Survey on validity and reliability of diagnostic questionnaire of internet addiction disorder in students users

Internet occupies a large part of youth's life and each year more reports are published a bout Internet addiction disorder (IAD).This study argues the validity and reliability of Young Diagnostic Questionnaire (YDQ) correspondence Iranian society and culture. This is a cross-sectional and descriptive-analytical research. For these purpose 400 students of Isfahan universities were subjected. Sampling method was quota sampling. Cases completed demographic questionnaire, Compulsive Internet Use Scale (CIUS) and YDQ (Young Diagnostic Questionnaire). Finally we performed a psychiatric interview (based on DSM-IV-TR) for all of the samples. For data analysis we used face, discriminative and concurrent validity, Chronbach α, split half, test-retest and ROC Curve by SPSS-14 Software. Concurrent validity was (r=0.78, 0.81), discriminative validity was (r=0.62). Besides YDQ shows internal consistency (α=0.70), split-half validity(r=0.64), test –retest reliability (r=0.74, p<0.01). The best cut off point for this questionnaire is number 4. The result showed that Persian version of YDQ is valid and reliable. Considering lack of a valid and reliable questionnaire for measuring addiction to the internet, YDQ could be a suitable tool for measuring internet addiction in future research.