exciting new question: Is it possible that the effects of cocaine on risky behaviors results from the age of exposure to the drug?

Indeed, they discovered that animals who took cocaine at a younger age were more susceptible to the effects of the drug on risky behaviors. This is to say that animals who took cocaine at an earlier age were more likely to develop riskier behaviors than were their older counterparts, who first took the drug at an older age.

The 2020 National Survey on Drug Use and Health reported the percentage of people suffering from a substance use disorder (SUD) was highest among young adults aged 18 to 25 (24.4 percent or 8.2 million people), followed by adults aged 26 or older (14.0 percent or 30.5 million people), and then adolescents aged 12 to 17 (6.3 percent or 1.6 million people). The age of initial exposure seen in these data make the implications of the findings in this study that much more significant, by showing that the age of drug exposure is an important contributing factor to the development of riskier behaviors, which in humans may include engaging in riskier sexual behaviors and criminal activities.