[Psychometric properties and initial validation of the questionnaire on differentiated assessment of addiction].

The "Questionnaire on Differentiated Assessment of Addiction (QDAA)" is a multi-modal, selfrating instrument for the Assessment of addiction and abuse of psychotropic substances. The QDAA provides the diagnosis of addiction as well as an overview of relevant information needed for the treatment of addiction. Several subscales assess variables that contribute to the development and maintenance of addiction such as mood, stress, expectancy of drug effects, self-esteem, life satisfaction and coping ability. In the present study validity and reliability of the QDAA was tested in several dependent and non-dependent samples. A total of 575 non-dependent, alcohol-, heroin- and cannabis-dependent subjects was available for the present study. Six criteria (craving, tolerance, withdrawal, loss of control, addictive behavior, negative consequences), that form the basis of the addiction diagnosis were shown to have high internal consistency and can be reduced to one dimension by factor analysis. The resulting diagnosis of addiction is significantly correlated with the external criterion "dependence syndrome" of the ICD-10 by external experts. The assumed structure of the QDAA-subscales could be confirmed by factor analysis. In addition, the results of the subscale analysis provide empirical evidence for convergent validity. All subscales showed moderate to high internal consistency. The results suggest that the QDAA is a valid and reliable instrument for the differential assessment of substance addiction, abuse as well as relevant information in the context of addiction and its treatment.