Background: Problematic internet use has been described in the psychological literature as 'internet addiction' and 'pathological internet use'. However, there are no studies using face-to-face standardized psychiatric evaluations to identify behavioral characteristics, psychiatric comorbidity or family psychiatric history of individuals with this behavior. Methods. Twenty individuals with problematic internet use were evaluated. Problematic internet use was defined as (1)uncontrollable, (2) markedly distressing, time-consuming or resulting in social, occupational or financial difficulties and (3) not solely present during hypomanic or manic symptoms. Evaluations included a semistructured interview about subjects' internet use, the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders-IV (SCID-TV), family psychiatric history and the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) modified for internet use. Results: All (100%) subjects' problematic internet use met DSM-TV criteria for an impulse control disorder (ICD) not otherwise specified (NOS). All 20 subjects had at least one lifetime DSM-IV Axis I diagnosis in addition to their problematic internet use (mean+/-SD = 5.11-3.5 diagnoses); 14 (70.0%) had a lifetime diagnosis of bipolar disorder (with 12 having bipolar I disorder). Limitations: Methodological limitations of this study included its small sample size, evaluation of psychiatric diagnoses by unblinded investigators, and lack of a control group. Conclusions: Problematic internet use may be associated with subjective distress, functional impairment and Axis I psychiatric disorders. (C) 2000 Elsevier Science B.V. All rights reserved.
