There is disagreement in the scientific community regarding the adequate terminology for defining the term of problematic Internet use. The most common names that can be found in the literature dealing with this issue are: Internet addiction, problematic Internet use, compulsive Internet use, pathological Internet use. The term Internet addiction is used by authors who generally regard this phenomenon a disorder with serious consequences to physical and mental health of the individual, including their social, academic and work performance. Block (Block, 2008, according to Chang and Hung, 2012) proposed the inclusion of the term 'Internet addiction disorder' in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders of the American Psychiatric Association (DSM-V). Despite the fervent debate in the psychiatric and psychological circles on the matter, the term 'Internet addiction' was not included in the classification system of Diagnostic and Statistical Manual of Mental disorder – fifth edition, released in 2013. The manual describes only the term 'Internet gaming disorder' as a condition that requires further research before it is officially recognized as a diagnosis (Diagnostic statistical manual of mental disorders, 2013). 

American psychologist Kimberly Young (Young, 1998a) is a pioneer in diagnostic defining and research of problematic Internet use. Back in 1996 she described Internet addiction as a disorder of impulse control, which is in its compulsive nature most similar to pathological gambling (Young, 1998a), and includes the following symptoms:  

• preoccupation with the Internet (thinking about previous activities on the Internet or anticipating the next ones);
• tolerance to the use of the Internet (the need for using the Internet for a longer period of time to achieve the same level of satisfaction as before);
• negative emotional reactions (anxiety, depression, irritability) in an attempt to reduce the use of the Internet or interruptions made while the Internet is being used;
• unsuccessful attempts to control, reduce or discontinue the use of the Internet;
• use of the Internet for a longer period of time than planned;
• endangerment of important social relations, work or school commitments because of the Internet;
• concealing the degree of involvement in activities related to the Internet;
• use of the Internet as a way to escape problems or alleviate negative emotional states, such as helplessness, guilt, anxiety, depression. 

A few years later Shapira et al (Shapira, Lessig & Goldsmith, 2003, according to Aboujaoude, 2010), proposed the term problematic Internet use instead of Internet addiction, taking it to be more adequate and defining it based on the following criteria: 

• maladaptive preoccupation with Internet use, seen as an irresistible urge to use it for longer periods of time than planned;
• significant distress or damage of functioning as a result of Internet use and;
• lack of psychiatric disorders that could explain excessive Internet use, such as mania or hypomania.

In spite of great number of studies in the field of compulsive Internet use, there is a relatively small body of theoretical explanations for the etiology of compulsive Internet use in the professional literature. Davis (Davis, 2001, according to Griffiths, 2008) distinguishes between specific and generalized pathological Internet use. Specific pathological use of the Internet refers to the excessive use of specific functions of the Internet and it is the result of psychopathology that had been presented before, which is associated with the activity on the Internet (e.g. compulsive gamblers who satisfy their need on the Internet). On the other hand, generalized pathological Internet use involves spending a lot of time on the Internet without a specific purpose and determining factor in its development is social context of the individual, especially a lack of social support and/or social isolation. 

Drawing upon Davis's theoretical stance, Caplan has proposed the following theoretical assumptions, which also received empirical support (Caplan, 2003): 

• people suffering from psychosocial problems (e.g. depression, loneliness) have a more negative perception of their social skills than people who do not suffer from this kind of difficulty;
• such persons develop a tendency towards social interactions on the Internet, because they find it less threatening than a direct ’face to face' form of communication;
• a tendency towards social interactions on the Internet leads to excessive and compulsive use of the Internet, which, in turn, aggravates their problems and creates additional difficulties at work, school, and in family. 

Among the most common etiological factors the following were examined: self-esteem, personality, presence of psychological problems, social support, family functioning. Many of these studies were carried out on samples of older school-age children and adolescents. As for our and neighboring countries, according to the available literature research that investigate risk factors of the phenomenon problematic Internet use are very scarce. 

In a number of studies that have been carried out on adolescents and young adults, it was found that low self-esteem is associated with problematic Internet use (Aydin & Sari, 2011; Yao, He, Ko & Pang, 2014). Recent studies give evidence to support the assumption that Internet dependence and other types of addictive behavior (such as pathological gambling) have the same psychological background, or that the psychological profile of addicts contains the same features, such as high levels of stress, loneliness and low social support (Dowling & Brown, 2010, according to Flora, 2014). A representative research conducted on a sample of 12,000 adolescents in 11 European countries (Durkee et al., 2012, according to Flora, 2014) has shown that poor parental involvement and parental unemployment, and the lack of emotional and psychological support represent important risk factors for the occurrence of pathological and maladaptive Internet use.