The concept of being addicted to Internet screen devices has evolved over the last 25 years but there is little question that Internet use can be addictive. A study conducted by Dr. Kimberly Young in 1997 found early on that excessive use of the Internet was associated with detrimental effects to academic and professional performance. My original study published in 1999 and conducted in cooperation with ABC News found that approximately 6% of those who use the Internet seem to do so compulsively— often to a point of them experiencing serious negative consequences. We found several key factors that seem to contribute to becoming addicted to these technologies. The addictive factors are accessibility, affordability, time distortion, interactivity, anonymity, and content stimulation. This is in addition to the potent presence of a variable reinforcement dopamine reward schedule. Since this early research, there have been hundreds of studies supporting the addictive nature of the Internet.

Many intoxicating behaviors and substances that produce pleasurable effects, e.g. elevations in the neurotransmitter dopamine, tend to be repeated. The repetition of such pleasurable behaviors despite potential negative consequences is well established in the literature. What we find with Internet addiction particularly, is that it seems to mimic the same phenomena that occurs with addiction to other pleasurable (and addictive) substances and behaviors. Internet addictions seem to follow a pattern of variable reinforcement, as previously noted, and this reinforcement schedule means that a reward through our Internet use behavior, is often unpredictable in terms of what you find or experience, how desirable it will be, and when it will occur. Concerning the Internet, the reward can come in the form of receiving a desirable email, a text, a social media like or comment, an interesting piece of information, a photo or You Tube video, or a video game–virtually any desirable and pleasurable content.

It is irrelevant what the pleasurable stimulus is. The most relevant factor is that the degree of pleasure received is in part mediated by the novelty, unpredictability, and power of that reinforcement. The variability and unpredictability (just like gambling on a slot machine) is what produces the strong habit or addiction. Therefore, people spend hours and hours on the Internet looking for that hit—all the while rationally knowing that they are wasting their time. These pleasurable hits lead to the acceleration of the elevation of dopamine and the potential for an addictive pattern of behavior. There have been numerous neurobiological studies with scans demonstrating similar dopamine responses to substances when looking at the reward/pleasure centers of the brain’s response to video games, Smartphone, and Internet use.

The goal is to maintain mindful and sustainable use of our Internet and screens; for most of us this is not a problem, but for a growing number of people, the Internet has become the latest drug of choice.