Structured psychiatric interview and ambulatory sleep monitoring in young psychophysiological insomniacs

Background: The presence of psychiatric disorders (according to DSM- III-R), the discriminating power of a psychiatric structured interview, and sleep monitoring were investigated in psychophysiological insomnia. Method: Forty young (20-40 years old) patients, selected for putative psychophysiological insomnia, underwent a psychiatric structured interview and home ambulatory sleep monitoring for 2 nights. The results were compared with those of a group of nine young normal sleepers. Results: 48% of the insomniacs showed some psychiatric disorders, while 52% did not meet DSM- III-R criteria for a psychiatric diagnosis. Both groups, but not the controls, showed a slight first-night effect in the sleep analysis. The sleep structure of all insomniacs was found to be disturbed, mainly in sleep continuity, but essentially the two groups showed no significant differences. When we used a stepwise logistic regression analysis, the number of sleep stage shifts (indicating sleep instability) was the best variable in discriminating the insomniacs from controls, but not the patients with psychiatric disturbances from those without psychopathologies. Conclusion: The evaluation of young insomniacs with a structured psychiatric interview rather than with ambulatory sleep monitoring seems to be most useful in discriminating between patients with only psychophysiological insomnia and patients with both insomnia and an associated diagnosis of another mental disorder.