Introduction

The internet has become an integral part of adolescents’ lives. Children and young people are engaging in a broad range of activities online, chatting with friends, playing online games, watching videos, listening to music, doing schoolwork, browsing for information, etc (Subrahmanyam and Smahel, 2010). The rapid increase in fast and cheap internet connections since the end of the 1990s has helped to increase the amount of time individuals spend online. Adolescents growing up in the contemporary digital era are among the most prominent internet users and more frequent users than among the older age categories (Lupac and Sladek, 2008). Their online and offline lives are strongly interconnected (Subrahmanyam and Smahel, 2011).

The increased time spent online is prompting questions about whether all individuals are in control of their increasing internet usage. Excessive time spent online has been deemed to influence several aspects of youths’ lives: declining school results or even dropping out of school; increased family tension; abandoned hobbies; psychological problems such as depression, anxiety and low self-esteem; and physical health problems due to sleep deprivation and lack of physical activity (Young, 1996; Shapira et al, 2000).

The term ‘internet addiction’ emerged when the above-mentioned negative outcomes began to be associated with repetitive, compulsive and uncontrollable use of the technology. Different researchers use different terms to describe the same or similar phenomena: pathological internet use (Young, 1996, 1998), problematic internet use (Shapira et al, 2000), internet addiction disorder or addictive behaviour on/to the internet (Widyanto and Griffiths, 2006). In this chapter we use the term ‘excessive internet use’ to describe this phenomenon.

Although there is agreement about how to describe the symptoms of this phenomenon, researchers are not agreed about the extent to which it can be considered an addiction and, thus, a pathology. Widianto and Griffiths (2006, 2007) maintain that it is unclear when speaking about excessive internet use how often the technology is blamed for causing the problem versus how much the technology is mediating problems with origins elsewhere. Also, excessive internet use is not acknowledged as an official disorder and is not included in diagnostic manuals, for example, in the American Psychiatric Association Diagnostic and Statistical Manual IV (DSM IV), and will also not be included in the revision DSM V (Block, 2008).