Despite growing interest in internet addiction (IA), there is still no consensus in perceiving it as a distinct clinical disorder. Proposals of including IA in the DSM-V and possibly also ICD-11 have strengthened the notion that it has a lot of features justifying its nosological classification as a primary disorder.

Besides a large number of epidemiological surveys, clinical examinations investigating psychopathological symptoms and co-morbidity in a standardized way are still missing. Hence, clinical data is very important in the research on IA as it might support data gained in representative studies.

The purpose of the study was to provide further clinical characterisation of IA.

A clinical sample from a specialized outpatient clinic in Germany was examined by clinical ratings (GAF; psychiatric co-morbidity) and questionnaires (SCL-90R, PHQ). Two clinical groups were included: Patients meeting criteria for IA (n=80) and patients with pathological gambling (n=80). For further statistical comparison, healthy controls (n=80) were recruited too.

Both clinical groups scored significantly higher in SCL-90R and PHQ than the controls. Patients with IA showed similar profiles in SCL-90R as pathological gamblers with no significant differences in any sub-scale. Also, scores of GAF were similar. Expert ratings on co-morbidity indicate that depression is associated with both disorders. In IA also social phobia is common.

Patients with IA and pathological gamblers display comparable levels of psychopathological symptoms and impairment. IA seems to cause significant psychopathological strain similar to pathological gambling that is accepted as a clinical disorder since the 1980ies.