title: A contribution to the clinical characterization of Internet addiction in a sample of treatment seekers: validity of assessment, severity of psychopathology and type of co-morbidity.
abstract: OBJECTIVE
  Internet addiction becomes a growing health problem worldwide with prevalence rates up to 3%. Still, uncertainties exist regarding its diagnostics and clinical characterization. Especially the lacking clinical evidence regarding self-report measures assessing Internet addiction has been criticized.
  
  
  METHODS
  This study aimed to characterize 290 German treatment seekers and to determine the diagnostic accuracy of a self-report scale for Internet addiction. Patients filled in self-report measures (SCL-90R, PHQ, AICA-S - Scale for the Assessment of Internet and Computer game Addiction) and underwent diagnostic interviews to assess symptoms of Internet addiction and level of functioning.
  
  
  RESULTS
  Of the predominantly male treatment seekers 71% met the clinical diagnosis of Internet addiction. These displayed higher levels of psychopathology, especially depressive and dissociative symptoms. Half of the patients met criteria for one further psychiatric disorder according to clinical interviews, especially depressive disorders. Their level of functioning was decreased in all domains. AICA-S showed good psychometric properties and satisfying diagnostic accuracy (sensitivity: 80.5%; specificity: 82.4%).
  
  
  CONCLUSIONS
  In this sample, Internet addiction was associated with high levels of psychosocial distress that is mainly related to depressive symptoms. Co-morbid disorders were common among those patients. First analyses on diagnostic accuracy of AICA-S (using the therapist's rating on Internet addiction as an independent external criterion) showed promising results.
authors.affiliation: Outpatient Clinic for Behavioural Addictions, Department of Psychosomatic Medicine and Psychotherapy of the University Medical Centre of the Johannes Gutenberg University Mainz, Untere Zahlbacher Straße 8, 55131 Mainz, Germany.
authors.forename: K W
authors.initials: KW
authors.lastname: Müller
authors.affiliation: Outpatient Clinic for Behavioural Addictions, Department of Psychosomatic Medicine and Psychotherapy of the University Medical Centre of the Johannes Gutenberg University Mainz, Untere Zahlbacher Straße 8, 55131 Mainz, Germany.
authors.forename: M E
authors.initials: ME
authors.lastname: Beutel
authors.affiliation: Outpatient Clinic for Behavioural Addictions, Department of Psychosomatic Medicine and Psychotherapy of the University Medical Centre of the Johannes Gutenberg University Mainz, Untere Zahlbacher Straße 8, 55131 Mainz, Germany. Electronic address: muellka@uni-mainz.de.
authors.forename: K
authors.initials: K
authors.lastname: Wölfling
mesh_terms: D000328:Adult; D016739:Behavior, Addictive / Q000523:psychology*; D015897:Comorbidity; D003866:Depressive Disorder / Q000523:psychology; D005260:Female; D006801:Humans; D020407:Internet; D008297:Male; D001523:Mental Disorders / Q000523:psychology; D008875:Middle Aged; D015995:Prevalence; D011594:Psychometrics; D057566:Self Report; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D012919:Social Behavior; D063586:Social Validity, Research; D018910:Video Games