**Project goals**
1. to validate the existing measurement of the nine IGD criteria
presented in DSM-5 and ICD 11. To propose and to validate
measurement of new criteria developed on the basis of alternative
IGD theories and qualitative phenomenological study;
2. to identify which of the symptoms (criteria) are central and which
are peripheral using the network approach, identify their
strength, relationships and their pervasiveness;
3. to identify IGD risk factors and simultaneous occurrence of symptoms of
multiple disorders in a longitudinal study;
4. to develop and validate new questionnaire measuring IGD through its
symptoms.