People who start drinking the soft drinks known as “energy” beverages early in life may be more prone to anxiety, depression, and addictive behavior later on, some research suggests.

Dr. Conrad Woolsey, an assistant professor of applied health and educational psychology at Oklahoma State University, has written several scholarly articles and lectured extensively on energy drinks.  He says the problem isn’t just that the drinks are packed with sugar and caffeine, but also with additives and herbal ingredients.

“Energy drinks are like a pharmacological Molotov cocktail,” Woolsey said.

He explains that because the human brain does not fully develop until the age of 25, it is more susceptible to being affected by the ingredients in energy drinks that influence the brain’s neurotransmitters–the chemicals that send information across a small gap, or synapse, from one nerve cell, or neuron, to another.

Circumstances both inside and outside of the brain determine which neurotransmitters get released. So pleasure-reward neurotransmitters, like dopamine, serotonin and endorphins, are released during pleasurable experiences and stress neurotransmitters and hormones, like cortisol and adrenaline, are released during intense experiences.

Caffeine’s ability to induce alertness, rapid heart beat and even jitteriness is well-documented, and energy drinks contain a lot of it. 

According to Woolsey, some of the ingredients commonly found in energy drinks, like taurine and inositol, have been used as anti-anxiety and antidepressant medications.  Along with the caffeine and ingredients such as ginseng, epinephrine, and guarana, they can simultaneously cause the release of pleasure-reward neurotransmitters and stress neurotransmitters.

As Woolsey explains it, energy drinks essentially simulate both a pleasurable and high-stress experience, at the same time.  The problem with that is the brain can become desensitized to otherwise normally pleasurable experiences due to these ingredients, so it takes ever-more artificial and natural stimulants for a person to feel satisfied or the same level of pleasure and reward–which Woolsey says can lead to addictive behavior.

He points to one study in which college students who drank three or four energy drinks a week were found to be more likely to illicitly use amphetamine-based attention deficit disorder medication.

Similarly, overstimulating the stress neurotransmitters at a young age can cause the brain to be overactive to them later–which can lead to anxiety and depression, Woolsey said.

Children are also more affected by caffeine than adults because they weigh less; a 100 pound person is going to be twice as affected by caffeine than a 200 pound person, Woolsey said.  “A kid (over-)using an energy drink(s) at [age] 12 would have a strong drive for addictive behavior later,” Woolsey predicts.

A survey conducted by Johns Hopkins University and the University of Maryland found that college students who regularly consume energy drinks are at a greater risk for alcohol dependency.

The study, published in the journal “Alcoholism: Clinical and Experimental Research,” involved interviews with 1,097 fourth-year students at a large public university.

Researchers found that “low-frequency” students, those who drank energy drinks 51 or less days out of the year, were significantly less likely to have alcohol-related problems than “high-frequency” students, those who drank energy drinks 52 or more days a year. The high-frequency students drank alcohol an average of 141.6 days a year compared with 103.1 days a year average for the low-frequency students. 

The high-frequency students also consumed a greater amount of alcohol. The high-frequency group consumed an average of 6.15 alcoholic drinks per drinking session, compared with the average of 4.64 alcoholic drinks consumed by the low-frequency group.

According to the researchers, while there is a strong correlation between daily or weekly energy drink consumption and alcohol dependence, further research is needed to understand the connection.

In response to the Johns Hopkins-University of Maryland article, the American Beverage Association, which represents several energy drink companies, said that an association between alcohol and energy drink consumption does not mean increased energy drink consumption leads to increased alcohol use.

The ABA declined a request for an interview for this article, but sent a written statement defending the safety of energy drinks.

The caffeine in energy drinks is no different from the caffeine in coffee, and some coffee may even contain more caffeine than energy drinks do, the ABA’s statement noted.

“Caffeine is one of the most thoroughly tested ingredients in the food supply today and has been deemed safe by the U.S. Food and Drug Administration, as well as more than 140 countries around the world,” the ABA said.

However, the ABA did not comment on the safety of the other ingredients in energy drinks.  Although caffeine at normal levels is considered relatively safe, the sale of caffeine pills to adolescents is regulated at dosages as low as 100 milligrams.  Also, as Woolsey has pointed out, it is the interaction between the multiple ingredients that increase the strength and risks to using energy drinks.