The DSM-5 introduced a paradigm shift concerning addictive disorders by including gambling disorder, a non-substance-related disorder, in the Substance-Related and Addictive Disorders section. The inclusion of gambling disorder in this section of the DSM-5 opened the door for research of other non-substance-related disorders such as problematic Internet usage. With the proliferation of the Internet into almost every aspect of our lives, there is a need to study the potential addictiveness and the risk factors associated with this technological phenomenon. This study used a validated problematic Internet usage instrument, the Problematic Internet Use Questionnaire, to evaluate the correlation between problematic Internet usage and multiple at risk variables that could contribute to problematic Internet usage. These variables included worry, social anxiety, sensation seeking, neuroticism, and endorsement of self-medication. I hypothesized that problematic Internet usage scores on the Problematic Internet Use Questionnaire would be higher for individuals endorsing higher scores on the at risk variables mentioned above (worry, social anxiety, sensation seeking, neuroticism, and endorsement of self-medication). To examine this hypothesis, a forced entry multiple regression analysis was conducted to assess the simultaneous effects of worry, social anxiety, sensation seeking, neuroticism, and self-medication on problematic Internet usage while also controlling for age and gender. All measured variables (age, gender, neuroticism, social anxiety, worry, sensation seeking, and endorsement of self-medication) except gender contributed toward problematic Internet usage. Neuroticism had the highest correlation with problematic Internet usage (r = .40, p, < .001), and it was the best single predictor (beta = .35, p = < .01) of problematic Internet usage among all other predictor variables (social anxiety, worry, sensation seeking, and self-medication). The study included a sample of 206 Internet users from North America (128 females and 78 males) with an age range from 16 to 68 years. The mean age of the participants was 35 years with a SD +/- 11 years.