Conceptualizing addiction has been a matter of great debate for many years. For many scholars, the concept of addiction involves taking of drugs (e.g., Walker, 1989). Therefore it is perhaps unsurprising that most dictionary definitions focus on drug ingestion. However, there is now a growing movement (e.g., Grant et al., 2010; Griffiths, 2005; MacLaren & Best, 2010; Orford, 2001; Shaffer et al., 2004; van Rooij et al., 2010) that views a number of behaviours as potentially addictive, including those that do not involve the ingestion of a drug. These include behaviours diverse as gambling (Griffiths, 2006), eating (Meule & Gearhardt, 2014), sex (Carnes et al., 2005), exercise (Berczik et al., 2014), videogame playing (Griffiths et al., 2012), Internet use (Kuss et al., 2014a), mobile phone use (Billieux et al., 2015), social networking (Griffiths et al., 2014), love (MacLaren & Best, 2010), shopping (Maraz, Eisinger et al., 2015), and work (Andreassen et al., 2014), as well as more controversial behaviours such as studying (Atroszko et al., 2015), and dancing (Maraz, Urban et al., 2015). Such diversity has led to all encompassing definitions of what constitutes an addictive behaviour. One such definition is that of Marlatt, Baer, Donovan and Kivlahan (1988), who defined addictive behaviour as:
"A repetitive habit pattern that increases the risk of disease and/or associated personal and social problems. Addictive behaviours are often experienced subjectively as 'loss of control' - the behaviour contrives to occur despite volitional attempts to abstain or moderate use. These habit patterns are typically characterized by immediate gratification (short term reward), often coupled with delayed deleterious effects (long term costs). Attempts to change an addictive behaviour (via treatment or self initiation) are typically marked with high relapse rates" (p. 224).
The way of determining whether behavioural (i.e. non-chemical) activities are addictive in a non-metaphorical sense is to compare them against clinical criteria for other established drug-ingested addictions (Griffiths, 2008). Historically, this method of making behavioural excesses more clinically identifiable has been proposed for behavioural addictions such as "television addiction" (McIlwraith, Jacobvitz, Kubey & Alexander, 1991), "amusement machine addiction" (Griffiths, 1991) and “pinball addiction” (Griffiths, 1992). Further to this, authors such as Carnes (1991), Brown (1993) and Griffiths (2005) have postulated that addictions consist of a number of common components. Carnes (1991) outlined what he called the "signs of addiction" (see Table 1). To a large extent, these ten signs are subsumed within the components outlined by Brown (1993) and were later modified by Griffiths (1996; 2005). Griffiths’ (2005) most recent components of addiction comprise salience, mood modification, tolerance, withdrawal, conflict and relapse. These are described in more detail below with some relevant examples.