Comparability of sleep disorders diagnoses using DSM-IV and ICSD classifications with adolescents.

STUDY OBJECTIVES: The use of diagnostic classifications to define sleep disorders is still unusual in epidemiological studies assessing the prevalence of sleep disorders in an adolescent population.

DESIGN: Cross-sectional study. Representative samples of general populations in United Kingdom, Germany and Italy were selected and interviewed by telephone about their sleep habits, sleep and mental disorder diagnoses. Overall, 724 adolescents ages 15-18 years and 1447 young adults ages 19 to 24 years were interviewed. ICSD-90 and DSM-IV diagnoses provided by the Sleep-EVAL expert system were used for the comparisons.

SETTING: N/A.

PARTICIPANTS: N/A.

INTERVENTIONS: N/A.

MEASUREMENTS AND RESULTS: 8% of the adolescents and 12.6% of the young adults had ICSD dyssomnia or sleep disturbances associated with a mental disorder. According to the DSM-IV classification, 5.7% of the adolescents and 8.1% of the young adults had a dyssomnia diagnosis. The comparison between the two classifications show that 73.2% of adolescents and young adults with a DSM-IV dyssomnia diagnosis also had similar ICSD diagnosis. The reverse comparison, ICSD vs. DSM-IV, shows that 39.8% of the subjects with an ICSD diagnosis had a DSM-IV diagnosis. DSM-IV primary insomnia was the most frequent diagnosis. Subjects with such a diagnosis were found in about 10 different ICSD diagnoses, mainly inadequate sleep hygiene, psychophysiological or idiopathic insomnia and insufficient sleep syndrome.

CONCLUSIONS: ICSD-90 classification provided higher prevalence of sleep disorder diagnoses than the DSM-IV classification. In adolescents and young adults, DSM-IV primary insomnia is two times more often associated with ICSD inadequate sleep hygiene than with ICSD psychophysiological or idiopathic insomnia.