ABSTRACT
<p><b>OBJECTIVE</b>To study the prevalence of internet use and internet addiction in adolescents of Shanghai.</p><p><b>METHOD</b>From September to October 2007, a total of 5135 adolescents from 16 middle schools of 6 districts of Shanghai took part in the epidemiological study by a cross-sectional survey and 5123 adolescents finally enrolled in the study. A questionnaire of "DRM Adolescent Internet Use 52 Scale" was administrated to investigate the prevalence of internet use and internet addiction in adolescents of Shanghai. On this scale of 5-point rating, the scale includes seven parts of contents as tolerance, abstinence reaction, planning ability, self-control ability, whenness, sociability and hazard.</p><p><b>RESULTS</b>The rate of internet use among the surveyed adolescents was 94.32% (4673/5123), among which the incidence rate of internet addiction was 8.78% (450/5123). Boys, senior middle-school students were more susceptible to internet addiction than girls and junior middle-school students (male scores 122.42+/-43.46, female scores 116.92+/-38.10, F=23.22, P=0.00; senior middle-school students 125.24+/-39.02, junior middle-school students 110.30+/-42.35, F=164.68, P=0.00). Students from vocational senior middle-school were most susceptible (junior middle-school students 110.30+/-42.35, ordinary senior middle-school students 122.83+/-40.99, key senior middle-school students 120.05+/-37.87, vocational senior middle-school students 133.37+/-36.84, F=34.44, P=0.00). The 2nd grade students of senior middle-school have the highest risk for internet-addiction.</p><p><b>CONCLUSION</b>The prevalence of internet use and internet addiction in adolescents of Shanghai should be comparatively high in China, which indicates that great attention should be paid to the prevention and control.</p>