Several epidemiological studies revealed prevalence-rates of Internet Addiction (IA) - which was currently proposed as an independent disorder for DSM-5 - ranging from 0.5 to 1 per cent. Above all, patients with IA show psychopathological patterns (craving, tolerance, withdrawal, mood modification, relapses) comparable to substance-related disorders. Besides, IA is frequently accompanied by various comorbidities, such as anxiety, depression or personality disorders.

The aim of the present study was to assess typical clinical characteristics and disorder-specific cognitive styles in a subgroup of patients with IA and an underlying Borderline Personality Organization (BPO) in a consecutive sample of over 450 treatment-seekers in an Outpatient Clinic for Internet and Computer game Addiction.

20 patients, who fulfilled both: the diagnostic criteria of IA and a Borderline Personality Disorder were compared with a matched control-group of BPO-patients without psychopathological but extensive Internet use. Both groups were assessed with the FGG (Questionnaire on borderline-specific cognitions and feelings, Renneberg et al., 2004) and further psychological features (e.g. global assessment of functioning (GAF), self-efficacy (SWE) and sensation seeking).

BPO-patients with IA show an increased mean of the total score of the FGG as well as of further clinical measures. The results lead to the assumption, that BPO-patients with IA use more disorder-specific cognitions, show higher mental strains and lower levels of health-related well-being compared to BPO-patients with only an extensive internet use.

Internet addictive behavior in BPO-patients may serve as avoidance behavior in order to subdue the burden of the primary disease.